Predisposing factors on the surface of the skin in persons with pityriasis versicolor.

This is a report on biochemical and physiological examinations carried out on 20 test persons who in the last 2 years had contacted and completely recovered from pityriasis versicolor and on 25 control persons of corresponding age and sex. The tests on the skin surface of the patients with pityriasis versicolor show, when compared with the corresponding control group, the following significant results: 1. Significantly more amino acids could be extracted from the skin of the pityriasis versicolor patients than from the skin of the control persons. 2. A significantly shorter alkali neutralisation time was to be found in the pityriasis versicolor patients than in the control persons. 3. The degree of water spreading on the skin was found to be significantly reduced in the pityriasis versicolor patients when compared with the control persons. It is probable that these results point to important predisposing factors for pityriasis versicolor.