Archer Dermatology USMLE step 3


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Archer Dermatology USMLE step 3

  1. 1. DERMATOLOGY Archer’s Online USMLE Reviews All Rights reserved
  2. 2. Dermatology <ul><li>Pityriasis versicolor </li></ul><ul><li>Scabies </li></ul><ul><li>Psoriasis </li></ul><ul><li>Rosacea ( Rhinopyoma) </li></ul><ul><li>Acne and treatment </li></ul><ul><li>Secondary syphilis – skin rash </li></ul><ul><li>Pemphigus vulgaris & Bullous pemphigoid </li></ul><ul><li>Impetigo </li></ul><ul><li>Lichen Planus </li></ul><ul><li>Warafarin / hepain skin necrosis </li></ul><ul><li>Malignant Melanoma </li></ul><ul><li>Squamous cell ca </li></ul><ul><li>Basal cell Ca </li></ul><ul><li>Contact Dermatitis </li></ul>
  3. 3. This adolescent boy complained of chronic and recurrent scaly white spots on his trunk for years.  The scaling cleared with topical selenium sulfide lotion but the pigment took 4 months to recover.
  4. 4. Pityriasis Versicolor <ul><li>Also called Tinea Versicolor  not a true dermatophyte infection.Etiology includes Pityrosporum orbiculare , Pityrosporum ovale </li></ul><ul><li>and Malassezia furfur (prior name for organisms above) </li></ul><ul><li>Charecterized by scaly macules with fine scale. They can be hyper/ hypo pigmented  “ do not tan in summer ”  involves trunks and proximal extremities </li></ul><ul><li>Diagnosis : is by KOH mount.  Spaghetti (hyphae) and meatball (yeast) appearance </li></ul><ul><li>Wood's Lamp may show irregular pale yellow fluorescence. </li></ul><ul><li>Differential Diagnosis : Vitiligo , Seborrheacdermatitis , Tinea Corporis & Pityriasis Rosea </li></ul><ul><li>Rx: Hypopigmentation resolves slowly after Treatment!! </li></ul><ul><li>First choice rx : Topical selenium sulfide 2.5% lotion daily for 7 days. Alternatively, can use ketoconozole 2% cream daily x 14 days </li></ul><ul><li>Second choice : systemic antifungal – ketoconozole, itraconozole, fluconozole </li></ul><ul><li>Recurrence rate is very high  consider repeat Rx prior to summer / discard or boil suspected clothing that might be harboring the fungus </li></ul>
  5. 5. What do u do about Acne? Advise to pts, medical management, exacerbating factors etc
  6. 6. Acne - Ask Pts to avoid These! <ul><li>Exacerbating factors to avoid </li></ul><ul><li>Medications that exacerbate acne </li></ul><ul><ul><li>Androgenic steroids (e.g. Danazol Testosterone ) </li></ul></ul><ul><ul><li>Corticosteroids </li></ul></ul><ul><ul><li>Lithium </li></ul></ul><ul><ul><li>Oral Contraceptives  If Acne, Change Oral Contraceptive  Increase Estrogen (50ug Ethinyl Estradiol minimum) and Decrease androgenic effects of Progestin ( switch to 3 rd generation) </li></ul></ul><ul><ul><li>Isoniazid </li></ul></ul><ul><ul><li>Phenytoin (Dilantin) – choose carbamazepine for seizure control in teenagers. </li></ul></ul><ul><li>Oil based Cosmetics  Cosmetics with Lanolin or petroleum jelly / Oil based shampoos or Sunscreen  Change cosmetics to water based products </li></ul><ul><li>Emotional Stress </li></ul><ul><li>Physical Pressure (acne mechanica)  Tight chinstrap , Helmet </li></ul><ul><li>Clear the Myths </li></ul><ul><li>Foods DO NOT worsen acne  Pizza , Nuts , Sweets , Chocolate  nope, they don’t have anything to do with acne </li></ul><ul><li>Acne is not a result of poor hygiene </li></ul><ul><ul><li>Constant washing does not improve acne  Limit washing face to 2-3 times per day </li></ul></ul><ul><ul><li>Scrubbing dries and irritates skin further </li></ul></ul>
