The capillary dilatation which occurs in psoriasis and the hypothesis that psoriasis may be an expression of altered capillary permeability made it of interest to investigate the effect of vitamin P on this disease. Since the source material of vitamin P (citrin) is lemon and since one of the preparations used was a modified lemonade, it was thought advisable to include in the study a control group of patients treated by ascorbic acid.
Zorn1 has stated that the scales from psoriatic lesions consist of those not only from the cells of the epidermis but also partly from solidified plasma. He further stated that the specific cutaneous changes all begin with capillary hyperemia and extravasation of plasma. In his paper he discussed two problems: 1. Which components of plasma cause dilatation of capillaries and changes in the permeability of the walls? 2. What is the reaction to this stimulation of
GOLDFARB AE. TREATMENT OF PSORIASIS WITH LEMON CITRIN (VITAMIN P), CITRIN LEMONADE AND ASCORBIC ACID. Arch Derm Syphilol. 1941;43(3):536–538. doi:10.1001/archderm.1941.01490210104010