ETAS_MCQ_12 bullous diseases and blistering


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ETAS_MCQ_12 bullous diseases and blistering

  1. 1. Bullous diseases and blistering1) Which pair is incorrect?A. Lichen planus : linear C3 Correct ChoiceB. Bullous pemphigoid : linear C3C. IgA pemphigus: intercellular IgAD. Dermatitis herpetiformis : granular IgAE. Systemic lupus erythematosus : linear IgGThe colloid bodies in lichen planus can trap IgM and C3; this can be seen on DIF as “globs.” There isno linear pattern2) In penicillamine-induced pemphigus, the split is most often:A. Subcorneal Correct ChoiceB. SubepidermalC. SuprabasalD. Intraepidermal and subepidermalE. IntraspinousPenicillamine is the most common cause of drug-induced pemphigus, and the split is more oftensubcorneal (pemphigus foliaceus-like) than suprabasal (pemphigus vulgaris-like).3) Herpes gestationis is exacerbated by:A. Postpartum stateB. Oral contraceptivesC. All of these answers are correctCorrect ChoiceD. Third trimesterE. MenstruationHerpes gestationis has also been associated with choriocarcinoma in several case reports4) Common drugs causing SJS/TEN include all except:A. CarbamazepimeB. AllopurinolC. SulfonamidesD. OxicamE. Colchicine Correct ChoiceNSAIDs, anticonvulsants, allopurinol, and sulfa drugs are common inciting agents of SJS/TEN5) This is derived from Myroxylon pereirae:A. Aniline dyes 1
  2. 2. B. ThimerosolC. ThiuramD. ColophonyE. Balsam of Peru Correct ChoiceBalsam of Peru is derived from the Myroxylon pereriae tree. Thimerosal is a questionable cause ofallergic contact dermatitis; it is found in vaccines and contact lens solutions6) In Brunsting-Perry pemphigoid, the recrurrent crops of blisters are most likely to appear on:A. Head and neckCorrect ChoiceB. UmbilicusC. GenitalsD. ButtocksE. Palms and solesBrunsting-Perry pemphigoid is a variant of cicatricial pemphigoid in which there are no mucosallesions. The most common site of blisters is the head and neck, resulting in scarring alopecia. Theantigens in cicatricial pemphigoid include BPAg2 and epiligrin7) The croton plant is irritating secondary to:A. ThiocyanateB. CapsaicinC. ProtoanemoninD. Calcium oxalateE. Phorbol esters Correct ChoiceIrritant contact dermatitis secondary to the croton plant is due to phorbol esters. Calcium oxalate isalso an irritant; it is found in the “dumb caine” plant, a common house plant (Dieffenbachia) as wellas in daffodils. Thiocyanates are irritants found in garlic. Protoanemonins are irritants found inbuttercups8) Circulating autoantibodies to type XVII collagen are most characteristic of which disease?A. Epidermolysis bullosa accquisitaB. Paraneoplastic pemphigusC. Pemphigus vulgarisD. Pemphigus foliaciousE. Herpes gestationisCorrect ChoiceType XVII collagen or BPAG2 is a transmembrane protein found in the hemidesmosome.Autoantibodies to type XVII collagen are important in the pathogenesis of cicatricial pemphigoid,bullous pemphigoid, and herpes gestationis9) What is the enzyme defect in Gunthers disease?A. Protoporphyrinogen oxidase 2
  3. 3. B. Uroporphyrinogen synthetase IIICorrect ChoiceC. Uroporphyrinogen decarboxylaseD. FerrochetalaseE. Porphobilinogen deaminaseGunthers disease (also known as congenital erythropoietic porphyhria) is caused by a defect inuroporphyrinogen synthetase II, the enzyme which responsible for the conversion ofhydroxymethylbilane to uroporphyriogen III. Patients present with red teeth and immediatephotosensitivy during infancy. There is severe photophobia and late skin manifestations includemutilating scarswith scarring alopecia, and sclerodermoid changes10) Which form of epidermolysis bullosa presents with generalized bullae, absent nails, dysplasticteeth (due to enamel defects), nonhealing granulation tissue periorally, and is often fatal by age3-4?A. Hyperplastic cockayne-touraineB. Albapapuloid Pasini variantC. HerlitzCorrect ChoiceD. Weber-cockayneE. Non-HerlitzJunctional EB is an autosomal recessive disorder with a defect in the lamina lujcida; uncein is absentin all forms. The Herlitz variant is due to mutations in laminin 5 and clinically presents asgeneralized bullae (which are non-scarring), nonhealing granulation tissue periorally, absent nails,dysplastic teeth and enamel defects, anemia, growth retardation and is often fatal by age 3-4 dueto low protein, anemia and infection. The non-Herlitz variant of Junctional EB presents with bullaeespecially on the extremities which heal with atrophic scarring; pts improve with age and typicallyhave a normal life span. Weber-cockayne is a type of EB simplex and presents with palmoplantarbullae and hyperhidrosis. Hyperplastic cockayne-touraine is a form of dominant dystrophic EB whichpresents with bullae localized to extremities. Albapapuloid Pasini variant of dystropohic EB presentswith widespread bullae, atrophy, hypopigmented scar-like white papules on trunk, no miliaar orscarring, and mild oral involvement11) Pemphigus erythematosus:A. Is often in a malar/seborrheic distribution Correct ChoiceB. Is also called Hallopeau syndromeC. All of these answers are correctD. Does not have linear IgG and C3 at the basement membrane zoneE. May be an abortive form of subcorneal pustulosisPemphigus erythematosus, or Senear Usher syndrome, presents like pemphigus foliaceus and lupuserythematosus with very superficial erosions and erythematous/hyperkeratotic facial/chest lesions.DIF reveals intercellular IgG and linear IgG at the dermoepidermal junction12) Patients with this disorder may develop exaggerated reactions to insect bites:A. Bullous pemphigoidB. Atopic dermatitisC. Chronic lymphocytic leukemia Correct Choice 3
  4. 4. D. Incontinentia pigmentiE. Lupus erythematosusPatients with chronic lymphocytic leukemia may develop exaggerated reactions to insect bites,including bullous reactions13) In staphylococcal scalded skin syndrome, the exfoliative toxin cleaves:A. Desmocollin 3B. Desmoglein 3C. Desmoglein 1Correct ChoiceD. Desmocollin 1E. BpAg2Staphylococcal scalded skin syndrome is caused by Staphylococci group 2, phage typ 71, whichproduces an exofliative toxin that cleaves desmoglein 1. Clinically, this results in a subcornealseparation of keratinocytes, leading to skin tenderness, erythema, and superficial desquamatioin ofskin14) Epidermolysis bullosa simplex is caused by mutations in:A. Keratins 1&10B. Keratins 5&14Correct ChoiceC. Keratins K2e&10D. Keratins 1&9E. Keratins 6a &16EB Simplex is caused by mutations in keratins 5 &14. Mutations in Keratins 1&10 are associatedwith epidermolytic hyperkeratosis ande Unna-thost. Mutations in keratins 1&9 are associated withepidermolytic palmoplantar keratoderma. Mutations in Keratins 6a and 16 are associated withPachyonychia congenital. Mutations in K2e and 10 are associated with Icthyosis bullosa of Siemens15) The agent most likely to cause pseudoporphyria is:A. Ace-inhibitorsB. VancomycinC. PenicillinD. Beta-blockersE. NSAIDsCorrect ChoiceNSAIDS,especially naprosyn, are the most common group of drugs implicated in pseudoporphyria.Other common offenders include lasix, tetracycline, accutane, amiodarone and tanning beds16) Which pair is incorrect?A. Type XVII collagen: 180 kDaB. Type VII collagen : 290 kDaC. Desmoplakin I : 250 kDa 4
