Psoriasis-like lesions in a patient with familial Mediterranean fever.

Familial Mediterranean fever (FMF) is a rare hereditary autoinflammatory disorder that is caused by pyrin gene mutation associated with aberrance of the interleukin (IL)-1β pathway and characterized by recurrent, self-limiting attacks of fever and other inflammatory symptoms. We report a case of FMF with annular erythema and psoriasis-like lesions, the latter of which demonstrated parakeratosis with neutrophil microabscesses and mild inflammatory mononuclear cell infiltration in the upper dermis. Immunofluorescence staining showed IL-17-positive T-cells. Skin eruption with neutrophil migration in the epidermis may be provoked by T-helper 17 cell activation through the abnormal IL-1β cascade in FMF.