Medical Service

Sweat sensitivity and skin allergy

Many patients suffering from atopic dermatitis complain of itching and worsening of their rash after sweating. Many patients with atopic dermatitis have been found to have an allergic sensitivity to an as yet unidentified antigen in their own sweat. The majority of these patients develop positive skin test reactions to a 1,000 to 10,000-fold diluted preparation of their own sweat, whereas only 1% of the normal population has a similar reaction.

Another condition known as cholinergic urticaria has now been confirmed to be due to sweat allergy. These patients develop extremely itchy small hives on their skin when they are hot or when they exercise. The majority of these patients also have positive sweat skin test.

More interestingly, recent clinical studies in Japan suggest that sweat desensitization treatment might be effective for these conditions. Six Japanese patients with cholinergic urticaria underwent desensitization by intradermal injections of escalating doses of their own sweat. Five out of six patients showed significant symptomatic improvement. We have started to offer sweat skin test to our patients who have symptoms of sweat allergy. In those patients with positive reactions, sweat desensitization might be a viable treatment option. This might be particularly valuable to those patients suffering from cholinergic urticaria, as there is currently no other viable treatment option for these patients except antihistamines.