Bullous skin diseases

BULLOUS SKIN
DISEASES
Prepared By :- Dr Monther Fadel Nagi
Dermatology Resident

Pathogenesis
•
Pemphigus vulgaris is a serious autoimmune bullous
•
disorder caused by autoantibodies directed against
•
desmoglein 1 and desmoglein 3 . These molecules are
involved in the normal cohesion of keratinocytes, and
hence, the condition leads to large flaccid bullae that are
easily ruptured. The mouth is often involved. Rarely,
pemphigus vulgaris is triggered by drugs or foods
such as garlic and leeks.

Pathogenesis
•
Drug-Induced Pemphigus
•
• Captopril (common)
•
• D-Penicillamine (common)
•
• Amoxicillin (rare)
•
• Ampicillin (rare)
•
• Cephalosporins (rare)
•
• Penicillin (rare)
•
• Rifampin (rare)

Clinical Features
•
• The condition typically affects older adults (40–60
•
years old).
•
• Persons of Jewish or Hispanic heritage are more
•
often affected.
•
• The condition may be localized (often on the head
•
or trunk), or it may eventuate as a generalized eruption.
•
• Vesicles and bullae (up to several centimeters) arise
•
on normal or erythematous skin

•
• The Nikolsky sign may be present.
•
• Blisters rupture in 1 to 3 days, with a painful, raw,
•
erythematous base.
•
• Scaling and crusting of older lesions are common.
•
• Oral involvement is present in more than 90% of
•
patients during the course of the illness, and often it
is the initial site of the presentation.

Diagnosis
•
• A vesiculobullous disorder with marked mucosal
•
involvement suggests the diagnosis, especially if
•
the Nikolsky sign is present.
•
• A shave or punch biopsy from the edge of the lesion
should always be done.

Diagnosis
•
• DIF using perilesional skin may be performed on
•
a shave biopsy (preferred) or punch biopsy and
•
submitted in immunofluorescent transport media,
•
in saline (for up to 24–48 hours), or snap frozen.
•
• If a direct immunofluorescent medium is not available,
blood can be drawn in a red-top (serum
•
separator) tube and sent for indirect immunofluorescent
examination or ELISA testing.

Treatment
•
• First-line therapy is oral prednisone (0.5–1.0 mg/
•
kg per day) with a slow taper, using steroid-sparing
•
agents as the taper proceeds
•
.
•
• Pulse corticosteroids (250–1000 mg/day of
methylprednisolone sodium succinate) for 1 to 5 days
may be used for severe disease or for patients with a
•
poor response to oral prednisone.

Treatment
•
• Intravenous immunoglobulin (IVIG), 400 mg/kg per
day for 5 days, with the addition of cyclophosphamide
(100–150 mg/day) in severe cases, results in clearing in
80% of patients within 2 weeks.
•
• Methotrexate, azathioprine, rituximab, and
cyclophosphamide are steroid-sparing agents that
may be used in select cases.

Pathogenesis
•
Linear IgA bullous dermatosis (LABD) is a rare
autoimmune bullous condition in which IgA autoantibodies
are directed against a structural component of the
basement membrane zone between the epidermis and
dermis . Most cases are idiopathic, but a significant
number of cases are drug-induced. When it occurs in
children, it has also been
•
termed chronic bullous disease of childhood.

Pathogenesis
•
Drug-Induced Linear IgA Bullous Dermatosis
•
• Ampicillin-sulbactam (rare)
•
• Benazepril (rare)
•
• Carbamazepine (rare)
•
• Ceftriaxone-metronidazole (rare)
•
• Gemcitabine (rare)
•
• Naproxen (rare)
•
• Piroxicam (rare)
•
• Sulfadimethoxine (rare)
•
• Vancomycin (common)

Clinical Features
•
• LABD may affect children and adults.
•
• Both minute vesicles and large tense bullae may
•
be seen, sometimes on an erythematous base.
•
• Blisters may be arranged in groups or annular
configurations, sometimes likened to a string of pearls ,
or with sausage or beanlike shapes.

