Quantity and quality of sweating in atopic dermatitis

Sweat may be an important factor in triggering an exacerbation of atopic dermatitis. It was the aim of this study to evaluate a possible correlation between atopic patients and hyperhidrosis—measured by a questionnaire—and to find out whether there are qualitative differences in sweat response—measured by sudomotor activity (sympathetic skin response test, SSR). Included were 100 study participants, of whom 50 were patients with atopic dermatitis and 50 were serving as control group. The frequency of hyperhidrosis is higher in atopic patients than in the control group (30 vs. 16%), but has no statistical significance. In addition, patients with hyperhidrosis and atopic dermatitis have a significantly higher exacerbation rate of atopic dermatitis in summertime. The group of atopic patients shows a statistically significant prolonged SSR latency period, which indicates an insufficient sympathetic innervation. In our tests, type IV allergic patients showed clear differences in terms of SSR latency and amplitude. Atopic patients have a higher incidence of hyperhidrosis. The study clearly shows that there is a dysfunction of sudomotor activity in the sympathetic nervous system of atopic patients. Our findings suggest that a deficient innervation of sweat glands in atopic patients may lead to an increase in the development of type IV allergies.