[Laboratory studies of long-term photochemotherapy of psoriasis vulgaris].

The study of 40 laboratory parameters from a total of 40,000 individual samples taken from patients who had been treated by means of systemic PUVA therapy for a period up to three years did not reveal any evidence for negative influences on selected peripheral blood enzymes, substrates, metabolites, proteins, lipid fractions, electrolytes, antistreptolysin titer, rheumatoid factors and coagulation values, or urinalysis values. The changes observed were either statistically insignificant, remained within normal ranges, or could not be classified. Under the conditions described, no evidence for chronic toxic organic manifestations could be found, even after several years of PUVA treatment.