  5. 5. D. Desmoglein 1 : 160 kDaE. Envoplakin : 190 kDa Correct ChoiceEnvoplakin is 210 kDa. Periplakin is 190 kDa17) Each of the following is true about anti-p200 pemphigoid except:A. Responsive to dapsoneB. Subepidermal bullaeC. 200-kd antigenD. features of linear IgA diseaseE. mucosal involvementCorrect ChoiceAnti-p200 pemphigoid is an autoimmune blistering disorder. These autoantibodies bind to a 200-kDantigen found at the lamina lucida-lamina densa interface, thereby causing a subepidermal bullae.Clinical features of this disease are similar to bullous pemphigoid, dermatitis herpetiformis andlinear IgA disease. In the case reported by Egan,, the patient responded well to steroids anddapsone and did not have mucosal lesions18) Common cause(s) of drug-induced pemphigus foliaceus:A. MethotrexateB. DilantinC. PenicillamineD. CaptoprilE. Captopril and penicillamine Correct ChoicePenicillamine and captopril are common causes of drug-induced pemphigus19) Chloracne may be secondary to exposure to:A. Dioxin Correct ChoiceB. MethylchloroisothiazolinoneC. ChloroacetophenoneD. HydrocarbonsE. Hydrochloric acidChlorinated compounds can cause irritant dermatitis and sometimes chloracne. Chlorinatedcompounds include chloronaphthalene, chlorodiphenyl, dichlorobenzonitrile,tetrachloroazooxybenzene; dioxin (exposure in the Vietnam war); and cutting oils.Chloroacetophenone is an irritant in tear gas20) Which association is incorrect?A. Porphyria cutanea tarda : hemochromatosisB. Epidermolysis bullosa acquisita : inflammatory bowel diseaseC. Paraneoplastic pemphigus : Castleman’sD. Herpes gestationis : menopause Correct Choice 5
  6. 6. E. Dermatitis herpetiformis : small bowel lymphomaNEEDS EXPLANATIONS21) Which autoantibodies would most likely be found in an individual with these eye findingswithout any cutaneous involvement?A. Alpha 6 beta 4 integrinCorrect ChoiceB. Laminin 5C. Bullous pemphigoid antigen 2D. DesmocollinE. Bullous pemphigoid antigen 1Cicatricial pemphigoid is a rare, heterogeneous group of blistering diseases with predilection formucous membranes. It may involve the eyes, oral mucosa, genital/anal mucosa, and skin. Theocular form of cicatricial pemphigoid without cutaneous findings is usually associated withcirculating autoantibodes to alpha 6 beta 4 integrin22) Which of the following is the most common photoallergen?A. glyceryl thioglycolateB. DihydroxyacetoneC. octyl dimethyl PABAD. BenzophenoneE. OxybenzoneCorrect ChoiceOxybenzone is a UVA sunscreen and is the most common photoallergen. Octyle dimethyl PABA(Padimate O) and benzophenone are also sunscreen agents, and both can also cause contactdermatitis. Dihydroxyacetone is a sunless-tanning agent and glyceryl thioglycolate is found inpermanent wave solutions23) Oriental" tiger balm cross-reacts with:A. LanolinB. NeomycinC. Balsam of PeruCorrect ChoiceD. RosinE. Ylang-Ylang oil"Oriental" tiger balm is a popular Chinese proprietary ointment used to relieve aches and pains.Patients who develop allergic contact dermatitis to this agent have also been shown to have cross-reactions with balsam of Peru. A similar substance known as "Bavarian" tiger balm has beenreported to cross react with rosin24) Patients with Duhrings disease are most likely to have:A. Antibodies to BPAg2B. Mutations in transglutaminase IC. Antibodies to transglutaminase 3Correct Choice 6
  7. 7. D. Mutations in laminin 5E. Mutations in plectinDuhrings disease is also known as dermatitis herpetiformis. Antibodies are found totransglutaminase 3, and the direct immunofluorescent studies show granular IgA and C3 in thedermal papillae. Mutations in plectin are found in EBS with muscular dystrophy. Mutations in laminin5 are found in patients with JEB,Herlitz type. Mutations in transglutaminase I are found in pateintswith lamellar ichthyosis and non bullous congenital ichthyosiform erythroderma25) Cleavage of this adhesion molecule is seen in Staphylococcal Scalded Skin Syndrome:A. Desmoglein 1 Correct ChoiceB. Desmoplakin 2C. Desmoplakin 1D. Desmoglein 3E. Desmoplakin 1 and desmoplakin 2Desmoglein 1 is cleaved by exfoliative toxin in Staphylococcal scalded skin syndrome26) Gallstones are associated with:A. HarderoporphyriaB. CoproporphyriaC. Variegate porphyriaD. Hepatoerythropoietic porphyriaE. Erythropoietic protoporphyria Correct ChoiceGallstones and liver failure can complicate erythropoietic protoporphyria27) What is the antigen associated with dermatitis herpetiformis?A. Tissue transglutaminaseCorrect ChoiceB. DesmocollinC. EpilegrinD. Desmoglein 3E. PeriplakinDermatitis herpetiformis is an autoimmune blistering disease associated with intense pruritus.Classically, it involves the extensor aspects of the body. Antibodies to tissue transglutaminase (anti-endomesial, anti-gliadin, anti-reticulin) can be found. It is associated with celiac sprue. 50% havethyroid disease28) Which of the following chemicals is the most common cause of shoe contact dermatitis?A. Carba mixB. Mixed dialkyl thioureasC. Thiuram mixD. 2-MercaptobenzothiazoleCorrect Choice 7
