Flashcards in Skin Deck (352)
Pityriasis rubra pilaris: Histological differences from psoriasis (4).
Thick suprapapillary plates.
Short, thick rete pegs.
No neutrophils in the parakeratotic layer.
Polymorphous light eruption: Typical patient and season.
Young woman, summer.
Polymorphous light eruption: Anatomic distribution.
Upper chest, extensor surfaces of arms.
Polymorphous light eruption: Histology (3).
Normal or slightly spongiotic epidermis.
Marked papillary dermal edema.
Superficial and deep perivascular lymphocytes.
Pityriasis lichenoides: Histology (5).
Parakeratosis and scale-crust.
Spongiosis and necrotic keratinocytes.
Basal vacuolar change.
Papillary dermal edema with extravasated RBCs.
Lymphocytes obscure the DEJ and form superficial and deep perivascular infiltrates.
Pityriasis lichenoides et varioliformis acuta, ulceronecrotic variant: Histology.
There may be lymphocytic vasculitis.
Pityriasis lichenoides: Distinction from lymphomatoid papulosis.
The latter has atypical, CD30-positive lymphocytes.
Fixed drug eruption: Histology (4).
Basal vacuolar change that may progress into bullae.
Superficial and deep perivascular lymphocytes, neutrophils, eosinophils; sometimes also lichenoid.
Melanophages in the upper dermis.
Fixed drug eruption: Distinction from erythema multiforme.
Not always possible, but fixed drug eruption is more likely when there is a deeper infiltrate that includes neutrophils and eosinophils.
Fixed drug eruption: Instigators (3).
Lymphomatoid papulosis: Infiltrate.
Wedge-shaped and consists of neutrophils, eosinophils, plasma cells, and atypical lymphocytes.
Lymphomatoid papulosis: Morphology of atypical lymphocytes.
May resemble the cells of
Mycosis fungoides (cerebriform nuclei).
Hodgkin's lymphoma (Reed-Sternberg cells)
Anaplastic large-cell lymphoma.
Lymphomatoid papulosis: Feared outcome.
Progression to anaplastic large-cell lymphoma.
Secondary syphilis: Histology (5).
Parakeratosis with neutrophils.
Psoriasiform epidermal hyperplasia.
Basal vacuolar change.
Lichenoid mononuclear inflammation.
Lues maligna: Histology.
Thrombotic endarteritis of deep dermal vessels, leading to ischemic necrosis and ulceration.
Sweet's syndrome: Clinical triad.
Sweet's syndrome: Anatomic locations of rash.
Sweet's syndrome: Association (3).
AML or other myeloproliferative neoplasm.
Sweet's syndrome: Histology (3).
Dense infiltrate of neutrophils with nuclear dust but without leukocytoclastic vasculitis.
Papillary dermal edema.
Dilated blood vessels with plump endothelial cells and extravasated RBCs.
Pyoderma gangrenosum: Associations (4).
Inflammatory bowel disease.
Pyoderma gangrenosum: Inflammation.
Center of lesion: Neutrophils.
Border: Mixed infiltrate.
Pyoderma gangrenosum: Vasculitis.
Secondary vasculitis may arise in the necrotic, neutrophil-rich center.
Pyoderma gangrenosum in Crohn's disease.
May contain granulomas.
Eosinophilic cellulitis: Clinical presentation.
Red patches evolve into painful plaques; recurrent.
Eosinophilic cellulitis: Association with peripheral eosinophilia.
Seen in at least half of cases.
Eosinophilic cellulitis: Histology (3).
Dense, diffuse dermal infiltrate of eosinophils, sometimes with
− Flame figures.
− Necrobiosis with palisades of histiocytes.
Eosinophilic cellulitis: Possible causes (5).
Scabies: Name of mite.
Scabies: Most common sites of burrows (3).
Webs between fingers.