Erythema nodosum in an adolescent patient with cryopyrin-associated periodic syndrome.

Cryopyrin-associated periodic syndrome (CAPS) is a monogenetic auto-inflammatory disorder with systemic manifestations. Innate immune system aberrance is seen in both CAPS and erythema nodosum and this case may point to a previously unknown association. In pediatric patients with EN and systemic features, the possibility of underlying CAPS should be considered.