  8. 8. E. Formaldehyde2-Mercaptobenzothiazole is found in the soles of shoes, and is the #1 cause of shoe contactdermatitis. It is also found in rubber accelerators, adhesives/tape, coolants, rubber, flea/tickpowder, and support hose. Thiuram mix, carba mix, and mixed dialkyl thioureas are also rubbersensitizers. Thiuram is the second most frequent source of shoe contact dermatitis. Formaldehyde isa preservative and not found in shoes29) Which of the following is true of a phototoxic reaction?A. Develops after repeated exposuresB. Results in direct tissue injuryCorrect ChoiceC. Requires prior sensitization of photoallergen in susceptible individualsD. Photoallergen must bind to carrier proteinE. Produces an eczematous reactionPhototoxic reactions result in direct tissue injury when the phototoxic agent interacts with lightenergy to form reactive oxygen species. It is characterized by an eruption similar to a sunburn30) This is found in both desmosomes and adherens junctions:A. LaminB. Desmoglein 1C. Plakoglobin Correct ChoiceD. Desmoglein 3E. Alpha-cateninPlakoglobin is a plaque protein of the armadillo family that is found in desmosomes; it can alsosubstitute for beta-catenin in adherens junctions. Plakoglobin co-precipitates with desmogleins. It is85 kDa31) Epidermolysis bullosa simplex with muscular dystrophy is associated with a mutation in:A. collagen VIIB. PlectinCorrect ChoiceC. alpha 6 beta integrinD. Laminin 5E. unceinEB Simplex is an autosomal dominant disorder caused by mutations in keratins 5 &14, leading tointraepidermal bullae. A subtype of EBS patients have muscular dystrophy due to a defect in plectin.Laminin 5 mutations are associated with junctional EB. Collagen VII mutations are associated withdystrophic EB. Uncein is a protein in the lamina lucida which is found to be absent in junctional EB.Mutations in alpha6-beta4 integrins are associated with JEB with pyloric atresia32) Perioral exuberant granulation tissue is sometimes seen in:A. Duhring’sB. Weber-Cockayne 8
  9. 9. C. Cicatricial pemphigoidD. Herlitz Correct ChoiceE. Weber-CockayneThe Herlitz form of junctional EB sometimes presents with excessive granulation tissue periorally, inthe axillary/neck area33) Irritation of the hand produced by capsaicin can be relieved by application ofA. Sodium chlorideB. AlkaliC. Acetic acid 5% Correct ChoiceD. WaterE. Talcum powderBurning secondary to capsaicin can be relieved by vinegar (acetic acid 5%) as the capsaicin issoluble in vinegar (but not water).34) Which of the following can be responsible for contact dermatitis to K-Y Jelly?A. Alpha tocopherolB. BudesonideC. Lanolin alcoholD. TriclosanE. Propylene glycolCorrect ChoicePropylene glycol is a widely used solvent and humectant found in a variety of products such ascosmetics, lotions, corticosteroids, antiperspirants, and K-Y jelly. Lanolin is an emollient whichcomes from wool wax and is found in adhesives, cosmetics, and topical emollients such asAquaphor. Budesonide is a steroid, alpha tocopherol is topical Vitamin E, and Triclosan is a topicalantibiotic35) What is the most common allergen causing allergic contact dermatitis?A. Quaternium-15B. BacitracinC. FormaldehydeD. Nickel Correct ChoiceE. NeomycinNickel is the most common contact allergen, found in “costume” jewelry, alloys, pigmentsorthopedic appliances, scissors, razors and many other metal coated objects. Bacitracin andneomycin are commonly used topical antibiotic agents that many are allergic to. Neomycin is themost common topical antibiotic allergen found in testing. Quaternium-15 is a formaldehyde-releasing preservative found in many topical products. It can cross react with formaldehyde, but notall patients will react to formaldehyde on testing. While it is a common allergen, it is not the mostcommon cause of ACD36) The primary autoantigen in pemphigoid gestationis is 9
  10. 10. A. PlakoglobinB. DesmoplakinC. BPAG1D. Anchoring fibrilsE. BPAG2Correct ChoiceHerpes gestationsis is an autoimmune blistering disorder of pregnancy. It is characterized byurticarial plaques and tense bullae. Antibodies to BPAG2 are thought to form as a result of anaberreant response to MHC antigens on the placenta. The maternal health is generally not affected,but infants are more commonly born premature. Remission is common following delivery, but it mayrecur with OCPs, menstruation, and subsequent pregnancies37) Which of the following proteins is typically NOT found to be antigenic in paraneoplasticpemphigus?A. PeriplakinB. BPAg2Correct ChoiceC. EnvoplakinD. BPAg1E. DesmoplakinBPAg2, a 180kDa protein, is typically not found to be antigenic in paraneoplastic pemphigus. Theproteins typically involved are:p desmplakin 1 (250kDa)p BPAg1 (230 kDa)p Envoplakin (210kDa)p Desmoplakin 2(210kDa)p Periplakin (190 kDa)p Unknown protein (170 kDa)p Desmogleins 1& 3 (160 and 130 kDa38) The epidermolysis bullosa acquisita antigen is:A. Located in the lamina lucidaB. A desmosomal proteinC. A transmembrane proteinD. An intracellular proteinE. An anchoring fibrilCorrect ChoiceEpidermolysis bullosa acquisita is a rare autoimmune disorder with an estimated incidence of 0.25per million. In the classic form, it is characterized by non-inflammatory bulla with a prediliction fortraumatized sites. The autoantigen is type VII collagen, which is an anchoring fibril located in thesublamina densa. Following salt split skin, the type VII collagen can be localized at the base39) The most common malignancy associated with paraneoplastic pemphigus is:A. Chronic lymphocytic leukemiaB. Acute myelocytic leukemiaC. Non-Hodgkin’s lymphoma Correct Choice 10
  11. 11. D. Multiple myelomaE. Hodgkin’s lymphomaParaneoplastic pemphigus is associated with various benign as well as malignant internal tumors,with the most common being non-Hodgkin’s lymphoma40) What is the antigen in penicillamine induced pemphigus?A. Desmoglein 1B. PlakoglobinC. DesmocollinCorrect ChoiceD. Desmoglein 3E. Tissue transglutaminasePenicillamine is chelating agent that is used in the treatment of Wilsons disease and rheumatoidarthritis. It has implicated in many drug reactions including drug induced pemphigus and elastosisperforans serpiginosa. In penicillamine induced pemphigus, desmocollin is the autoantigen41) What percentage of dermatitis herpetiformis patients are asymptomatic but have findingsconsistent with celiac sprue on gastrointestinal biopsy?A. 15%B. 95% Correct ChoiceC. 40%D. 70%E. 5%Most patients with dermatitis herpetiformis have findings consistent with celiac disease on biopsy,but not all of them are symptomatic42) Which neoplasm is the most common cause of paraneoplastic pemphigus?A. CLLB. ThymomaC. Castlemans diseaseD. Non-Hodgkins lymphomaCorrect ChoiceE. Retroperitoneal sarcomaAll of the above have been associated with paraneoplastic pemphigus with non-Hodgkins lymphomabeing the most common. Castlemanss disease is most common in children with paraneoplasticpemphigus43) The defect in junctional epidermolysis bullosa occurs at the:A. Lamina densaB. Lamina lucidaCorrect ChoiceC. Granular layerD. Sublamina densa 11