  7. 7. Moderate Acne Vulgaris Management <ul><li>Indications  moderate Acne vulgaris, Comedonal Acne vulgaris </li></ul><ul><li>1: OTC topical medications for 6 weeks eg: Topical Benzoyl Peroxide gel </li></ul><ul><li>If fails, </li></ul><ul><li>2: Comedolytics and Topical Antibiotics for 6 weeks </li></ul><ul><li>When there is comedonal acne, always Start Comedolytic (discontinue Benzoyl Peroxide) </li></ul><ul><ul><li>First-line options  Topical Tretinoin  Warn regarding redness and irritation/ contraception </li></ul></ul><ul><li>Consider adding a topical antibiotic </li></ul><ul><ul><li>Topical Erythromycin or Clindamycin </li></ul></ul>
  8. 8. Severe Acne Vulgaris <ul><li>Includes Moderate to severe Acne Vulgaris & Nodular, pustular, or cystic Acne Vulgaris </li></ul><ul><li>RX: Start Comedolytic ( Retin A) & topical antibiotic as above. Also start oral antibiotic  first line tetracycline/ erythromycin. Second line are doxycycline, bactrim </li></ul><ul><li>In very severe cases ( nodulocystic acne)  maximal medical therapy ( here side effects are high ) </li></ul><ul><li>Antiandrogens : spironolactone </li></ul><ul><li>Isotretinoin 1mg/kg/d for 20 weeks  extremely teratogenic. Be aware to monitor liver function tests and triglycerides </li></ul>
  9. 9. Isotretinoin ( Accutane) <ul><li>Indicated in Refractory acne vulgaris/ Nodulo cystic Acne </li></ul><ul><li>Adverse Effects </li></ul><ul><li>Very Teratogenic (even 1 pill)  Needs two forms Contraception while taking , Counsel extensively before use </li></ul><ul><li>Cheilitis , Dry or chapped skin ,Dry nose and eyes </li></ul><ul><li>Elevated serum Triglycerides (25%) </li></ul><ul><li>Arthralgias and Myalgias </li></ul><ul><li>Elevated liver transaminases </li></ul><ul><li>Peeling of palms and soles (5%) </li></ul><ul><li>Intracranial Hypertension </li></ul><ul><li>Night blindness </li></ul>
  10. 10. Isotretinoin <ul><li>Monitoring </li></ul><ul><li>Check Liver transaminases & Triglycerides at baseline and every 2-4 weeks </li></ul><ul><li>System Manage Accutane Related Teratogenicity (SMART) - Accutane </li></ul><ul><ul><li>Only SMART registered members may prescribe Accutane </li></ul></ul><ul><ul><li>Prescription limited to 30 days </li></ul></ul><ul><ul><li>Mandates 2 forms of Birth Control </li></ul></ul><ul><ul><ul><li>Both forms started >1 month before Accutane and continue Contraception for 1 month after stopping </li></ul></ul></ul><ul><ul><ul><li>One form must be primary Contraception </li></ul></ul></ul><ul><ul><ul><ul><li>Tubal Ligation or partner's Vasectomy </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Intrauterine Device </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Oral Contraceptive </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Depo Provera, Norplant or similar </li></ul></ul></ul></ul><ul><ul><li>Mandatory urine pregnancy timing </li></ul></ul><ul><ul><ul><li>Initial urine Pregnancy Test and Urine Pregnancy Test immediately before Accutane and Urine Pregnancy Test monthly at time of refill </li></ul></ul></ul><ul><ul><li>Prescriptions must carry qualification sticker  Yellow Accutane Qualification Sticker ( to obtain the sticker the provider has to complete the best practices booklet) </li></ul></ul>
  11. 11. <ul><li>This 45-year-old woman developed erythema, papules, pustules, and telangiectasias on the cheeks and forehead. The eruptions worsened with by high ambient temperature, hot drink, alcohol, spicy foods. </li></ul><ul><li>What is this ? </li></ul><ul><li>Nodulo cystic acne </li></ul><ul><li>Acne Rosacea </li></ul><ul><li>Folliculitis </li></ul>
