A case of annular erythema of infancy accompanied by elevated tryptase.

Annular erythema of infancy (AEI) is characterized by self-limited eruptions of erythematous, annular to polycyclic patches and plaques, the etiology of which is thought to involve a hypersensitivity reaction to an unknown antigen. We present a case of AEI mistaken for systemic mastocytosis due to elevated serum tryptase. We were unable to find prior reports of an association between AEI and elevated tryptase in the literature.