  12. 12. E. Spinous layerJunctional epidermolysis bullosa is an autosomal recessive disorder characterized by a defect in thelamina lucida. The protein uncein, a molecule which binds the gamma chain of laminin anda6b4/BPAg1, is absent in all forms of junctional EB. Uncein is normally found in the lamina lucida,along with lamin 1, laminin 5, laminin 6m, heparan sulfate proteoglycan, and fibronectin44) Antibodies in chronic disease of childhood disease map to the:A. Lamina densaB. Lamina lucida and sublamina densaCorrect ChoiceC. Sublamina densaD. Lamina lucidaE. Basal layerImmunoelectron mapping of chronic disease of childhood has shown binding within the laminalucida as well as in the sublamina densa. This correlates with the finding of the 97-kDa antigen thatis homologous to a portion of the BPAg2 molecule as well as a 280-290 kDa antigen in this disease.Some have suggested that the 280-290 kDa antigen is type VII collagen, but the former does notco-migrate with type VII collagen on Western blots45) Th2-related cytokines include:A. All of these answers are correctB. IL10 Correct ChoiceC. IFNgammaD. IL10 and IFNgammaE. IFNalphaAtopic dermatitis is considered a disease in which a Th2 pattern predominates, especially early on.Th2 cytokines are IL4, IL5, IL6, IL10, IL1346) An elderly gentleman with a history of hypertension and a thymoma, presents to theEmergency Room with oral and conjunctival erosions and hemorrhagic bullae on his hands and feet.These finds are seen in:A. Toxic epidermal necrolysisB. Sweet’s syndromeC. Cicatricial pemphigoidD. Erythema multiformeE. Paraneoplastic pemphigusCorrect ChoiceParaneoplastic pemphigus is usually associated with cancers of lymphoid origin, includinglymphoma, leukemia, thymomas, Castleman’s tumor. Clinically, this condition may present withintractable staomatitis, severe painful oral and conjunctival erosions47) Herpes gestationis is most commonly associated with:A. Hashimoto’sB. Lupus 12
  13. 13. C. Rheumatoid arthritisD. DiabetesE. Grave’s Correct ChoiceAutoimmune diseases are associated with herpes gestationis; Grave’s disease is the most commonassociation48) Which of the following adhesion molecules are important for maintaining adhesion betweenkeratinocytes?A. Immunoglobulin superfamilyB. SelectinsC. IntegrinsD. GlycansE. CadherinsCorrect ChoiceCadherins mediate cell adhesion and play a fundamental role in normal development. Calicum isrequired for the normal function of these adhesion molecules. There are two main subclasses,classic (E-, P-, N-) and desmosomal (desmoglein and desmocollin).49) The dimethylglyoxime test is used to detect the presence of:A. NickelCorrect ChoiceB. GoldC. MercuryD. SilverE. Latex1% dimethylglyoxime is added to to the metal. If a red precipitate forms, there is >1:10000 nickelcontent50) A one-day old infant presens with papules and pustules on the face, trunk, and proximalextremities. Palms and soles are spared. The patient is otherwise doing well. A biopsy showsnumerous eosinophils. The diagnosis is:A. Transient neonatal pustular melanosisB. Herpes infectionC. ScabiesD. Erythema toxicum neanotorumCorrect ChoiceE. Acropustulosis of infancyPapule and pustules on an erythematous base appear on a healthy infant within 48 hours, andtypically last 2-3 days in erythema toxicum neanotorum. The lesions may occur anywhere, butusually spare the palms and soles. Gram stain reveals numerous eosinophils. A 1 day-old infantwould not have had a chance to acquire a scabies infestation. Acropustulosis of infancy typicallypresents at 3-4 months and the pathology shows vesicles with many neutrophils. A herpes infectionwould not show eosinophils. Transient neonatal pustular melanosis showsw sterile subcornealpustules 13
  14. 14. 51) Which type of porphyria manifests with peripheral neuropathy, colicky abdominal pain, but NOcutaneous symptoms?A. Erythropoietic protopophyriaB. Variegate porphyriaC. Gunthers diseaseD. Acute Intermittent PorphyriaCorrect ChoiceE. Hereditary CopropophyriaAcute intermittent pophyria is caused by a defect in the enzyme porphobilinogen deaminase.Patients present with peripheral neuropathy and occasionally seizures, abdominal pain, andtachycardia. There are no skin changes as no dermal porphyrins are found52) Gap junctions consist of:A. PlectinB. FilagrinC. ConnexinsCorrect ChoiceD. LamininE. UnceinGap junctions are protein channels that allow for communcation between cells. A connexon of onecell is joined to that of an adjacent cell to form an intercellular channel consisting of 12 connexinsubunits. Each intercellular channel provides a channel that interconnects the cytoplasm of theapposed cell directly and permits the passage of ion and other small molecules between adjacentcells.These protein channels that make up the gap junctions consist of two “hemi-channels” orconnexons. One connexon resides in the membrane of one cell and it aligns and joins the connexonof the neighboring cell, forming a continous aquaeous pathway by which these ions and smallmolecules can freely pass from one cell to the other. Each hemi-channel or connexon consist of sixproteins ( hexamer) called connexins53) Which steriod screening agent should be used when an allergic contact dermaititis is suspectedto hydrocortisone?A. GlutaralB. BudesonideC. Hydrocortisone-17-butyrateD. Tixocortol-21-pivalateCorrect ChoiceE. Benzalkonium chlorideTixocortol-21-pivalate is a group A steroid and screens for allergies to hydrocortisone, prednisone,and methylprednisolone. Budesonide screens for groups B and D steroids, and hydrocortisone-17-butyrate screens for group D steroids54) Paraneoplastic pemphigus:A. Is most often seen in association with lung cancerB. Does not remit even if the cancer is excised completely 14
  15. 15. C. Is characterized by a pathognomonic 250 kDa antigenD. All of these answers are correctE. May be caused by a benign neoplasm Correct ChoiceParaneoplastic pemphigus can be caused by lymphoma as well as other malignancies. It can also besecondary to benign thymomas and Castleman’s disease. Numerous antigens have been found,including desmoplakin I and II. Desmoplakin I and II may be antigenic in Stevens-Johnsonsyndrome55) Direct immunofluorescent studies in a patient with bullous pemphigoid is most likely to show:A. Linear C3 at the basemement membraneCorrect ChoiceB. C3 in the dermal papillaeC. Granular IgA in dermal papillaeD. Intercellular IgG4 throughout the epidermisE. Linear IgA at the basement membraneIn bullous pemphigoid, the antigenic targets are believed to be BPAg1 and BPAg2-NC16A domain.These proteins are located in the hemidesmosome. Direct immunofluorescent studies reveal linearbasement membrane C3in approximately 95% of patients, and IgG4 in approximately 80%. LinearIgA is found in linear IgA and chronic bullous deiseasaeof childhood. Granular IgA and C3 in thedermal papillae is found in dermatitits herpetiformis. Intercellular IgG4 throughout the epidermis isfound in pemphigus vulgaris56) Bullous lesions are seen in:A. Tertiary syphilisB. Primary