Acute hemorrhagic edema of infancy (AHEI)
:is a leukocytoclastic vasculitis in infants and toddlers, usually younger than 2 years of age,and represents 2.5% to 7% of HSP cases.It is characterized by a purpuric/ecchymotic rash with pronounced edema, predominantly over the face, ears, and limbs . There is debate about whether this entity represents a mild form of HSP or is a separate entity, as IgA deposits are seen only in 10% to 35% of biopsy specimens. Most cases are triggered by an upper respiratory infection, but other viral or vaccine triggers have been implicated.Patients rarely have joint (~3%), gastrointestinal (~3%) or renal (~2.5%) involvement, although in one series, 33% of patients had systemic involvement.189 Systemic involvement is more common in older infants. Rare cases of severe involvement have been reported.198 Corticosteroids were used in approximately 4% of patients.AHEI has an excellent prognosis, with resolution without treatment usually within 10 to 21 days, although in one series the median resolution was as long as 10 months.
Science Direct 2016