Annular and arcuate syphilis: an uncommon presentation of disseminated secondary syphilis.

Physicians should be aware of unusual presentations of syphilis. For dermatologists, the visual recognition of lesional morphology and distribution is a fundamental part of clinical evaluation, which dictates the workup and diagnosis. Secondary syphilis has a variety of presentations, the most common being a diffuse symmetrical papulosquamous eruption.

A man with erythematous nodules: what is the diagnosis? Lepromatous leprosy.

A 65-year-old man presented with an approximately 5-year history of cutaneous nodules of the arms and legs. In addition, physical examination revealed bilateral thickening of ulnar and tibial nerves, distal weakness with hallux extension and finger abduction, and distal hypoesthesia of the left hallux. Histopathological analysis of the skin biopsy specimen showed a dense inflammatory infiltrate in the hypodermis, characterized by vacuolated macrophages containing multiple organisms.