syphilisC. Secondary syphilisD. Congenital syphilis Correct ChoiceE. All of these answers are correctCongenital syphilis, but not other forms of syphilis, can occasionally present with bullae57) Papillary dermal deposits of IgA and a papillary dermal infiltrate of neutrophils is diagnostic of:A. Bullous pemphigoidB. Linear IgA dermatosisC. Sweets syndromeD. Leukocytoclastic vasculitisE. Dermatitis herpetiformisCorrect ChoiceDermatitis herpetiformis is an uncommon chronic, pruritic papulovesicular dermatitis occurring mostcommonly in young to middle-aged adults. Common sites of predilection include the buttocks,elbows, knees, scapula and scalp. Typical histologic features include accumulation of neutrophils atthe tips of dermal papillae, sometimes admixed with eosinophils. Direct immunoflorescence (DIF)reveals granular deposits of IgA within the dermal papillae.As the name implies, linear IgA disease is characterized by linear IgA deposition along the basementmembrane zone with DIF in 100% of cases. The pattern of direct immunoflorescence in bullouspemphigoid is linear C3 deposition at the dermoepidermal junction in nearly 100% of cases and IgGin 65-95% of cases. Sweets syndrome is not characterized by a pattern with DIF. Under light 15
  16. 16. microscopy, a dense perivascular infiltrate of neutrophils is seen assuming a bandlike patternthroughout the papillary dermis associated with prominent dermal edema. Leukocytoclasticvasculitides are characterized by a perivascular neutrophilic infiltration with karyorrhexis,leukocytoclasis, fibrinoid degeneration, and endothelial swelling58) Which type of porphyria disease is most likely to be associated with cholelithiasis?A. Acute intermittent porphyriaB. Hereditary coproporphyriaC. Congenital erythropoeitic porphyriaD. Variegate porphyriaE. Erythropoetic protoporphyriaCorrect ChoiceErythropoeitic protoporphyria is caused by a defect in the enzyme ferrrochetalase. Patients presentwith immediate photosensitivity and subsequently develop waxy scarring on the face, hands andknuckles. In addition to abdominal pain, cholelithiasis and liver disease may also occur. Theporphyria diseases associated with abdominal pain are acute intermittent porphyria, hereditarycoproporphyria and variegate porphyria. Congenital erythropoeitc porphyria is associated withsplenomegaly59) Atopic dermatitis is associated with all except:A. Lchthyosis hystrix Correct ChoiceB. Central facial pallorC. Pityriasis albaD. Hyperlinear palmsE. Nipple eczemaIcthyosis vulgaris (not hystrix) is associated with atopic dermatitis as one of the minor criteria ofHanifin60) Antibodies against type VII collagen are seen in:A. Epidermolysis bullosa acquisitaCorrect ChoiceB. Cicatricial pemphigoidC. Pemphigus erythematosusD. Epidermolysis bullosa simplexE. Bullous pemphigoidType VII collagen is present in the basement membrane of stratified squamous epithelia in theanchoring fibrils. It is the target antigen in several blistering disease including epidermolysis bullosaacquista, bullous lupus erythematosus, dominant and recessive dystrophic epidermolysis bullosa61) This is associated with deafness:A. CadherinB. DesmoplakinC. Claudin 16
  17. 17. D. DesminE. Connexin Correct ChoiceConnexin 26 is associated with PPK and deafness. Mutations in this same connexin is associatedwith Vohwinkel’s and KID syndromes62) Patients with Senear-Usher syndrome are most likely to present with:A. Erythematous crusts and hyperkeratotic lesions on the nose, ears, cheeks, scalp, andchestCorrect ChoiceB. Transient vesicles on the oral mucosaC. Erythematous papules and plaques around the umbilicusD. Erythema multiforme-like oral ulcerations which are severeE. Severely pruritic grouped vesicles symmetrically distributed primarily on extensor surfacesSenear-Usher syndrome, also known as pemphigus erythematosus, is thought to be an overlapbetween lupus erythematosus and pemphigus foliaceous. The histology resembles that ofpemphigus foliaceous with linear IgG at the dermoepidermal junction. 80% of patiens have apositive lupus band63) The vector of fogo selvagem may be:A. TriatomaB. MusC. Simulium Correct ChoiceD. OrnithodorusE. CimexFogo selvagem is considered to be an endemic form of pemphigus foliaceus, first described in Brazil,in rural areas where Simulium (black fly) is often found. Subsequently, other rural South Americanareas have had clusters of affected patients64) Formaldehyde releasers include all except:A. Methylchoroisothiazolinone Correct ChoiceB. DMDM hydantoinC. GermallD. DowicilE. Quaternium – 15Methylchloroisothiazolinone is also known as Kathon CG and it is a preservative. Germall,quaternium 15 (dowicil 200), DMDM hydantoin, and others are formaldehyde-releasingpreservatives65) Which of the following immunosuppressive agents has been most effective in cicatricialpemphigoid?A. AzathioprineB. Cyclophosphamide Correct Choice 17
  18. 18. C. CyclosporineD. MethotrexateE. Mycophenolate mofetilCicatricial pemphigoid is a heterogeneous group of subepithelial blistering diseases involving themucous membranes and skin. The treatment of cictracial pemphigoid is predicated upon the extent,severity, and location of disease. Most regimens used are empiric and are based on clinicalexperience. With severe ocular involvement, most experts recommend aggressive treatment withthe combination of cyclophosphamide and steroids66) Bullous lupus erythematosus is most commonly associated with antibodies to:A. PlectinB. Desmoglein IC. Type VII collagenCorrect ChoiceD. Laminin 5E. Type XII collagenType VII collagen is found in the sublamina densa and patients with bullous lupus erythematosushave been found to have antibodies to this protein. The histology can resemble that of dermatitisherpetiformis and DIF shows linear IgG, IgM, IgA and C3.67) What is the most common site of involvement of this autoimmune blistering disease?A. Nasopharyngeal mucosaB. EyesC. GenitaliaD. SkinE. Oral mucosaCorrect ChoiceCicatricial pemphigoid is a heterogeneous group of diseases with characteristic involvement of theoral mucosa, eyes, skin. Rarely, it can also involve the nasopharyngeal mucosa, external genitalia,esophagus, and anus. The oral mucosa is the most common site of involvement68) What is the primary irritant found in garlic and onions?A. DiallyldisulfideCorrect ChoiceB. Glycoside ranunculinC. CapsaicinD. GlochidsE. Calcium oxalateGarlic is a potent irritant that can cause 2nd and 3rd degree burns on the fingertips of homemakersand chefs. The irritant responsible for this reaction is diallyldisulfide69) The ocular form of cicatricial pemphigoid is most likely to be associated with antibodies to:A. BPAg1 18
