ABSTRACT
<p><b>OBJECTIVE</b>To study the clinical characteristics and pathogenesis of hematidrosis.</p><p><b>METHODS</b>Detailed clinical manifestations and natural history of a patient with hematidrosis were presented. A series of laboratory examinations were performed, and skin pathohistologic features and ultra microscopic structures were observed.</p><p><b>RESULTS</b>The episodes of skin bleeding occurred on any site of the body spontaneously and promptly. The skin surface bloody extravasation has identical cell components as that of peripheral blood. All the results of laboratory tests were normal except a positive Trousseau's test. Skin pathohistological study revealed some intradermal bleeding and emphraxised capillaries. No abnormality was found in sweat glands, hair follicles and sebaceous glands.</p><p><b>CONCLUSION</b>The pathological basis for hematidrosis might be a distinctive vasculitis.</p>