  12. 12. Acne rosacea <ul><li>Most common in 30 to 5o yrs of age </li></ul><ul><li>Precipitated by Sun Exposure, hot weather, and hot baths, Emotional stressors , Alcohol ,Hot drinks & Exercise </li></ul><ul><li>Symptoms : stinging pain with facial flushing </li></ul><ul><li>Signs : Affects middle third of face (forehead to chin) </li></ul><ul><ul><li>Stage 1: Initial presentation  Intermittent facial Flushing </li></ul></ul><ul><ul><li>Stage 2: Early vascular changes  Facial erythema , Telangiectasis , Eye changes ( conjunctivitis, dry eyes, keratitis) </li></ul></ul><ul><ul><li>Stage 3: Inflammatory changes  Papules, Sterile Pustules  Comedones are typically absent </li></ul></ul><ul><ul><li>Stage 4: Rhinophyma (Red bulbous nose)  More common in men , Thickening of facial skin (especially nose due to connective tissue hypertrophy & Sebaceous Gland hypertrophy ) </li></ul></ul><ul><li>TREATMENT </li></ul><ul><li>Avoid alcohol , prolonged heat exposure, hot liquids (coffee, tea), heavy cosmetics and Use sun screen regularly </li></ul><ul><li>Avoid provocative medications  Benzoyl Peroxide and Topical Corticosteroid </li></ul><ul><li>For Papular & Pustular Rosacea </li></ul><ul><ul><li>First choice  topical agents Metronidazole gel or Azelaic acid gel. Alternatively u can use clindamyicin gel or permethrin 5% cream </li></ul></ul><ul><ul><li>Oral antibiotics for 1 month and then taper dose  useful in rxng severe rosacea or ocular rosacea with blepharitis, keratitis  doxycycline 100 bid or erythromycin 250 bid. Because of the higher risk of adverse reactions associated with long-term use of oral antibiotics, topical therapy is usually preferred long-term </li></ul></ul><ul><ul><li>In refractory cases consider topical retinoic acid </li></ul></ul><ul><li>For Rhinopyoma  Early cases treat with antibiotics, Advanced cases – surgery </li></ul><ul><li>For Ocular Rosacea  Artificial tears and oral antibiotics are first choice </li></ul><ul><li>For vasomotor symptoms like facial flushing and erythema  u still use first choice antibiotics as above. For symptomatic relief you may add clonidine or propranolol </li></ul>
  13. 13. Acne Rosacea – D/D <ul><li>Differential Diagnosis </li></ul><ul><li>Late-onset Acne Vulgaris  Comedones present, No telangiectasis & No eye symptoms or signs </li></ul><ul><li>Steroid-induced Acne - Results from Corticosteroid use on face  Charecterized by occurrence after steroid use, lack of comedones and presence of Perioral dermatitis </li></ul><ul><li>Perioral Dermatitis </li></ul><ul><li>Systemic Lupus Erythematosu </li></ul><ul><li>Allergic Conjunctivitis </li></ul><ul><li>Seborrheic Dermatitis ( can affect the same areas  does not have pustules, but has a scale, does not have flushing) </li></ul><ul><li>Carcinoid Syndrome (severe facial Flushing) </li></ul>
  14. 14. Rosacea may be associated with enlargement of the nose from excess tissue, a condition known as rhinophyma  includes thickening of the skin and irregular surface nodules Rx Early cases  antibiotics Late cases  surgery
  15. 15. Alopecia Areata <ul><li>Non-scarring autoimmune Alopecia - Most common under age 30 </li></ul><ul><li>Types </li></ul><ul><li>Alopecia areata: Patches of Hair Loss </li></ul><ul><li>Alopeca totalis: Hair Loss over entire scalp </li></ul><ul><li>Alopecia universalis: Hair Loss over entire body </li></ul><ul><li>Signs  Well-demarcated oval patches of Hair Loss </li></ul><ul><li>Exclamation point hairs at edges of Hair Loss, Club shaped Hair Root, Thin proximal Hair Shafft, Normal caliber distal Hair Shaft </li></ul><ul><li>Lab Evaluation (Consider) </li></ul><ul><li>KOH Scraping of patch </li></ul><ul><li>Thyroid Stimulating Hormone (TSH) </li></ul><ul><li>Rapid Plasma Reagin (RPR) </li></ul><ul><li>CBC, ESR </li></ul><ul><li>Antinuclear Antibody (ANA) and Rheumatoid Factr (RF) </li></ul><ul><li>Differential Diagnosis  Other non-scarring Alopecia , Tinea Capitis </li></ul><ul><li>Associated Conditions </li></ul><ul><li>Atopic Dermatitis , Vitiligo , Thyroid disease and Pernicious Anemia </li></ul>
