Skin Flashcards
(352 cards)
Vitiligo: Typically spared areas (2).
Scalp and eyelashes.
Dermatophytosis: The “sandwich sign”.
Fungal hyphae between the parakeratotic layer and the overlying orthokeratosis.
Urticarial vasculitis:
A. Clinical features (3).
B. Duration of urticaria.
A. Recurrent urticaria, arthralgia, abdominal pain.
B. More than 24 hours.
Urticarial vasculitis: Histology.
Leukocytoclastic vasculitis without significant fibrin in vascular walls.
Urticarial vasculitis: Useful adjunctive laboratory tests (2).
Complement studies (CH50, C1q-binding assays).
DFA: May show vascular deposits of complement, immunoglobulins, or fibrin.
Urticarial vasculitis: Clinical associations (3).
Infectious hepatitis.
Infectious mononucleosis.
Autoimmune diseases.
Telangiectasia macularis eruptiva perstans: Histologic differences from urticaria (2).
Mast cells rather than eosinophils.
No significant dermal edema.
Lichen planus: Microbiological association.
Hepatitis C.
Lichen planus: Anatomic predilection of lesions (3).
Flexor surfaces.
Lower back.
Glans penis.
Oral lichen planus: Histologic differences from lichen planus of skin (3).
Parakeratosis.
Less epidermal hyperplasia.
Frequent ulceration.
Lichenoid drug eruption: Histologic differences from lichen planus (2).
Parakeratosis.
Eosinophils (sometimes).
Lichen striatus:
A. Age group.
B. Clinical appearance.
A. Children.
B. Unilateral eruption on extremities, trunk, neck.
Lichen striatus: Histologic differences from lichen planus.
Inflammatory infiltrate deep in reticular dermis around hair follicles and sweat glands.
Lichen nitidus:
A. Age group.
B. Clinical appearance.
A. Children.
B. Small, flat-topped papules.
Lichen nitidus: Histologic differences from lichen planus (4).
“Ball-in-claw” infiltrate.
Focal parakeratosis.
Epidermal atrophy.
Many histiocytes.
Lichen planopilaris vs. alopecia areata: Histology (2).
Lichen planopilaris: Infiltrate at base of follicular bulb; scarring.
Alopecia areata: Infiltrate along infundibulum; usually no scarring.
Erythema multiforme:
A. Infectious cause.
B. Pharmacological cause.
A. HSV.
B. Sulfonamides.
Toxic epidermal necrolysis: Drugs that cause it (3).
Sulfonamides.
β-lactam antibiotics.
NSAIDs.
Erythema multiforme: Histological feature of late lesion.
Dermal melanophages.
Erythema multiforme: Immunofluorescence.
IgM and C3 in the walls of superficial dermal vessels.
Angioedema: Histology.
Extension of the edema into the subcutis.
Acute GVHD:
A. Timing.
B. Clinical triad.
A. Within 3 months after transplant.
B. Rash, diarrhea, liver dysfunction.
Acute GVHD: Grade I.
Vacuolar change in basement membrane.
Acute GVHD: Grade II.
Necrotic keratinocytes, satellite necrosis.