[Differential diagnoses of Raynaud's phenomenon].
Raynaud's phenomenon (RP) is characterized by repeated vasospastic attacks of the distal extremities induced by cold, humidity, vibrations or emotional stress. It typically presents a triphasic colour change from white (palor; vasoconstriction) to blue (cyanosis) and red (reactive hyperaemia). The symptoms are based on a primary RP in 90 %. Secondary RP is a symptom of an underlying disease. RP has to be distinguished from other colour changes of the distal extremities like acrocyanosis, erythromelalgia, perniosis and Chilblain-Lupus. Patients history, clinical examination, ANA, ESR/CRP and nailfold capillaroscopy are essential for the early diagnosis of an underlying disease. The initiation of angiologic tests is important in patients with digital ulcers, necrosis or gangrene. Important differential diagnoses in secondary RP are autoimmune rheumatic diseases like systemic sclerosis and systemic lupus erythematodes as well as vascular diseases like arterial occlusions and compression syndromes or concomitant medication (i. e. beta-blocker).