The combination of direct fluorescent-antibody testing of an eschar from the presumed site of inoculation and histopathological examination of papulovesicles for distinctive features represents an improved method of diagnosing rickettsialpox.

Recognition of this entity is important because pseudoverrucous papules and nodules may mimic more serious dermatoses and unnecessary workup may be initiated. Although this reaction involving perianal skin has not been reported previously, we believe it is not uncommon.

No abstract

Giant cell lichenoid dermatitis is a recently described dermatosis thought to be an unusual lichenoid drug eruption. It is characterized by a generalized, pruritic, papulosquamous eruption sparing palms, soles, face and mucous membranes. Histopathologic findings include areas of epidermal hyperplasia and atrophy with focal vacuolar alteration of the basal layer, exocytosis and cytoid body formation. The dermis contains a band-like, mononuclear cell infiltrate at the dermoepidermal junction with admixed eosinophils, plasma cells and large multinucleate cells. The histologic differential diagnosis includes infectious processes, sarcoidosis, lichen nitidus, lupus erythematosus and lichen planus. We report 3 patients with giant cell lichenoid dermatitis, one of whom was subsequently diagnosed as having sarcoidosis. Because giant cell lichenoid dermatitis may resemble sarcoidosis both clinically and histologically, and because cutaneous sarcoid is often associated with systemic involvement, the diagnosis of sarcoid should be strongly considered in patients with giant cell lichenoid dermatitis.