[Significance of monitoring histamine serum levels, cryoglobulins and complement titers during cold tests in patients with cold allergy and Raynaud's phenomenon].

The aim of our investigations is to evaluate blood histamine, complement titer and cryoglobulins before and after cold stimulation (extremity water immersion test) in patients with cold urticaria and Raynaud phenomenon. In our investigations patients were put into five groups according to the following diagnoses: cold urticaria (40 patients), chronic urticaria (15 patients), Urticaria-Vasculitis Syndrome (15 patients), Raynauds Disease (16 patients), and Raynauds phenomenon (15 patients). The investigations demonstrated that the test was always positive in cold urticaria and that a high percentage of patients had a rise in blood histamine. This was found in 50% of the patients while cryoglobulins were found in one third of the patients. Consequently they can be grouped in secondary cold urticarias. A number of patients with chronic urticaria and Urticaria-Vasculitis Syndrome gave a positive history of cold sensitivity. Positive tests were accompanied by a rise in histamine, although (less frequently) there was a decrease in the complement titer and the occurence of cryoglobulins. Raynauds Disease was accompanied by a positive test in 94% of the patients, while patients with Raynauds Phenomenon (whose etiology was Thoracic Outlet Syndrome) had a negative test (60% of the patients). Significant changes were not found in the remaining groups. Positive tests were accompanied by abnormal values of cryoglobulins and of complement titer as well as an increase in histamine. The rise in histamine was not significant in Raynauds Phenomenon, while one patient had a decrease in the complement titer and the appearance of cryoglobulins.