Mimickers of Classical Urticaria: Cryopyrin-Associated Autoinflammatory Syndrome Presenting as Isolated Urticaria in an Infant

Abstract

A 5-month-old full-term girl presented as an outpatient with an urticarial rash, lymphocytosis, and eosinophilia after 2 previous hospitalizations for rhino/enterovirus infection. She exhibited a blanching, urticarial eruption with well-demarcated irregular borders and generalized distribution including the palms, soles, and face (Figure 1). The rash was not associated with cold, pruritus, bruising, or hyperpigmentation. The rash appeared within 48 hours of life and varied in severity, though never exhibited a period of complete resolution. The patient was otherwise well-appearing, with no history of fever, oral ulcers, purpura, arthropathy, lymphadenopathy, conjunctivitis, or dysmorphia. She initially had slow weight gain and intermittent bloody stools, both of which resolved with transition to extensively hydrolyzed formula at 1 month of age.