Sensitization Potential of Citronellol

The fragrance material citronellol has been cited as a moderately frequent cause of allergic contact dermatitis. A review of the literature shows that when the underlying clinical and experimental data are analyzed, a clear cause-effect relationship has infrequently or rarely been established. On the basis of its generally weak sensitizing potential in animals and human volunteers, coupled with its generally low exposure conditions, the prevalence of clinical cases would not be expected to be particularly high. This is not to say that citronellol is a frequent inducer of type IV allergy in members of the public. It remains to be seen, however, how often such allergy, once established, is responsible for any of the cases of allergic contact dermatitis commonly described in the literature. Indeed, in some cases, patch test conditions may not be optimal for differentiating between clinically relevant and irrelevant allergy to citronellol. Clarification of patch-test-related clinical relevance may be obtained utilizing retesting, dilution series and use tests.