Clinical Features
•
• Lesions are often symmetrically distributed on
•
extensor surfaces, especially the back and neck.
•
• In severe cases, the blisters may be large and
generalized, mimicking those of TEN.
•
• Oral involvement is rather common and usually consists
of oral erosions and ulcerations.
•
• The blisters are usually pruritic.

Diagnosis
•
• The clinical presentation, particularly in a child,
•
can be persuasive, particularly because other
•
autoimmune disorders are relatively uncommon in
•
children.
•
• Annular configurations of blisters, arranged as a
•
string of pearls, strongly suggest the diagnosis.
•
• In adults, vancomycin use should prompt
consideration of drug-induced LABD.

Diagnosis
•
• A shave or punch biopsy is often useful in suggesting
•
the diagnosis, but other autoimmune blistering
•
diseases share similar histologic features.
•
• The diagnosis is established definitively via a punch
or shave biopsy of perilesional skin for DIF studies to
demonstrate a linear band of IgA autoantibodies.

Treatment
•
Oral prednisone is used initially for quick control,
•
usually at a dose of 0.5 to 1.0 mg/kg per day,
•
with tapering as the condition improves or as
•
steroid-sparing agents are added.
•
• Dapsone (25–100 mg PO qd) is the steroid-sparing
drug used most often.
•
• Sulfapyridine and colchicine are other steroid-sparing
agents that are used less often.

Pathogenesis
•
Pemphigus foliaceus (PF) is an uncommon autoimmune
•
bullous condition caused by immunoglobulin G (IgG)
autoantibodies directed against desmoglein 1,
•
a molecule involved in the normal cohesion of
keratinocytes.In this condition, the split occurs below the
•
cornified layer or in the superficial granular layer. This is
•
the same location as the split in bullous impetigo and
•
SSSS. PF can also be induced by some medications.

Pathogenesis
•
Causes of Drug-Induced Pemphigus Foliaceus
•
• Captopril (common)
•
• D-Penicillamine (common)
•
• Enalapril (rare)
•
• Sulfasalazine (rare)

Clinical Features
•
• Middle-aged and older adults are usually affected,
•
but, on occasion, children may be affected.
•
• There is a predilection for the head and trunk, but in
•
some cases it may involve the entire body surface
•
area, causing erythroderma.
•
• Primary lesions are often ruptured vesicles or, less
•
often, intact bullae that arise on normal or erythematous
skin .

Clinical Features
•
• In some cases, the blister may become cloudy or
•
even appear pustular.
•
• The Nikolsky sign is present in many cases
.
•
• Scaling and crusting are common, and, in some
•
cases, the condition may resemble dermatitis . Verrucous
lesions may even resemble a seborrheic keratosis.
•
• Drug-induced PF appears clinically identical to
idiopathic cases

Diagnosis
•
• Recurrent, superficial, often ruptured blisters, with a
background of scaling and crusting, are highly
suggestive of the diagnosis. There should be no oral
involvement.
•
• It is useful to culture the blister contents to exclude
bullous impetigo.
•
• A shave or punch biopsy, performed at the edge of
•
the lesion, is necessary to establish an acantholytic
•
blistering disorder; this is a cardinal feature of PF.

Diagnosis
•
• DIF of perilesional skin is the diagnostic method of
•
choice. This can be performed using a shave (preferred)
•
or punch biopsy. The tissue must be placed in
immunofluorescence transport media, normal saline (for
periods of <24–48 hours), or snap frozen.
•
• If a direct immunofluorescent medium is not readily
•
available, blood can be drawn in a red-top tube (serum
separator tube) and sent to a immunofluorescence
laboratory for indirect immunofluorescence or to a
reference laboratory for enzyme-linked immunosorbent
assay (ELISA) measurement of desmoglein antibodies.

Treatment
•
• First-line therapy is oral prednisone (0.5–1.0 mg/
•
kg per day) with a slow taper, using steroid-sparing
•
agents as the taper proceeds.
•
• Other medications and/or steroid-sparing agents
•
include methotrexate, azathioprine, dapsone,
cyclophosphamide, and rituximab.
•
• Any drug known to induce PF should be discontinued or
substituted with an unrelated agent.

