Erythema multiforme after treatment with sorafenib.

Sorafenib, an oral chemotherapeutic agent used in the treatment of solid tumors, is associated with a variety of adverse cutaneous drug reactions in up to 90% of patients. Infrequently, delayed-type hypersensitivity reactions such as erythema multiforme occur. This case describes a child treated with sorafenib for a retrosternal desmoid tumor who developed widespread erythema multiforme across his extremities, trunk, face, and mucosal membranes.

A case of S-100-negative CD1a-positive indeterminate cell histiocytosis.

Histiocytoses are a group of rare disorders characterized by a proliferation of monocytes/macrophages and dendritic cells. We present a case of a 3-year-old girl with a diffuse papular eruption without systemic symptoms demonstrating a proliferation of strongly CD1a+ histiocytes, but negative for S-100 and langerin on histopathology. Systemic work-up including bone marrow biopsy was unremarkable, and the patient received a diagnosis of CD1a+ S- 100-indeterminate cell histiocytosis.