A Solitary Red Patch.

The article describes the case of a 25-year-old woman with type 2 diabetes mellitus who came to the emergency department for evaluation of a hyperpigmented lesion on the shin and was diagnosed to have necrobiosis lipoidica. Topics covered include the performance of punch biopsy of the lesion to confirm the diagnosis, the characteristic appearance of necrobiosis lipoidica, and treatment of the disease.