Reduction of Skin pH during Treatment for Palmoplantar Hyperhidrosis: A Conjecture on the Role of pH-Regulated Water Channel, i.e. Aquaporin
A 45-year-old woman (case 1) and a 27-year-old woman (case 2) suffered from PPH since childhood. Case 1 was initially treated by topical AC application. Three weeks later, she underwent weekly TWI with a direct current at 12 mA for 20 min. The sweating was slightly reduced in 4 weeks and was markedly reduced in 8 weeks. Case 2 was treated with a daily application of 20% AC solution. The sweating was slightly reduced in 2 weeks and was markedly reduced in 4 weeks.\nSkin surface pH was measured using a skin pH meter (D-51, Horiba, Ltd., Tokyo, Japan) according to the manufacturer's protocol. The design was validated in a pilot study. The experiment was performed in a room with a temperature of 24°C and humidity below 65%. The patients were kept at rest and the measurement was conducted after the skin was slightly wiped with tissues. The mean pH values were calculated in four sites on both the palms and soles. Twelve healthy volunteers (7 males and 5 females, mean ± SD age 33.6 ± 5.5 years, range 24–46) were also enrolled in the study.\nThe pH of patients with PPH before treatment tended to be high compared to that of healthy subjects (pH of healthy subjects, 5.23 ± 0.22; pH of PPH, 6.17 in case 1 and 6.65 in case 2). The comparison of pH before and after the antihidrotic therapy was analyzed by the paired t test (fig. ). In both cases, the skin pH was significantly decreased following the treatment and was accompanied by reduced sweating.