Serum antidiuretic hormone is elevated in relation to the increase in average total body transepidermal water loss in severe atopic dermatitis.

BACKGROUND

While elevation of antidiuretic hormone (ADH) (arginine vasopressin) levels in the serum has been reported in severe atopic dermatitis (AD), the cause is as yet unexplained. On the other hand, transepidermal water loss (TEWL) is known to increase in the damaged skin due to AD.

OBJECTIVES

As ADH increases as a result of dehydration of the body, this study examined whether the high ADH level in severe AD is a reaction to the increased water loss through the entire body skin surface area.

METHODS

Forty-eight patients of different ages and with various degrees of AD along with six age- and sex-matched control persons were the study subjects. Using a quick responsive evaporimeter, an average total body TEWL (ATEWL) value was obtained for each subject. Laboratory tests including ADH, serum lactate dehydrogenase (LDH) and peripheral blood eosinophil count (EOS) were also performed. Clinical severity grading was made globally. The relevancy of this grading was empirically demonstrated by its statistically significant relation to LDH and EOS which are commonly known as appropriate gauges for AD severity. Results ATEWL was observed to be significantly greater in patients with AD of at least moderate severity than in normal controls, and ADH was significantly greater in patients with severe and very severe AD. Both ATEWL and ADH showed a significant relation to AD severity. Finally, a significant correlation was found between ADH and ATEWL.

CONCLUSIONS

It is possible that elevated ADH is at least in part a reaction to increased ATEWL.