[Acute hemorrhagic edema of infancy]

In infants less than 2 years of age, acute hemorrhagic edema of infancy (AHEI) is characterized by the rapid onset of annular purpuric lesions associated with initially localized edemas affecting the extremities. This disorder is usually benign, without visceral involvement. Diagnosis is based on clinical examination, no specific laboratory findings exist and the histological examination of the lesions (which is unnecessary in the majority of cases) is most often nonspecific (sometimes patients have nonspecific leukocytoclastic vasculitis). Nosological status of AHEI remains unclear, but some reports suggest it is a clinical manifestation of rheumatoid purpura. Rhinopharyngeal episodes in the days before its onset have sometimes been reported, suggesting a viral cause. There is a net mismatch between patient's good general condition and the remarkable dissemination of the lesions. Infants monitoring must be rigorous in the first days, even though complications are exceptional (acute intussusception). Patients recover spontaneously within 12 days. Therapeutic management is based on accurate monitoring of the infant's general status. Fever, the extension of the purpuric lesions and, in particular, signs of impaired general condition may suggest the diagnosis of purpura fulminans. Another differential diagnosis is acute hemorrhagic or ecchymotic urticaria. We here report the case of a 3-month old infant with diffuse pseudoannular lesions within a context of apyrexy and preservation of patient's general condition. Patient's outcome was favorable without any treatment, confirming the diagnosis of AHEI.