  16. 16. Alopecia areata - Rx <ul><li>Moderate Involvement (<50% of scalp involved)  DOC is Intralesional ( not topical) Triamcinolone. Spontaneous resolution occurs in most cases. </li></ul><ul><li>Adjunctive therapy  Apply Minoxidil 5% solution twice daily or Mid-potency Topical Corticosteroid (eg. Kenalog 0.1%) </li></ul><ul><li>Severe Involvement (>50% of scalp involved)  refer to dermatology, use combination therapy with intralesional kenalog + topical contact sensitizer. Contact sensitizers  minoxidil 5% with topical steroids or Anthralin </li></ul><ul><li>Prognosis: the following indicates poor prognosis </li></ul><ul><li>Disease duration > one year </li></ul><ul><li>Onset of Alopecia prior to Puberty </li></ul><ul><li>Family History of Alopecia areata </li></ul><ul><li>Atopic Patients </li></ul><ul><li>Down Syndrome </li></ul>
  17. 17. Topical Corticosteroids
  18. 18. Topical Steroids <ul><li>Corticosteroid Potency Selection </li></ul><ul><li>Low potency topical Corticosteroids </li></ul><ul><ul><li>Face , Groin , Intertriginous areas </li></ul></ul><ul><li>Mid-potency topical Corticosteroids </li></ul><ul><ul><li>Thin skin trunk areas </li></ul></ul><ul><ul><li>Extremity lesions </li></ul></ul><ul><li>High potency topical Corticosteroids ( clobetasol 0.05%) </li></ul><ul><ul><li>Thick skin trunk areas </li></ul></ul><ul><ul><li>Extremity lesions </li></ul></ul><ul><li>Very high or super-potent Corticosteroids </li></ul><ul><ul><li>Very thick-skinned areas </li></ul></ul><ul><ul><li>Palms and soles </li></ul></ul><ul><li>Adverse Effects of Topical Steroids </li></ul><ul><li>Percutaneous absorption </li></ul><ul><li>Skin atrophy </li></ul><ul><li>Steroid Acne </li></ul><ul><li>Rebound papular dermatitis after medium-high potency </li></ul><ul><ul><li>Avoid high potency steroid on genital or face </li></ul></ul><ul><li>Striae formation </li></ul><ul><li>Fluorinated CS are more effective but have high risk of side effects </li></ul>
  19. 19. Vitiligo
  20. 20. Koebner Phenomenon - vitilgo
  21. 21. Treatment - Vitiligo <ul><li>A. Localized Vitiligo (involving <20% of total body surface area ) </li></ul><ul><ul><li>Topical corticosteroids - first-line treatment in localized vitiligo  Start with medium potency CS ( betamethasone 0.1) </li></ul></ul><ul><ul><li>Calcipotriol can be used as adjunctive therapy but never as monotherapy. </li></ul></ul><ul><ul><li>Use tacrolimus, a topical T-cell immunomodulator (calcineurin inhibitor), as an alternative to topical steroids in the treatment of localized vitiligo. </li></ul></ul><ul><li>B. Wide spread vitiligo ( > 50% depigmentation) </li></ul><ul><li>- Consider complete depigmentation using monobenzone rather than repigmentation, especially if repigmentation therapies have failed. If monobenzone fails  laser repigmentation </li></ul>
  22. 22. Scabies
  23. 23. Scabies
  24. 24. Scabies - Clues <ul><li>Itching, particularly at night </li></ul><ul><li>Family members, friends, or relatives with unexplained pruritus or scabies </li></ul><ul><li>Recent visits to a nursing home, hospital, or day care center and the time interval between onset of pruritus and the visit </li></ul><ul><li>Look for: </li></ul><ul><li>Burrows </li></ul><ul><ul><li>Wavy, threadlike, grayish-white, skin elevations measuring 1 to 10 mm </li></ul></ul><ul><li>Excoriations , Vesicles , Indurated nodules , Eczematous dermatitis </li></ul><ul><li>Common sites : the interdigital webbing of the hands , Axillae , Waist </li></ul><ul><li>Feet , Buttocks , areola in women, scrotal area in men </li></ul><ul><li>Examine Skin scrapings from suspicious lesions  put KOH in burrow , scrape it and examine under microscope for mites or obtain skin biopsy from burrows for diagnosis </li></ul><ul><li>In a patient with generalized pruritis  If the diagnosis is uncertain, obtain a skin biopsy to look for mites and eggs within the stratum corneum of the epidermis along with a dermal inflammatory infiltrate. </li></ul>