Pathogenesis
•
Bullous pemphigoid (BP) is an autoimmune bullous
•
disease that usually occurs in elderly patients, although
•
any age group may be affected. The incidence of BP
•
has tripled in the past 10 years as the population of
•
the United States has aged. BP is mediated by IgG
•
autoantibodies (BPAg1 and BPAg2) directed against
•
portions of the hemidesmosome, a structure necessary
•
for normal attachment of the epidermis to the
•
dermis. This deposition results in an inflammatory
•
milieu that causes chemotaxis of inflammatory cells,
•
particularly eosinophils. It is unknown why these autoantibodies
•
develop.

Clinical Features
•
• Typically BP affects elderly patients, and it is more
•
common in patients with multiple comorbidities,
•
including neurologic disorders (e.g., dementia, Parkinson
disease).
•
• Urticarial plaques, or tense blisters, are common
Either or both forms of disease may be present in the
same patient.
•
• The Nikolsky sign is absent.

Clinical Features
•
• The most common location is the lower extremity,
although any skin surface may be affected.
•
• Older lesions demonstrate a raw, denuded base.
•
• Oral lesions are uncommon, although some studies
have reported that 20% of patients have mucosal lesions.

Diagnosis
•
• The occurrence of fixed urticarial lesions and tense
bullae is suggestive, especially in an elderly patient.
•
• Some bullous drug eruptions mimic BP, clinically
and histologically, and a careful drug history must be
taken.
•
• A biopsy (shave, punch, or small excision) of an
•
early urticarial lesion, or a new blister, is useful to
•
establish the diagnosis.

Diagnosis
•
• DIF is also useful to establish the diagnosis; this
•
requires a biopsy from perilesional skin (≈0.5–1 cm
•
away from a blister). This specimen needs to be
•
placed in immunofluorescent transport medium, in
•
normal saline (for 24–48 hours), or snap frozen.
•
• DIF studies demonstrate IgG and/or complement
•
component C3 deposited in a linear fashion at the
•
dermoepidermal junction.
•
• Indirect immunofluorescent studies have lesser
sensitivity (positive in 50%–80% of patients).

Treatment
•
• Those with a mild case and/or localized disease may
•
be managed with potent topical corticosteroids.
•
• Moderate to severe cases are managed first with
•
oral prednisone (≥0.5 mg/kg per day), with the
•
understanding that many elderly patients have
•
comorbidities (e.g., diabetes) that may complicate
•
Use.

Treatment
•
• After controlling the disease with oral corticosteroids,
•
steroid-sparing agents are generally used.
•
These may include doxycycline (100 mg PO bid)
•
with nicotinamide (500 mg PO qid), dapsone
•
(typical starting dose, 50 mg/day), and methotrexate
•
(5–15 mg as a weekly dose).
•
• Treatments used less often include azathioprine,
•
cyclophosphamide, mycophenolate, methotrexate,
•
chlorambucil, plasmapheresis, IV gamma globulin,
•
and rituximab.

Bullous Insect and Arthropod Reactions

Pathogenesis
•
Insects and arthropods can produce hypersensitivity
•
reactions in the skin. Saliva from the bite of the
•
organism (e.g., bedbugs, ticks) or feces (e.g., scybala
•
of scabies) may serve as an allergen. When allergen
•
exposure is limited, the host response is usually minor.
•
However, when the antigen exposure is more substantial,
•
or the host response is exaggerated, a vesiculobullous
•
reaction can ensue. Common causes of bullous
arthropod reactions include bedbugs (Cimexlectularius),
fleas , and chiggers.

Clinical Features
•
• Patients may or may not recall the insect or arthropod
bite.
•
• Lesions are often located on exposed areas of the body
and range from urticarial papules to bullae.
•
• Lesions may be solitary or multiple, and lesions can
•
be grouped, especially in bedbug bites.
•
• The blister may be unilocular or multilocular on an
•
erythematous base .

Clinical Features
•
• Bedbug bites occur most often on parts of the
•
body exposed during sleep (face, neck, hands, and
•
arms), and bites are often arranged in linear
configurations (so-called breakfast, lunch, and dinner
•
arrangement).
•
• Bullous insect and arthropod bite reactions are
•
nearly always intensely pruritic, except for blistering
•
reactions caused by cutaneous exposure to
•
members of the blister beetle family.

