Acute irritant reactivity to sodium lauryl sulfate in atopics and non-atopics

Predictive testing of chemicals to assess their acute skin irritation potential is an important part of the assessment of their toxicological profile. It is possible, where safety and ethical considerations can be met, to do this work in groups of human volunteers. Previously, the relative responsiveness of atopics and non-atopics has been evaluated. The results showed that atopics (defined broadly by high IgE reactivity) were a little more susceptible to skin irritation, but not significantly so. In the present work, the relative reactivity of a skin atopic group versus a non-atopic group was examined in more detail. Sodium lauryl sulfate (SLS) was applied at a range of concentrations and exposure times, such that a fairly constant degree of skin irritation was produced. At various time points, the irritation response was measured by visual assessment, chromametry, laser Doppler flowmetry and transepidermal water loss. Using all of the methods of assessment, the reactions in atopics were similar to or a little less than those seen in non-atopics. The conclusion is that atopics and non-atopics will give similar results in a predictive human test for acute skin irritation. Furthermore, the pattern of response obtained from short duration exposure should be predictive of that following longer durations of (single) exposure.