  25. 25. Mineral Oil Scraping Under Light Microscope <ul><li>Shows fecal pellets (scybala) and eggs. These are diagnostic even without a live mite </li></ul>
  26. 26. Scabies in Nursing Home pts <ul><li>As commonly happens, this patient's scabies was misdiagnosed for many months as psoriasis </li></ul>
  27. 27. Scabies Drug therapy <ul><li>Choose one of the following agents:  Permethrin, Lindane, Topical malathion , Benzyl benzoate or Topical ivermectin </li></ul><ul><li>Oral therapy – alternative to topical Rx - Ivermectin </li></ul><ul><li>Apply the preparation overnight to the entire body surface, regardless of the location of the lesions. </li></ul><ul><li>Itching could persist for 2 weeks after successful treatment because the dead mite and its antigens gradually slough off with the dead skin layers  Reassure patients about this! </li></ul><ul><li>T reat all family members and close contacts, even if they are unaffected or asymptomatic, simultaneously  A symptomatic mite carriers in the household are very common and are the reason for recurrence </li></ul>
  28. 28. Lichen Planus <ul><li>White lacy WICKHAM STRIAE are your clue for diagnosis. </li></ul><ul><li>May have pruritic cutaneous Papules on body </li></ul><ul><li>No RX required as most forms are asymptomatic. </li></ul><ul><li>Erosive form of lichen planus can cause pain  Erosive form is treated with topical steroids. </li></ul><ul><li>Diagnosis </li></ul><ul><li>Biopsy lichenoid lesions! </li></ul>
  29. 29. Advise Pts – Lichen Planus <ul><li>Advise patients to avoid scratching cutaneous lesions and eating Irritant food ( sharp-edged, spicy, or acidic food ) as trauma can lead to spread of lesions ( Kobner phenomenon) </li></ul><ul><li>If pruritic papules are present, use oral antihistamines to reduce pruritus. </li></ul>
  30. 30. This patient has joint pains and scaly patch behind his ear. What is the most likely cause of his findings?
  31. 31. Psoriasis <ul><li>Plaques characterized by Scaling, erythema and induration. </li></ul><ul><ul><ul><ul><ul><li>Chronic plaque psoriasis : erythematous, thick plaques with silvery scale, can be found anywhere on the body. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Guttate Psoriasis : mostly seen on the trunk, multiple , small drop-like papules and plaques </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Erythrodermic Psoriasis  severe erythema, scaling involving most of the body surface / exfoliation of skin can occur leading to fluid loss and infections </li></ul></ul></ul></ul></ul><ul><li>Common areas affected  scalps, ears, nails, intertriginous folds and flexural surfaces. </li></ul><ul><li>Nail changes  pitting, thickening or yellowing </li></ul><ul><li>Joints  arthritis, tendonitis, dactylitis ( DIP joint inflammation, sausage shaped finger), “pencil-in cup” deformity on the x-ray ( occurs when the distal end of the bone becomes pointed appearing as if it had been sharpened and the surrounding articular surfaces become “saucerized” due to “Erosions”. Also, seen in RA ) </li></ul>
  32. 32. Psoriasis - Rx <ul><li>Localized plaques  topical corticosteroids. Can be alternated with anthralin, tar preperations, retinoids or topical vitamin D analogs. Never use systemic corticosteroids </li></ul><ul><li>Plaque or Guttate psoriasis involving more than 5% body area or in case of poor response to topical agents  use phototherapy. </li></ul><ul><li>Erythrodermic Psoriasis  refer to dermatologist STAT – it’s a dermatological emergency! </li></ul>
  33. 33. Atopic dermatitis <ul><li>Picture – on forearm </li></ul><ul><li>Rx </li></ul>
  34. 34. Tinea cruris + picture <ul><li>Test to diagnose ? – koh preperation </li></ul>
  35. 35. A 25 y/o man presents with the lesion shown on his lower lip. What is the treatment?