  19. 19. B. Beta-4-integrinCorrect ChoiceC. BPAg2-NC16AD. Laminin 5E. PlectinAntibodies to beta-4-integrin are associated with ocular cicatricial pemphigoid. Laminin 5 isassociated a variant of cicatricial pemphigoid that is associated with malignancy. BPAg1 is theantigen in bullous pemphigoid, while BPAg2-NC16A is associated with both bullous pemphigoid andherepes gestationis. Mutations in plectin are associated with epidermolysis bullosa acquisita withmuscular dystrophy70) Transient bullous disorder of childhood has a defect in:A. PlectinB. Collagen VII Correct ChoiceC. Alpha6-integrinD. BPAg2E. EpiligrinTransient bullous dermolysis of the newborn may be a forme fruste/variant of dominant dystrophicEB. Mutations have been found in type VII collagen71) Nickel can be detected in jewelry by applying:A. DowicilB. QuinoneC. ThiocyanateD. Dimethylglyoxime Correct ChoiceE. MethylchloroisothiazolinoneDimethylglyoxime application to metals containing nickel will show a pink color.Methylchloroisothiazolinone is Kathon CG, a preservative. Dowicil is a formaldehyde-releasingpreservative. Primin is a type of quinone, and it is the allergen in primrose (Primula obconica).Thiocyanates are the irritating substances in garlic72) Leiner’s disease (erythroderma desquamativum) is associated with:A. C5-9 deficiencyB. Numerous infectionsC. Numerous infections and diarrhea Correct ChoiceD. All of these answers are correctE. DiarrheaLeiner’s disease is associated with deficient C5 and possibly C3. Babies with this disease are proneto diarrhea, infections (sepsis), anemia, and a generalized seborrheic dermatitis-like rash73) Which of the associated antigens for this condition has been associated with colon cancer? 19
  20. 20. A. Beta-4 integrinB. Anti-epiligrinCorrect ChoiceC. 97 kD linear IgA dermatosis antigenD. DesmoplakinE. Bullous pemphigoid antigen 2While the oral mucosa is the most common site for cicatricial pemphigoid, ocular involvement isvery common. Clinical manifestations may include shortened fornices, symblephera,ankyloblephera. The majority of of ocular antigens are thought to reside in the cytoplasmic domainof beta-4 integrin74) Which is incorrect?A. Sesquiterpene lactones : artichokesB. Urushiol : anacardiaC. Usnic acid : lichenD. Diallyl disulfide : fig Correct ChoiceE. Tulipalin : alstroemeriaTulipalin A is a byproduct of tuliposide A metabolism, and it is the allergen in alstroemeria, thePeruvian lily, and tulips. Urushiol is the allergen in Toxicodendron plants as well as several othercross-reactors including cashew nut shells (Anacardium occidentale). Artichokes are in the familyAsteraceae (formerly Compositae); this family is allergenic secondary to sesquiterpene lactones.Lichens contain usnic acid. The fig tree is in the family Moraceae, which is one of the plant familiesthat can cause phytophotodermatitis75) Clumped tonofilaments are seen on electron microscopy in:A. Vohwinkel’s syndromeB. Gunther’sC. Naxos diseaseD. Dowling-Meara Correct ChoiceE. Weber-CockayneClumped tonofilaments (keratin intermediate filaments) are seen in EB simplex subtype Dowling-Meara. Weber-Cockayne is a subtype of EB simplex with trauma-induced blistering on the soles ofthe feet and occasionally palms76) The most common cause of contact dermatitis in the United States is:A. NickelB. Hair dyesC. RubberD. ToxicodendronsCorrect ChoiceE. Nail lacquersThe most common cause of contact dermatitis in the USA are (in order of most to least common):toxicodendrons (poison ivy, oak, or sumac), nickel, fragrance, thimerosal, quarternium-15, 20
  21. 21. neomycin, formaldehyde and the formaldehyde-releasing preservatives, bacitracin, and rubbercompounds77) The antigen in linear IgA is:A. Laminin 5B. 97kDa part of BPAg2Correct ChoiceC. Alpha-6, beta integrinD. PlectinE. BPAg1The antigen in linear IgA and its variant, chronic bullous disease of childhood, is the 97kDa part ofBPAg2. BPAg1 is the antigen in bullous pemphigoid. Plectin is defective in EB simplex with musculardystrophy. Laminin 5 is defective in junctional EB and alpha 6, beta integrin is defective injunctionalEB with pyloric atresia.78) Bullous pemphigoid antigen 1 (BPAg1) is a member of this family:A. IntegrinB. SelectinC. Plakin Correct ChoiceD. Intermediate filamentE. CadherinThe plakin family includes desmoplakin I and II, BPAg1, envoplakin, periplakin79) Which of the following is the most common cause of contact dermatitis due to a formaldehydereleasing preservative?A. ThimerosalB. ParaphenylenediamineC. Paraben mixD. Quaternium 15Correct ChoiceE. Imidazolidinyl ureaQuaternium 15 is the primary cause of contact dermatitis among formaldehy-releasingpreservatives. Other formaldehyde-releasing preservatives include imidazolidinyl urea, diazolidinylurea, DMDM hydantoin, Bronopol, Cyanobutane, Ethyleneurea melamine formaldehy resin (found inpermanent press clothing), and dimethylol dihydroxyethyleneurea. Paraben mix (#1 preservative intopicals), thimerosal (a type of mercurial antiseptic), and paraphenylenediamine (hair dye) are non-formaldehyde releasing preservatives80) Bullous diabeticorum typically presents on the:A. ChestB. GroinC. Arms 21
  22. 22. D. FaceE. LegsCorrect ChoiceBullous diabetocorum presents as tense blisters on the legs. They are typically non-inflammatoryand appear suddenly81) A 60 year old gentleman presents with a recurrent pustular eruption. Biopsy demonstratessubcorneal pustules with abundant neutrophils and a serum protein electrophoresis shows amonoclonal IgA gammopathy. The autoantigen responsible for this condition:A. PlakoglobinB. Desmoglein IC. Desmocollin ICorrect ChoiceD. Beta 4 integrinE. DesmoplakinSneddon-Wilkenson (subcorneal pustular dermatosis) is a variant of IgA pemphigus. Clinically,patients have pustules arranged in annular and serpiginous pattern on the abdomen, axilla, andgroin. The antigen is desmocollin 1 and 2. Treatment options include acitretin and dapsone82) The anchoring plaque is composed primarily of:A. PlectinB. ConnexinsC. Collagen IVCorrect ChoiceD. Collagen XVIIE. Collagen VIICollagen IV is located in the dermal matrix and forms the anchoring plaque. The anchoring plaqueserves to anchor the lamina densa to the dermis via collagens 1,3 & 5.83) Which type of epidermolysis bullosa has the greatest risk of developing squamous cellcarcinomas?A. Hallopeau-Siemens type of recessive dystrophic EBCorrect ChoiceB. HerlitzC. Dowling-MearaD. Weber-CockayneE. EB Simplex with muscular dystrophyDystrophic EB is due to a defectin collagen 7, leading to decreased or absent anchoring fibrils in thesublamina densa. The three types of dominant dystrophic EB include Hyperplastic cockayne-Touraine, Albopapuloid Pasini, and Barts. The Recessive form of dystrophic EB is also known asHallpeau Siemens and patients present at birth owith generalized bullae which lead to erosions andatrophic scarring, mitten deformities, flexion contractures, oral and esophageal scarring andstrictures and dysplastic teeth. There is an increased risk of squamous cell carcinomas84) Fecal isocoproporphyrin is seen in:A. Acute intermittent porphyria 22
