This condition occurs in patients with asthma or a history of allergy. It usually develops in middle age and affects men more commonly than it does women.
In many patients, the disease follows a phasic pattern. Initially, there is an increase in allergic manifestations, especially asthma, followed by eosinophilia and finally vasculitis. Fever, malaise and weight loss are common early manifestations. As the vasculitis develops, asthma may become less prominent.
Cutaneous findings include petechiae, purpura or ulcerations. Chest discomfort or shortness of breath may result from pulmonary lesions. Peripheral neuropathy, usually multiple mononeuropathies, is common.
Abdominal symptoms include diarrhoea, pain or a mass due to ischaemia or infarction of abdominal organs. Renal lesions tend to be less severe than in polyarteritis nodosa. Eosinophilic granulomatous involvement of the gastrointestinal and urinary tracts or prostate is a unique feature of this syndrome.