  36. 36. Herpes Labialis <ul><li>Caused by Herpes simplex Virus Type I. </li></ul><ul><li>Most people are asymptomatic but only few people have recurrent outbreaks. </li></ul><ul><li>Triggers for outbreak are cold weather, stress, trauma. </li></ul><ul><li>Rx </li></ul><ul><ul><ul><li>Topical Penciclovir as your first choice. </li></ul></ul></ul><ul><ul><ul><li>Recurrent severe cases can be treated with oral Acyclovir. </li></ul></ul></ul>
  37. 37. A healthy 20 year old female come with history of paroxysmal lip swelling.  In the past , her doctor tried solumedrol and benasdryl but they never seem to make it better.  She says the swelling comes and goes spontaneously.  She has had negative skin prick testing
  38. 38. Angioedema <ul><li>Angioedema is a skin reaction similar to hives or urticaria.  characterized by an abrupt and short-lived swelling of the skin and mucous membranes  Any body part may be affected but swelling most often occurs around the eyes and lips, In severe cases the upper respiratory tract and intestinal mucosa may also be affected.  Can be hereditary or acquired </li></ul><ul><li>Know about ACEI induced angioedema – no more ACEI or ARBs </li></ul><ul><li>Know thEe main differences b/w urticaria and Angioedema 1.Tissues involved: Angioedema Subcutaneous and submucosal surfaces(beneath the dermis). Urticaria involves only the epidermis (outer layer of skin) and dermis (inner layer of skin) 2.Organs affected: Angioedema involve skin and mucosa, particularly the eyelids and lips . Urticaria involves skin only 2.Duration: Angioedema is Transitory (usually lasts between 24-48 hours). Urticaria is transitory (usually lasts < 24 hours) 3. Physical signs: Angioedema involves red or skin coloured swellings occurring below the surface of the skin. Urticaria has Red patches and weals on the surface of skin 4. Symptoms: Angioedema may or may not be itchy. Often accompanied by pain and tenderness. Urticaria is usually associated with an itch -Pain and tenderness uncommon. </li></ul>
  39. 39. Hereditary Angioedema <ul><li>Hereditary Angioedema  occurs due to deficiency of c1 esterase inhibitor </li></ul><ul><li>Diagnosis of HAE  C1 inhibitor level is low, C4 level is low (C1-INH deficiency allows auto-activation of C1, with consumption of C4 and C2 ) </li></ul><ul><li>Rx depends on the type. </li></ul><ul><ul><ul><li>If it is hereditary you need to give C1 inhibitor concentrate. If C1 concentrate is not available, give FFP. Alternatively, you can use high dose steroids like Danazol. </li></ul></ul></ul><ul><ul><ul><li>If laryngeal edema/ stridor  intubate! </li></ul></ul></ul>
  40. 40. Genital Warts Only Pics Therapy – refer I.D Slides
  41. 41. Genital warts - The real HPV - Differentiate from Benign Lesions
  42. 42. Pearly Penile Papules - A benign Lesion at corona - do not confuse with Warts! – Reassure patients!
  43. 43. Fordyce Spots - vulva – These are Sebaceous glands - do not confuse with warts!
  44. 44. Scabies can occur in Genital Areas - Do not confuse with warts! <ul><li>Questions like this are common on Step 3. A genital scabies should not be confused with other conditions like warts, syphilis etc. Look for clues in the history carefully - such as itching especially in the nights , family members with similar problems. Also, look at other sites on body - finger webs etc for burrows which is typical of scabies. </li></ul><ul><li>Look at finger webs! Common site of involvement - scabies </li></ul>
  45. 45. Q. <ul><li>A 46-year-old fisherman and Vietnam veteran presented with a recurrent rash on his arms and legs and a painful, swollen area on his left leg of several days' duration. The rash had been a problem for about two years and was treated with several courses of antibiotics for cellulitis. The patient reported that for the past two years his skin had been prone to blister and tear with minor trauma and that at times his urine appeared to be dark reddish in color. On examination, he had a slight fever and an area of cellulitis on his left leg. His face was erythematous. On his hands, arms, and legs were vesicles and small bullae, some crusted lesions, and hypopigmented and hyperpigmented macules. What is the most important next step in diagnosis? </li></ul><ul><li>A. ANA </li></ul><ul><li>B. Rheumatoid factor </li></ul><ul><li>C. Skin biopsy </li></ul><ul><li>D. Hepatitis C serology </li></ul><ul><li>E. Hepatitis B serology </li></ul>
