Eosinophilic cellulitis induced by subcutaneous administration of interferon-β

Eosinophilic cellulitis (EC) is described as erythematous plaques with perivascular and interstitial infiltration of eosinophils. EC is associated with various skin disorders, and occurs in adverse drug reactions to many medications (1). A previous report described a patient with EC who was found to have increased interleukin (IL)-5-producing circulating T cells (2), suggesting the co-existence of a signal transducers and activator of transcription (STAT) 6-mediated Th2 response. We describe here a case of EC induced by administration of interferon (IFN)-β.