The lesions of chickenpox progress from macule to vesicle ("dewdrop on a rose petal") and are not typically hemorrhagic or necrotic like the papules of PLEVA.
Leukocytoclastic vasculitis is characterized by palpable purpura, which are non-blanching, purpuric papules, whereas PLEVA lesions are papules that can become vesicular, hemorrhagic, and crusted.
DH presents with intensely itchy, grouped vesicles on extensor surfaces and lacks the hemorrhagic or necrotic features of PLEVA.
EM is characterized by classic target lesions, a different morphology than the varied papules of PLEVA.
Folliculitis consists of pustules centered on hair follicles, not the crusted, hemorrhagic papules of PLEVA.
Bites are pruritic papules on exposed skin, but they do not typically undergo the necrotic and ulcerative changes seen in PLEVA.
This is a drug-induced eruption of lichen planus-like papules, which are violaceous and flat-topped, not the crusted, varied papules of PLEVA.
This is the most important differential; LyP is a low-grade lymphoma with recurrent crops of papules that ulcerate and heal. It is histologically distinct (CD30+ cells) but can be clinically indistinguishable from PLEVA.