  46. 47. Porphyria Cutanea Tarda <ul><li>PCT is due to a defective enzyme (uroporphyrinogen decarboxylase) in liver . ( the enzyme is involved in hem synthesis) </li></ul><ul><li>Genetic predisposition present </li></ul><ul><li>PCT begins in mid-adult life especially after exposure to substances that increase the production of porphyrins (precursors of haem) in the liver. </li></ul><ul><ul><ul><li>alcohol </li></ul></ul></ul><ul><ul><ul><li>oestrogen e.g. oral contraceptive, hormone replacement or liver disease </li></ul></ul></ul><ul><ul><ul><li>polychlorinated aromatic hydrocarbons (e.g. dioxins) </li></ul></ul></ul><ul><ul><ul><li>iron overload, due to excessive intake (orally or by blood transfusion), viral infections (hepatitis) or chronic blood disorders such as thalassaemia (acquired haemochromatosis), or hereditary haemochromatosis </li></ul></ul></ul>
  47. 48. C/F and Rx <ul><li>Sores (erosions) following relatively minor injuries </li></ul><ul><li>Fluid filled blisters (vesicles and bullae) </li></ul><ul><li>Tiny cysts (milia) arising as the blisters heal </li></ul><ul><li>Increased sensitivity to the sun </li></ul><ul><li>Characteristically, the urine is darker than usual, with a reddish or tea-coloured hue </li></ul><ul><li>If asked on the exam, consider the diagnosis of Hepatitis C infection ( imp association) </li></ul><ul><li>DX – Elevated urinary porphyrins, wood’s light on urine gives marked fluorescence </li></ul><ul><li>RX </li></ul><ul><ul><ul><li>Avoid alcohol </li></ul></ul></ul><ul><ul><ul><li>Use tanning creams in sun and avoid sun in acute flare. </li></ul></ul></ul><ul><ul><ul><li>Discontinue estrogens </li></ul></ul></ul><ul><ul><ul><li>Therapeutic phlebotomy to reduce iron stores (this improves heme synthesis disturbed by ferroinhibition of UROD. ) </li></ul></ul></ul><ul><ul><ul><li>In patients in whom phlebotomy is not convenient or is contraindicated and in those who have relatively mild iron overload  use oral chloroquine phosphate (or ) hydroxychloroquine sulfate </li></ul></ul></ul>
  48. 49. Erythema Multiforme <ul><li>Target lesions </li></ul><ul><li>Etiology : drugs ( penicillamine, sulfa) , HSV </li></ul><ul><li>Rx the etiology – corticosteroids are not effective. </li></ul>
  49. 50. Erythema Nodosum <ul><li>Rx – NSAIDS </li></ul><ul><li>Good prognosis in sarcoidosis </li></ul><ul><li>Bad prognosis in ulcerative colitis </li></ul>
  50. 51. Actinic Keratoses <ul><li>Pre Malignant lesions for squamous cell carcinoma </li></ul><ul><li>Found more on sun exposed areas. </li></ul><ul><li>Flesh colored, red papules with whitish scale </li></ul><ul><li>Get biopsy </li></ul><ul><ul><ul><li>If lesion > 5mm </li></ul></ul></ul><ul><ul><ul><li>Rapidly growing lesions </li></ul></ul></ul><ul><ul><ul><li>Thick, indurated papules </li></ul></ul></ul><ul><ul><ul><li>Lesions that grow rapidly in size </li></ul></ul></ul><ul><li>Rx – If lesion looks suspicious for malignancy  excision is the choice. For all others, Rx with cryotherapy or curettage </li></ul><ul><li>If Actinic keratoses are numerous  use topical 5-Fluorouracil </li></ul>
  51. 52. Seborrheic Keratoses <ul><li>Stuck on appearacnce </li></ul><ul><li>Yellowish, waxy plaques </li></ul><ul><li>Benign lesions </li></ul>
  52. 53. Basal cell carcinoma <ul><ul><li>Pink pearly papule with central ulceration – usually on face </li></ul></ul><ul><ul><li>Get biopsy </li></ul></ul><ul><ul><li>Rx – MOHs micrographic surgery for BCC on face </li></ul></ul>