Diagnosis
•
• In some cases, the patient may bring in the offending
•
insect or arthropod
•
.
•
• Bedbugs are a particular problem of travelers, and a
travel history should be elicited.

Diagnosis
•
• According to a major national extermination
•
company, the top 10 cities for bedbugs includes
•
Detroit, Philadelphia, Cleveland, Los Angeles,
•
Dayton, Chicago, Columbus, Cincinnati, Dallas–
•
Fort Worth, and San Francisco.
•
• A shave or punch biopsy is not usually indicated
•
but, in problematic cases, the findings in a biopsy
•
can be supportive of the diagnosis.

Treatment
•
• Sedating antihistamines (e.g., diphenhydramine)
•
may be used at night for symptomatic relief and to
•
promote sleep.
•
• Potent or ultrapotent forms may be used in a
•
directed manner for a limited duration.
•
• Oral antibiotics may be appropriate if a secondary
•
bacterial infection is suspected.
•
• Depending on the clinical situation, other treatments
•
might include repellants, removal of pets or wildlife
•
(e.g., an abandoned bird’s nest near a bedroom
•
window), and/or professional extermination.

Introduction
•
Blistering distal dactylitis is an uncommon bacterial
•
infection that causes superficial blisters on the
•
distal fingers of young children. In reality, it is simply
•
bullous impetigo of acral skin; however, because of
•
the thick stratum corneum on the hands, the blisters
•
are tense. It is a distinctive disorder that presents in
•
acute fashion. It is caused most often by β-hemolytic
•
strains of Streptococcus pyogenes and less often by
•
S. aureus.

Clinical Features
•
• Characteristically, the condition affects children and,
•
less often, adolescents. Adults are rarely affected,
•
with most adult cases occurring in those who are
•
immunocompromised.
•
• Occasionally, classic impetigo may also be present
•
elsewhere .

Clinical Features
•
• The disorder yields rapidly evolving tense and
•
painful bullae on the anterior fat pads of the distal
•
fingertips . Older lesions may become crusted.
•
• Less often, the bullae extend to involve the lateral
and proximal nail folds.

Diagnosis
•
• The clinical presentation is suggestive of blistering
•
distal dactylitis, but the differential diagnosis
•
includes traumatic blisters, thermal and chemical burns,
and herpetic whitlow (herpes simplex infection
•
of the finger).
•
•The blisters of distal dactylitis are typically unilocular,

Diagnosis
•
whereas the blisters of herpetic whitlow are usually
•
multilocular; this is an important diagnostic clue.
•
• In an urgent care or office setting, the blisters can
•
be aspirated, with Gram staining performed on
•
the fluid and with abundant gram-positive cocci
•
apparent.
•
• The aspirate can be cultured with antibiotic sensitivities
used to guide management.

Treatment
•
• Tense blisters may be drained, but there is no
evidence
•
that this speeds recovery.
•
• Dicloxacillin at a dose of 3.125 to 6.25 mg/kg may
•
be used for children weighing less than 40 kg.
•
• Alternative treatments include cephalexin,
erythromycin, or another oral antibiotic that covers
streptococcal and staphylococcal infection.
•
• Because of the thickness of the blister roof and
•
frequent presence of β-hemolytic strains of S. pyogenes,
•
topical antibiotics, at least as solo therapy,
•
are not recommended.

Staphylococcal Scalded Skin Syndrome
(SSSS)

Pathogenesis
•
Staphylococcal scalded skin syndrome (Ritter; SSSS)
is caused by infection with group II (often phage group 71)
S. aureus. Blisters are caused by exfoliative toxins
elaborated by the bacteria that lyse an attachment
molecule (desmoglein 1) located between
keratinocytes. The result is a superficial split in the
epidermis in the area of the granular layer. It is thought
that infants and young children are more susceptible
because immature kidney function does not clear the
toxins. This is the same reason why an increased
incidence of SSSS is observed in adults with renal
disease. Increased susceptibility in immunocompromised
adults is poorly understood but may be due to impaired
neutralization of the toxin.

