Equestrian perniosis: a report of 2 cases and a review of the literature.

Equestrian perniosis (EP) is a rare condition in which patients develop tender burning nodular plaques on their bilateral thighs after riding in the cold. These lesions tend to resolve rapidly with minimal exposure to cold, and wearing loose, layered warm clothing. Unlike acral perniosis, EP has no known systemic disease associations, although 2 reported cases did have elevated cold agglutinins. The histology of this disease is similar to perniosis; however, EP is distinct in that the perivascular lymphocytic infiltrate prominently involves the fat. In this case report, we discuss the clinical and histological findings in 2 cases of EP, including the first documented in a man.