Clinical and histological characterization of transient dermal pain triggered by sweating stimuli.

BACKGROUND

Tingling dermal pain triggered by sweating impairs the lives of patients with cholinergic urticaria and generalized anhidrosis. However, dermal pain evoked by sweating stimuli has been under investigated.

METHODS

To clarify characteristics of tingling dermal pain on sweating, we retrospectively evaluated clinical and histopathological manifestations in 30 patients having the main problem of dermal pain on sweating, and the efficacy of treatments.

RESULTS

Dermal pain upon sweating affected mostly young males. It accompanied eruptions upon sweating and/or hypohidrosis in 24 patients, while 6 patients had dermal pain independently of hypohidrosis or eruptions. Dermal pain appeared immediately upon exposure to sweating stimuli, and disappeared within mostly 30 or 10 min. Hypohidrosis was not necessarily generalized but localized or absent. Histological analysis revealed that dermal pain could occur even without morphological changes and inflammation of sweat glands. Hypersensitivity to sweat contents was found only in 26% of patients. Sweat histamine and increase of plasma histamine after thermal induction in patients were significantly higher than those in healthy subjects. Effectiveness of steroid pulse therapy was demonstrated for dermal pain with hypohidrosis. Medications acting on nervous systems and regular sweat-inducing activities for promoting perspiration were also effective.

CONCLUSIONS

Short-lasting tingling dermal pain appears immediately upon exposure to sweating stimuli, regardless of developing eruptions and/or presence of hypohidrosis, but possibly in association with sweat and plasma histamine.