Ten patients presenting with a history of the acute onset of hand ischemia have undergone detailed clinical, immunologic, and arteriographic evaluation. The disease is characterized by the acute onset of hand ischemia proceeding to fingertip ulceration, in the absence of recognized systemic disease. None of the patients had any evidence of large artery obstruction. Arteriography showed diffuse obstruction of the palmar and digital arteries. No evidence was found in any patient of any systemic disease process associated with small artery obstruction. These patients are suspected of having a previously unreported variant of hypersensitivity angiitis. Patients are left with permanent obstruction of the palmar and digital arteries. Follow-up suggests the disease in non-recurrent and is characterized by progessive clinical improvement associated with the development of collateral circulation. Conservative management of the condition is recommended.