Acute purple and perplexing

Abstract

Introduction Acute haemorrhagic oedema of infancy (AHOI) is an infrequently reported vasculitis (leucocytoclastic) in children less than 3 years of age. It is generally preceded by a variety of infections or drug intake or immunisations. It is characterised by abrupt onset of fever, purpuric lesions and peripheral oedema of extremities and face that may be confused with other causes of purpura. We report 3 cases of AHOI to highlight the variable presentation and emphasise the benign course. Cases 1. A 12 months old male infant presented with a one day history of non-blanching rash on the legs, associated with preceding coryzal symptoms, pyrexia and persistent discharge from the left ear despite oral antibiotics. The rash was initially felt to be Henoch-Schonlein purpura (HSP). 2. A 13 months old female presented with itchy rash and intermittent fever with preceding history of coryzal symptoms. The initial diagnosis of erythema multiforme was revised as she developed a florid annular erythema and widespread purpura over the next twenty four hours. 3. A 3 year old male presented with an urticarial rash and pyrexia. He was managed conservatively as viral urticaria. The rash dramatically spread all over the body as purpura developed. He was treated with intravenous antibiotics for presumed meningococcal sepsis. However, the rash continued to evolve and he remained otherwise well. In all these cases urine analysis and blood pressure were normal and there was complete resolution of the skin lesions after one to two weeks. Conclusion AHOI should be considered in differential diagnosis for evaluation of the child with purpuric lesions. A confident clinical diagnosis may require the support of an experienced dermatologist and is usually possible without requiring a skin biopsy. Visceral involvement is rare and systemic corticosteroids are unnecessary due to spontaneous resolution. In our experience it is not as uncommon as some authors suggest. Familiarity with its variable clinical features is of value to the paediatrician and dermatologist seeing these children in the acute medical setting.