Mechanisms of subjective (sensory) irritation. Propensity to non-immunologic contact urticaria and objective irritation in stingers.

Subjective (sensory) irritation was studied with lactic acid test on 74 females; 8 reacted positively with "stinging" and/or itching or burning and another 5 had mild subjective sensations. History of previous corresponding sensations from contact with cosmetic products was significantly more common in stingers than in non-stingers (p less than 0.001); other factors, such as dermatologic history, sensitivity to ultraviolet light or skin dryness had no characteristic patterns. In the objective, immediate non-immunologic contact urticaria tests with sorbic acid and benzoic acid, the stingers developed significantly more erythema to 0.5% sorbic acid (p less than 0.05) and to 1% benzoic acid (p less than 0.02). 1% sorbic acid also induced more edema in stingers (p less than 0.02). Increased reactivity to a 24 h sodium lauryl sulfate (SLS) patch test was demonstrated only with laser Doppler velocimetry (p less than 0.05). Stingers and non-stingers reacted similarly to open, cumulative SLS irritation as measured with transepidermal water loss. These studies provide clinical and biological information about subjective irritation; the data suggest a functional correlation for the what had been considered a purely subjective (sensory) phenomena.