Pathogenesis
•
Nikolsky Sign
•
The Nikolsky sign refers to the production or extension of
a blister by lateral or rotating pressure on the epidermis
with a finger or a pencil. It is usually
•
associated with the following diseases:
•
• Pemphigus vulgaris
•
• Staphylococcal scalded skin syndrome
•
• Toxic epidermal necrolysis

Clinical Features
•
• The condition occurs most often in neonates and
•
young children (<5 years).
•
• The primary site of infection is often unapparent but
•
a prodrome of fever, malaise, lethargy, and irritability
•
is often observed.
•
• In children and neonates, the disease often begins
•
in the perioral region and on the neck, axillae, and
groin .
•
• Early lesions are tender and erythematous and
•
manifest variable edema, with superficial bullae and
•
skin fissuring.

Clinical Features
•
• Blisters are fragile, and sloughing leaves shallow
•
bullae, with a moist erythematous surface
•
• The Nikolsky sign is often present .
•
• Adults who experience SSSS frequently have
•
impaired renal function or are immunocompromised
•
and may also develop a staphylococcal cellulitis.
•
• Mucosal sites are rarely involved.

Diagnosis
•
• The clinical presentation is usually diagnostic in
•
neonates, infants, and children.
•
• Because the process is caused by a systemic toxin,
•
Gram staining and cultures of blister cavity fluid are
•
negative, in contrast to bullous impetigo.
•
• The diagnosis may be suggested on biopsy, with
•
a cleavage plane immediately below the granular
•
layer, but a biopsy is not usually required. The histologic
findings of pemphigus foliaceus overlap.

Treatment
•
• Older infants and young children who are able to
•
eat and drink, and who are with limited cutaneous
•
disease, can be treated with oral antibiotics sufficient
•
to cover S. aureus and with local skin care.
•
• Neonates and children with more severe disease
•
may require admission for intravenous antistaphylococcal
•
antibiotics such as naficillin, oxacillin, vancomycin,
•
or linezolid.
•
• Bland emollients (white petrolatum) may be used to
•
decrease pain and promote re-epithelialization.
•
• NSAIDs and other drugs that impair renal function
•
should be avoided.

Pathogenesis
•
Fixed drug eruptions (FDEs) are reactions produced
•
by drugs—and rarely by foods—that are localized
•
(fixed) to one or more mucocutaneous sites. More
•
than 100 drugs have been documented to produce
•
this reaction (see box). The pathogenesis of FDE
•
remains unknown, but studies have suggested that
•
T and B cells are stimulated by the causative drug,
•
and skin damage is due to antibody-dependent cell
•
cytotoxicity.

Pathogenesis
•
Common Causes of Fixed Drug Eruption
•
• Acetaminophen
•
• Antimalarials
•
• Barbiturates
•
• Fluoroquinolones
•
• Nonsteroidal antiinflammatory drug (NSAIDs)
•
• Penicillins
•
• Phenolphthalein
•
• Tetracyclines (class effect)
•
• Trimethoprim-sulfamethoxazole

Clinical Features
•
• An initial episode occurs 1 to 2 weeks after drug
•
exposure, but subsequent exposures can trigger an
•
effect within hours.
•
• Usually, only one site is affected in a first episode,
•
but subsequent episodes can involve the initial site
•
and one or more additional sites.

Clinical Features
•
• The primary lesion is an erythematous macule that
•
rapidly becomes an erythematous plaque.
•
• The erythema may subside or the lesion may
•
become bullous or ulcerated .
•
•The lesion resolves with residual hyperpigmentation.
•
• The face and male genitalia are the sites affected
•
most often.

Diagnosis
•
• The diagnosis is usually established on clinical grounds,
with the presentation of one or more discrete bullous
lesions, following ingestion of a drug. The diagnosis is
further established if a history reveals that this same site has
been involved in other reactions precipitated by the same drug.
•
• Rare cases may require a drug challenge or a 3- or 4-mm
punch biopsy. The histologic findings are not usually specific for
only FDE but can strongly suggest the diagnosis.
•
• Because FDE is common on the male genitalia, and
doxycycline is a drug used for a variety of sexually transmitted
diseases but can cause FDE, it is often important to establish
precisely when an ulceration of the penis began relative to the
use of doxycycline.

