Hyper-eosinophilic syndrome: An uncommon cause of chronic abdominal pain in an elderly male

Hypereosinophilia is defined as an absolute eosinophil count of ≥1.5 × 109/L, and its presence with involvement of at least one organ system defines the hypereosinophilic syndrome. It may occur with parasitic infestation, connective tissue disorder or rarely in clonal disorders such as eosinophilic leucaemia. Organ systems that may be involved include the cardiovascular, central nervous, respiratory and gastrointestinal systems. In the latter, a wide spectrum of clinical presentation may be seen from trivial, to debilitating or rarely fatal. We report an elderly male with a history of bronchial asthma, obstructive sleep apnoea and food allergy who presented with chronic abdominal pain and weight loss. Abdominal examination and routine evaluation were essentially normal other than a peripheral hyper-eosinophilia. We witnessed a brisk and lasting response to an elimination diet and corticosteroids.