  53. 54. Contact Dermatitis <ul><li>Inflammatory skin reaction resulting from DIRECT contact with an offending agent. Two principal types: </li></ul><ul><ul><ul><li>Irritant Contact Dermatitis ( ICD) </li></ul></ul></ul><ul><ul><ul><li>Allergic Contact Deramatitis (ACD) </li></ul></ul></ul><ul><li>ICD : Occurs from direct injury to the skin by a specific irritant. </li></ul><ul><ul><ul><li>Acute ICD occurs immediately after exposure to the irritant ( acid, alkali) and is associated with burning sensation, bright red edematous skin and bullae/ vesicle formation. </li></ul></ul></ul><ul><ul><ul><li>Chronic ICD occurs from prolonged exposure to a mild irritant (soaps and prolonged exposure to water) . This presents initially as dryness which is followed by erythema and eventually, progress to lichenification, cracking and formation of painful fissures. Edema is minimal </li></ul></ul></ul><ul><li>ACD : Is strikingly different from ICD in the time of onset after exposure. ACD occurs only in those people that were previously sensitized to the substance. It is a delayed (cell-mediated, type IV) hypersensitivity reaction ( and presents within 24 to 72 hours after exposure to the allergen ) ( poison ivy, nickel , potassium dichromate). Associated with erythema, bullae formation and pruritis. Lasts for 3 to 4 weeks. </li></ul>
  54. 55. Contact Dermatitis <ul><li>Management : </li></ul><ul><ul><ul><li>First step is to identify and avoid the irritant. – MOST IMPORTANT STEP! </li></ul></ul></ul><ul><ul><ul><li>Symptomatic treatment : </li></ul></ul></ul><ul><ul><ul><ul><ul><li>Emollients ( petrolatum jelly) for chronic cases </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Wet compresses with an astringent such as Aluminium acetate  gives soothing effect and helps pruritis </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>H1 blockers (benadry) for erythema and itching </li></ul></ul></ul></ul></ul><ul><ul><ul><li>Drug of choice for treating contact dermatitis are Topical steroids eg: Triamcinolone acetate </li></ul></ul></ul><ul><ul><ul><li>For severe cases ( contact dermatitis involving more than 10% of total body surface area or associated with extensive bullae ) eg: Prednisone orally  use at least for 2 to 3 weeks with slow tapering. Very short course can lead to recurrence of the problem. </li></ul></ul></ul>
  55. 56. Subacute Contact Dermatitis from a mild irritant – like eg: Bacitracin in the first picture and wool clothing in fig.2 – Note the prolonged exposure must have led to dryness followed by erythema and lichenification <ul><li>Fig # 1 </li></ul><ul><li>Fig# 2 </li></ul>
  56. 57. Nickel Contact Dermatitis <ul><li>This boy presented with Itchy rash around the naval. Note the sharply defined borders of the lesion consistent with the contact area of the metal ( in this case, blue jeans button made of Nickel). Treatment is Topical steroid and avoidance of nickel . </li></ul>
  57. 58. Question <ul><li>A 10 y/o boy is brought by his mother for extensive rash on his lower extremities that started one day ago and has been worsening. There is no history of fever . The family just returned four days ago from a camping trip and the mother does not recall any exposure to ticks except that the boy stepped in to a bush while walking downhill. On examination, there is extensive erythema along with vesicles and bullae on the front and the back of bilateral lower extremities up until the level of the knees. The upper portion of the lower extremities is unaffected. The rest of the physical examination is normal. The best treatment for the management of this child’s condition is : </li></ul><ul><li>A. Topical triamcinolone </li></ul><ul><li>B. Prednisone orally </li></ul><ul><li>C. Ceftriaxone intra-muscular </li></ul><ul><li>D. Diphenhydramine </li></ul><ul><li>E. Observation </li></ul>
  58. 59. Ans. B <ul><li>Oral prednisone is the treatment of choice here since the boy has greater than 10% involvement of total body surface area and also, extensive bullae. </li></ul><ul><li>The lesions are too extensive for Topical steroid use. </li></ul><ul><li>Diphenhydramine may provide symptomatic relief but will not address the underlying pathology </li></ul>
  59. 60. Malignant Melanoma <ul><li>A 69-year-old woman was evaluated for an enlarging pigmented lesion of her right cheek. A malignant lentigo melanoma was clinically suspected. Two biopsies were performed with the help of dermoscopy to outline the borders of the lesion. Pathology revealed a lentigo maligna melanoma </li></ul>
  60. 61. RASHES <ul><li>All rashes – infectious </li></ul><ul><li>Maculopapular etc </li></ul>
  61. 62. IMAGES <ul><li>OPHTHALMIC - Fundus </li></ul><ul><li>DERM </li></ul><ul><li>Some CT/ MRI </li></ul>