  23. 23. B. CoproporphyriaC. Variegate porphyriaD. HarderoporphyriaE. Porphyria cutanea tarda Correct ChoiceFecal isocoproporhyrin is characteristic of porphyria cutanea tarda85) Herpes gestationis is most commonly associated with:A. Graves diseaseCorrect ChoiceB. LupusC. MultiparityD. Inflammatory bowel diseaseE. LymphomaHerpes gestationis (HG) typically occurs in the second or third trimester, and clinically presents asurticarial papules and plaques around the umbilicus which progress to involve the rest of the body.HG has been associated with Graves disease86) Pinus palustris is the source of:A. UreaB. D-limoneneC. QuinonesD. LactonesE. Abietic acid Correct ChoiceAbietic acid is the allergenic component of rosin (colophony). D-limonene is found in tea tree oil.Primin is a quinone; it is found in the primrose (Primula obconica). Abietic acid is found in rosin87) Dermatitis herpetiformis is associated with:A. HLA-B27B. HLA-DQ1C. HLA-Cw6D. HLA-DR3 Correct ChoiceE. HLA-DR4HLA DR3 and DQ2 are associated with dermatitis herpetiformis. HLA B27 is associated with psoriasiswith spondylarthropathy while HLA Cw6 is associated with psoriasis88) Common causes of drug-induced linear IgA:A. PenicillinB. All of these answers are correctCorrect ChoiceC. Vancomycin 23
  24. 24. D. CaptoprilE. CephalosporinsLinear IgA disease that is induced by drugs is most commonly secondary to vancomycin. Otherimplicated drugs include other antibiotics and captopril89) Mutations in beta-catenin are most commonly associated with:A. Bullous pemphigoidB. Ectodermal dysplasia with skin fragilityC. PilomatricomasCorrect ChoiceD. Naxos diseaseE. Ocular cicatricial pemphigoidThe armadillo family of proteins constitute of group of proteins which function in cellular adhesion.These include beta catening, plakoglobin and plakophilins. Mutations in beta-catenin have beenassociated with some pilomatricdomas and colorectal carcinomas. Naxos disease has been linked toa mutation in plakoglobin, while ectodermal dysplasia with skin fragility has beenlinked to amutation in plakophilin 1. Ocular cicatricial pemphigoid is associated with antibodies to beta4-integrin90) This disease is inherited in an X-linked recessive manner:A. Chronic granulomatous disorder Correct ChoiceB. Dowling-MearaC. Mongomery’s syndromeD. Treacher-CollinsE. Job’s syndromeChronic granulomatous disorder is inherited in an X-linked recessive manner, as is Wiskott-Aldrich.Job’s syndrome is autosomal dominant. Dowling-Meara is a subtype of EB simplex, with autosomaldominant inheritance. Mongomery’s syndrome is xanthoma disseminatum. Treacher Collinssyndrome is also known as mandibulo-facial-dysostosis91) The C-terminal domain of BPAg2 is targeted in:A. IgA pemphigusB. Pemphigoid gestationisC. Duhring’s diseaseD. Bullous pemphigoidE. Cicatricial pemphigoid Correct ChoiceThe C-terminal domain of BPAg2 is targeted in cicatricial pemphigoid. The NC16A domain of BPAg2is targeted in bullous pemphigoid92) Which pair is incorrect?A. Antabuse : thiuramB. Eyedrops : thimerosal 24
  25. 25. C. Ear drops : neomycinD. Theophylline : ethylenediamineE. Cobalamin : balsam Correct ChoiceCobalamin is Vitamin B12; cobalt is a component of Vitamin B12. Balsam of Peru is found infragrances93) Which pair is incorrect?A. Glyceryl thioglycolate : acid permanent waveB. Permethrin : chrysanthemumC. Wrinkle-resistance : formaldehydeD. Chewing gum : colophonyE. Parabens : artichokes Correct ChoiceWrinkle-resistant clothing is treated with formaldehyde. Chewing gum contains rosin (colophony).Parabens are preservatives. Artichokes are a member of the family Asteraceae (formerlyCompositae). Glyceryl thioglycolate and methylchloroisothiazolinone are found in acid permanentwave products. Permethrins are synthetic pyrethroids that are similar to pyrethrins derived from theAsteraceae family. Permethrins can cross-react with allergy to chrysanthemums94) Which of the following is LEAST LIKELY to cross react with Toxicodendron plant dermatitis?A. Japanese lacquer treeB. Mango rindC. KiwiCorrect ChoiceD. Cashew nutE. Gingko treeThe Toxicodendron group of plants is the #1 cause of contact dermatitis in North America. Thisgroup of plants includes poison ivy, poison oak, and poison sumac. Because the Toxicodendronplants belong to the Anacardiaceae family, cross reactions can occur with related plants andsubstances such as braqzilian pepper, cashew nut, cashew oil, gingkgo tree, indian marking nut,Japanese lacquer tree, mango, and Rengas tree. Kiwi can cross react with patients who are latex-allergic95) This medicine causes degranulation of mast cellsA. All of these answers are correctCorrect ChoiceB. opiatesC. polymixin BD. ASAE. NSAIDsMast cell degranulators include NSAIDs, ASA, opiates, polymixin B, radiocontrast, tubocurarine,succinylcholine, and others96) The rate limiting step in the porphyria pathway is mediated by the enzyme: 25
  26. 26. A. Porphobilinogen deaminaseB. ALA synthaseCorrect ChoiceC. ALA dehydrataseD. FerrochetalaseE. Uroporphyrinogen decarboxylaseALA synthase mediates the first and rate-limiting step in the heme synthesis pathway. This stepoccurs in the mitochondria and allows for the conversion of Succinyl coA + glycine to deltaaminolevilinic acid97) At what level is the blister separation plane in linear IgA dermatosis?A. Suprabasal layerB. Lamina densaC. Basal layerD. Lamina lucidaCorrect ChoiceE. Granular layerThe cleavage in linear IgA dermatosis (LAD) typically occurs in the lamina lucida as the targetantigen is the 97 kD cleaved portion of bullous pemphigus antigen II (BPAgII). A variant of LAD mayseparate in the sublamina densa, with a target antigen of the type VII collagen in the anchoringfibrils. This condition may also be induced by ingestion of certain medications including vancomycin,lithium and diclofenac98) Which of the following forms of epidermolysis bullosa is autosomal recessive?A. Hyperplastic cockayne-touraineB. Dowling-MearaC. Weber-CockayneD. EB simplex with muscular dystrophyE. Junctional EB with pyloric atresiaCorrect ChoiceThe forms of junctional epidermolysis bullosa are inherited in an autosomal recessive fashion. Theseinclude Herlitz, non-Herlitz, JEB wityh pyloric atresia, JEB inversa, and GABEB. recessive dystrophicEB(Hallopeau-Siemens) is also a recessive subtype of dystrophic EB. EB simplex is typicallyinherited in an autosomal dominant fashion. Hyperplastic cockayne-touraine is a subtype ofdominant dystrophic EB99) Allergic contact dermatitis is characterized histologically by:A. ParakeratosisB. Psoriasiform dermatitisC. Lichenoid infiltrateD. GranulomaE. SpongiosisCorrect ChoiceSpongiosis refers to the accumulation of edema fluid between keratinocytes, in some casesprogressing to vesicle formation. The epidermis acquires a "spongy" appearance. Thishistopathologic pattern of inflammation is usually accompanied by an infiltrate of lymphocytes 26
