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21 Cards in this Set
- Front
- Back
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Define Interface Dermatitis
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Group of Diseases with:
-Basal layer vacuolization -Necrotic keratinocytes (Broadly Sub-categorized as lichenoid or vacuolar) |
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Vacuolar Interface Dermatitis:
Differential |
Erythema multiforme
Toxic epidermal necrolysis Graft-versus-host disease Lupus erythematosus, acute Dermatomyositis Lichen sclerosus Morbilliform drug eruption Radiation-induced dermatitis, subacute and chronic |
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Erythema multiforme: Clinical
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-Erythematous patches with dusky centers
-Target lesions -Three zones “bull’s eye” *Peripheral rim of erythema *Inner rim of pallor *Central red macule -Bullae and erosions -Symmetric lesions -Predilection for distal extremities but may be generalized -Self-limited but often recurrent |
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Erythema multiforme: Associated with...
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HSV, medications, mycoplasma pneumonia
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Erythema multiforme: Spectrum of disease severity
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-Erythema multiforme
-Stevens-Johnson syndrome (with mucosal and conjunctival involvement) -Toxic epidermal necrolysis (TEN) |
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Erythema multiforme: Histology
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-Basket-weave stratum corneum
-Normal epidermal thickness -Vacuolar alteration of basal zone -Necrotic keratinocytes may be individual or confluent with full thickness epidermal necrosis -Sparse superficial to mid dermal infiltrate -Generally lymphomononuclear; no or rare eosinophils |
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Toxic Epidermal Necrolysis: Common Drug Culprits
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Allopurinol
Amoxicillin Ampicillin NSAIDs Phenobarbital Phenytoin Sulfonamides |
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Acute Graft-versus-Host Disease:Histology
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-Widespread vacuolar degeneration with scattered necrotic keratinocytes
-Necrotic cells present within adnexal structures -Lymphocytic exocytosis with satellite cell necrosis and mild spongiosis -Dermal edema with dilated blood vessels -Pigmentary incontinence |
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Lupus Erythematosus, systemic: Clinical
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-Diffuse erythematous macules and patches
-May have alopecia -Photodistributed -Malar “butterfly” rash -Little or no scale -Eruption often evanescent -Often associated with fully developed systemic disease -Positive high titer ANA -Antibodies to double-stranded DNA |
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Systemic lupus erythematosus: Histology
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Vacuolar alteration of basal keratinocytes
Perivascular lymphocytic infiltrate May obscure dermal-epidermal junction Altered basement membrane Dermal mucin accumulation Direct IF: band-like staining pattern for IgG and IgM at DEJ (lesional and non-lesional, sun-exposed skin) |
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Direct IF Findings in Lupus
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band-like staining pattern for IgG and IgM at DEJ (lesional and non-lesional, sun-exposed skin)
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Type of Lupus that may not show interface
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Tumid Lupus (should have a lot of mucin)
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Dermatomyositis, three clinical components
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-Erythematous macules and plaques with photoaccentuation
-Inflammation of skeletal muscle -Malignant neoplasms |
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Dermatomyositis: Clinical
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Erythematous infiltrated plaques usually on the face but may be generalized
Often periorbital erythema with violaceous hue (heliotrope rash) Firm, slightly pitting edema of shoulders, arms, neck Poikiloderma Erythematous, slightly scaly, or poikilodermatous patches on shoulders (shawl sign) Flat topped papules with scale over knuckles (Gottron’s papules) Reddish purple scaling eruption over knuckles, knees, and elbows (Gottron’s sign) Telangiectasia on proximal fingernails, frayed cuticles Photosensitivity Calcinosis – especially juvenile form |
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Dermatomyositis without muscle findings is called...
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“dermatomyositis sine myositis”
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Dermatomyositis:Histology
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-Epidermal atrophy
-Vacuolar alteration of basal keratinocytes -Sparse superficial perivascular infiltrate -Lymphomononuclear -Abundant mucin in interstitial dermis -Telangiectasia |
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Lichen Sclerosus is often associated with...
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vitiligo, alopecia areata, or thyroid disease
(likely autoimmune phenomenon) |
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Lichen sclerosus:Histology
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-Hyperkeratosis
-Vacuolar alteration of basal keratinocytes -Edema, homogenization, or sclerosis of the superficial dermis -Patchy, band-like lymphocytic infiltrate below zone of altered collagen |
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Morbilliform Drug Eruption:Histology
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-Usually normal stratum corneum, may have focal parakeratosis
-Epidermis generally normal in thickness or slightly thinned -Subtle vacuolar change accompanied by mild spongiosis -Superficial perivascular and interstitial infiltrate -Generally includes eosinophils -Erythrocyte extravasation |
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Morbilliform Drug Eruption: Clinical
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Salmon-colored small papules with slight scale
May be polycyclic Trunk and extremities often involved first, sometimes with evolution to face Usually symmetric distribution Eruption clears following withdrawal of drug |
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Radiation-induced Dermatitis:Histology
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-Hyperkeratosis, parakeratosis, crust
-Vacuolar alteration of basal zone with squamatization -Sparse dermal infiltrate -Variable fibrosis / sclerosis of dermis -Bizarre fibroblasts -Telangiectasia |
