A diffuse, nonpruritic, erythematous, macular rash developed in a 43-year-old man with the acquired immunodeficiency syndrome (AIDS) and a CD4+ cell count of 22 per cubic millimeter. Initially, the rash was attributed to a drug eruption (due to either phenobarbital or ciprofloxacin). Approximately one week after the patient discontinued these medications, however, the rash progressed to form hyperkeratotic plaques on the chest, back, shoulders, elbows, and thighs. Panel A shows these hyperkeratotic plaque-like lesions in the shoulder region, where marked fissuring developed. What is the diagnosis?
a) Allergic Dermatitis
b) Urticaria
c) Cutaneous drug eruption
d) Norwegian Scabies
Answer is d) Norwegian Scabies
Skin scrapings from multiple body sites revealed abundant scabies mites. Panel B shows a single scabies mite, Sarcoptes scabiei (x 1100). The patient was treated with five applications of 5 percent permethrin cream over a two-week period, and the skin lesions resolved completely.