Treatment
•
• The implicated drug needs to be discontinued
•
immediately because the lesions will typically progress
•
to ulceration if the drug continues to be administered.
•
• Topical corticosteroids, when applied early in the
•
course of the reaction, will shorten the duration of
•
the inflammatory phase. The strength of the steroid
•
should be adjusted to the affected skin.

Pathogenesis
•
Stevens-Johnson syndrome (SJS), sometimes referred
•
to as erythema multiforme major, is a hypersensitivity
•
process usually caused by drugs, including antiepileptics,
•
antibiotics, and NSAIDs, and sometimes by infections
•
(e.g., HSV, Mycoplasma). The precise nosology
•
of SJS is controversial, with some authorities considering
•
it a disorder sui generis and others considering
•
it on a spectrum with toxic epidermal necrolysis (TEN).
•
This latter viewpoint has prevailed in recent years.
•
Classic SJS is defined as a vesiculobullous disorder
•
with targetoid lesions that affects at least two mucosal
•
surfaces.

Clinical Features
•
• SJS may affect persons of any age.
•
• Clinical lesions develop about 1 to 3 weeks after
•
ingestion of a causative drug or after a causative
•
infection, although sometimes SJS may occur
•
within a few days if it is a recurrent episode.
•
• Patients often demonstrate a prodrome of fever,
•
malaise, and myalgias.
•
• Cutaneous lesions resemble targetoid lesions of
•
erythema multiforme minor and may become bullous .

Clinical Features
•
• Lesions may involve the following:
•
– <10% of body surface area—considered classic
•
SJS
•
– 10% to 30% of body surface area—considered
•
SJS-TEN overlap
•
– >30% body surface area—often considered
•
simply as TEN
•
• Lesions are often painful and/or may produce a
•
burning sensation.
•
• Older bullous lesions may rupture or collapse, with
•
the epidermis shed, yielding superficial ulcers.
•
• The ocular mucosa, lips, oral mucosa , anogenital mucosa , and
lung mucosa
•
• Lesions may occur in sites of trauma (Koebner or
•
isomorphic phenomena).

Diagnosis
•
• The classic presentation of admixed bullous lesions,
•
atypical bullous targetoid lesions, and involvement
•
of at least two mucosal surfaces is sufficient for
•
establishing the diagnosis.
•
• A history of new medications within the past 3
•
weeks, or an infection, especially with Mycoplasma,
•
supports the diagnosis.
•
• Biopsies should be performed for standard H&E
•
examination and for DIF studies to exclude autoimmune
•
bullous conditions that can mimic SJS
•
(e.g., paraneoplastic pemphigus).

Treatment
•
• All patients should be hospitalized for supportive
•
therapy to include IV hydration, a controlled diet,
•
thermoregulation, pain control, and mouth rinses
•
and emollients.
•
• Potentially causative drugs must be discontinued as
•
soon as possible.
•
• Cases associated with possible recurrent HSV
•
infection may be treated with antivirals; cases of
•
suspected Mycoplasma pneumonia should be
•
treated with antibiotics.
•
• Use of oral corticosteroids in bullous erythema multiforme
•
is controversial, but most evidence suggests
•
that high-dose, short-duration steroid regimens
•
may be used early in the disease course.

Pathogenesis
•
TEN is a life-threatening, severe hypersensitivity
reaction to a drug (most common), infection or, rarely,
an immunization and represents a dermatologic
emergency.Many authorities consider it to be a severe
•
variant of Stevens-Johnson syndrome (see previous
•
section). For some drugs, there is evidence of a
•
genetic predisposition to develop TEN.

Pathogenesis
•
Common Causes of Toxic Epidermal Necrolysis
•
• Drugs
•
• Allopurinol
•
• Barbiturates
•
• Hydantoin
•
• NSAIDs
•
• Penicillins
•
• Sulfonamides
•
• Immunizations
•
• Infections
•
• Herpes simplex
•
• Mycoplasma
•
• Systemic fungal infections

Clinical Features
•
• TEN may affect any age group.
•
• Lesions develop about 1 to 3 weeks after a causative
•
drug (or infection), but some drug-induced cases may
develop quickly.
•
• Patients typically complain of skin pain and/or skin
•
burning and may develop erythema of the skin,
•
which rapidly becomes confluent, resembling a
•
sunburn.