  27. 27. within the epidermis and around superficial vessels. In addition to spongiosis, allergic contactdermatitis is typically accompanied by eosinophils100) Cicatricial pemphigoid can be induced by:A. AminoglycosidesB. CiprofloxacinC. VancomycinD. Clonidine Correct ChoiceE. BenzeneClonidine is a cause of drug-induced cicatricial pemphigoid. Other common causes includee sulfadrugs and thiol-containing drugs101) Patients with epidermolysis bullosa acquisita have:A. Antibodies to collagen VII Correct ChoiceB. A defect in plectinC. A defect in laminin 5D. Antibodies to collagen XVIIE. A defect in collagen XVIIEpidermolysis bullosa acquisita (EBA) classically presents in adulthood as noninflammatory trauma-induced bullae that heal with scarring, especially on the hands and feet. Histology shows asubepidermal blister (usually pauci-inflammatory); DIF shows linear IgG at the basememtmembrane; salt-split skin shows antibodies at the "floor". Patients hae antibodies to type VIIcollagen102) A 35 year-old dentist presents with tingling in his fingertips. What allergen is most likely tocause this dermatitis?A. Methyl methacrylateCorrect ChoiceB. Thiuram mixC. Ethylenediamine dihydrochlorideD. ParaphenylenediamineE. ColophonyMethyl methacrylate is found in synthetic resins, dentures, artificial, nail adhesives, and acrylic bonecement. This allergen may penetrate through the gloves to the fingertips and most often affects thefirst three fingers. In addition to dermatitis, it also causes a peripheral neuropathy103) Fiberglass dermatitis can be prevented by:A. WaterB. Talcum powder Correct ChoiceC. AlkaliD. Sodium chloride 27
  28. 28. E. Acetic acid 5%Talcum powder application causes fiberglass spicules to slide off skin104) Characteristic eosinophilic abscesses are seen in:A. Herpes gestationisB. Pemphigus vegetans Correct ChoiceC. Incontinentia pigmentiD. Paraneoplastic pemphigusE. Bullous drugEosinophilic abscesses with minimal to no spongiosis in a hyperplastic epidermis are characteristic ofpemphigus vegetans105) Antibodies to which antigen are most likely responsible for this disease?A. Desmoglein IB. Keratin 5C. Bullous pemphigoid antigen IICorrect ChoiceD. PlakoglobinE. DesmocollinThe clinical appearance of tense bullae and urticarial plaques is suggestive of bullous pemphigoid.Bullous pemphigoid antigen II is a transmembrane protein in the hemidesmosome. Antibodies tothis antigen are pathogenic in bullous pemphigoid106) Which of the following proteins is a 160kDa cadherin?A. EnvoplakinB. PlectinC. Desmoglein 3D. Desmoplakin IE. Desmoglein 1Correct ChoiceDesmogleins and desmocollins belong to the cadherin family of proteins, which are calcium-dependent adhesion molecules. Desmoglein I is a 160kDa cadherin, while Desmoglein 3 is a 130kDa cadherin. Desmoplakin, envoplakin, and plectin belong to the plakin family of adhesion proteins107) Antibodies in some forms of Stevens-Johnson bind to:A. Desmoglein 3B. Desmoplakin I Correct ChoiceC. Desmoglein 1D. PlakoglobinE. Desmoplakin I and desmoglein 3Antibodies against desmoplakin I and II have been found in Stevens-Johnson 28
  29. 29. 108) Which pair is not associated with allergic cross-reactivity?A. PABA : procaineB. Thimerosal : piroxicamC. Thiuram : sulfa drugs Correct ChoiceD. Balsam of Peru : cinnamonE. Ethylenediamine : hydroxyzineThiurams may cross-react with Antabuse (disulfiram109) Latex allergy can cross-react with all except:A. KiwiB. AvocadoC. BananaD. ChestnutE. Artichoke Correct ChoiceLatex allergy can cross-react with avocados, bananas, kiwis, chestnuts, and other foods. Artichokesare a member of the Asteraceae (formerly Compositae) family110) Patients with latex allergy are LEAST LIKELY to develop a reaction to:A. CashewCorrect ChoiceB. ChestnutC. AvocadoD. BananaE. KiwiAlthough rare, cross-reactivity in latex-allergic patients has been demonstrated to banana, kiwi,avocado, passion fruit, and chestnut. Cross-reaction to cashew has NOT been reported111) Which of the following is known as "prickly heat"?A. Miliaria rubraCorrect ChoiceB. Grovers diseaseC. Miliaria profundaD. Miliaria crystallinaE. Fox-Fordyce diseaseMiliaria are caused by occusion of ecrine sweat glands. Miliaria crystalina are clear minutesubcorneal vesicles with no inflammation. Miliaria rubra are red papules subepidermal vesicles withinflammation. Miliaria rubra is known as "prickly heat" as it presents after sweating, heat exposure,fever or occlusion. Miliaria profunda or pustulosa are red nodules or pustules with deeperinflammation. Fox-Fordyce disease is apocrine miliaria that is very pruritic and presents in axilla andanogenital area of women. Grovers disease is a papulovesicular eruption of the trunk that is pruritic 29
  30. 30. and can occur after sun exposure or in bedridden patients with occluded backs. HistologicallyGrovers disease presents with small foci of acantholytic dyskeratotic cells in the suprabasal region112) The best first line treatment for dermatitis herpetiformis is:A. PrednisoneB. ColchicineC. IVIGD. MethotrexateE. DapsoneCorrect ChoiceThe most effective drug for dermatitis herpetiformis is dapsonel. The dose varies between 50 and300mg daily. Side effects include hemolytic anemia, leukopenia, methemoglobinemia, and rarelyagranulocytosis or peripheral neuropathy. Sulfapyridine is also a very effective treatment fordermatitis herpetiformis113) Ocular cicatricial pemphigoid has antibodies against:A. KalininB. Gamma-cateninC. Beta4-integrin Correct ChoiceD. VinculinE. PeripherinOcular cicatricial pemphigoid (CP) has autoantibodies against beta4-integrin. CP associated withmalignancy has autoantibodies against epiligrin (laminin 5). CP with mucous membrane and skinfindings often has autoantibodies against BPAg2 30