[Proteinuria in dermal vasculitis (incidence, degree and possible mechanisms of onset)]

The paper comprises 63 patients with diagnosed vasculitis of the skin who had abnormal findings in the urine. Thirteen of these patients had positive skin findings and abnormal findings in the urine, with concomitant attacks of dyspnea as seen in bronchial asthma. These patients account for 20% of the entire group, while there was an incidence of 37% of systemic manifestations. Skin findings: 45% had a maculopapular rash, 36% had urticarial findings, 13% had urticaria and angioedema and 6% had angioedema alone. Nonspecific biologic syndrome of evolution was statistically significant while no significant changes were found in the number of white blood cells and eosinophils. The degree of proteinuria ranged from 0.1 g/L to 1.16 g/L. Most patients with proteinuria above 0.25 g/L had microhematuria. Slightly over 50% of the patients had signs of complement activation by the alternative pathway, along with the presence of cryoglobulins. Increased histamine in the serum was found in over 50% of the patients although the values of histamine did not correlate with the degree of proteinuria. Proteinuria was not detected in patients with very high values of histamine (and without signs of vasculitis), which indicates that histamine itself responsible for changes in the glomeruli. There is a possibility that local tissue hyperhistaminemia is responsible for the increased permeability of the basal membrane of the glomeruli. According to the obtained results, the etiology of proteinuria and microhematuria should be pursued in the pathogenesis of vasculitis as signs of complement activation indicate. Other possible causes for proteinuria were excluded. The proteinuria was selective, benign according to its course and degree, occurred concomitantly with skin findings and was absent during remission of the disease.