Clinical Features
•
• By definition (, “Stevens-Johnson Syndrome”),
•
from 30% to 100% of the skin surface is involved.
•
• Fully developed lesions consist of sheets of necrotic
•
epidermis that shear easily, leaving an erythematous
•
raw base.
•
• The Nikolsky sign may be present, where the skin
•
will denude with lateral pressure.
•
• The ocular mucosa, lips, oral mucosa, anogenital
•
mucosa, and sinopulmonary epithelium may be
•
involved.

Diagnosis
•
• The classic presentation of painful erythema, resembling
severe sunburn, that easily denudes and occurs after ingestion
of a new medication, is strongly suggestive of the diagnosis.
•
• A positive Nikolsky sign is also strongly supportive
•
of the diagnosis .
•
• All cases should be biopsied for H&E and direct
immunofluorescence because this clinical pattern maybe
mimicked by other severe bullous disorders, such as
pemphigus, paraneoplastic pemphigus, and drug-induced,
linear, IgA bullous dermatosis.
•
• All patients should have a complete blood count (CBC) and
comprehensive metabolic panels (to include kidney and liver
function).

Treatment
•
• All patients should be hospitalized, preferably in a burn
unit, for supportive therapy. This should include proper
hydration, a controlled diet, thermoregulation, mouth rinses,
eye care, analgesics, and
•
emollients.
•
• Immediately withdraw any potentially causative drugs.
•
• As the skin denudes, replacement with some form
•
of appropriate dressing should be considered.
•
• Prophylactic antibiotics are not used, but the threshold for
culture and starting antibiotics is low.
•
• Second-line and controversial therapies include IVIG,
cyclosporine, plasmapheresis, and systemic corticosteroids.
•
• There should be liberal ophthalmology consultation
•
for patients with any possible ocular involvement.

Hand, Foot, and Mouth Disease
•
.

Pathogenesis
•
Hand, foot, and mouth disease (HFMD) is an infection
•
caused chiefly by coxsackievirus group A viruses,
•
with the most common cause being A16. Less often,
•
the disease may be caused by coxsackievirus groups
•
A4, A5, A6, A7, A9, and A10, coxsackievirus groups
•
B1, B2, B3, and B5, or enterovirus 71. Transmission
•
is fecal-oral. HFMD tends to occur in miniepidemics
•
during the summer months.

Clinical Features
•
• Typically, young children are affected, but the virus
•
may also affect adolescents and adults on occasion.
•
• The incubation period is brief (3–6 days).
•
• A brief prodrome of low-grade fever, malaise,
•
anorexia, and abdominal pain may be present.
•
• Primary lesions are round to oval erythematous
•
papules, with central vesicles and a cloudy or opalescent
•
appearance.
•
• Lesions arise most often on the hands and feet . At other
anatomic sites, the primary lesions may simply be red
macules, with variable scale or crust.

Clinical Features
•
• The number of lesions varies widely, from only a few
•
to over 100.
•
• Although the hands and feet are most often involved,
•
other common sites include the anogenital area , buttocks,
and flexural areas.
•
• An enanthem may affect the buccal mucosa,
•
tongue, soft palate, or gingiva and is seen in about
•
90% of patients as round to oval erosions on an
•
erythematous base, which can be painful
•
• One or more nails can be shed (onychomadesis).
•
• Lymphadenopathy is present in about 20% of cases.
•
• Lesions resolve without scarring.

Diagnosis
•
• The clinical presentation of a young child (usually <4
•
years old) with low-grade fever and lesions on the
•
hands, feet, and oral mucosa is usually sufficient for
•
a presumptive diagnosis.
•
• Problematic or severe cases may be diagnosed
•
with viral cultures of the oral pharynx or the fluid
•
aspirated from vesicles. Material from these same
•
sites can also be tested by PCR-based modalities.

Treatment
•
• The disease is self-limited and only symptomatic,
•
and supportive treatments are used. There is no
•
specific antiviral therapy.

THANK YOU
DR MONTHER FADEL NAGI
DERMATOLOGY RESIDENT

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