Evidence for the efficacy and safety of topical herbal drugs in dermatology: Part I: Anti-inflammatory agents.

Topical herbal drugs have for centuries been used for treating skin ailments. Although they are currently widely accepted by patients, their scientific esteem among dermatologists in particular is limited. A variety of herbal drugs for topical application deserves consideration regarding their widespread use or their still ill-defined potential with respect to their benefit/risk ratio. Clinically, camomile (Chamomilla recutita) and hamamelis preparations look particularly well documented. While the final proof of efficacy in common dermatoses such as atopic dermatitis is still lacking, there is fairly ample evidence for their activity against cutaneous inflammation in man, as may be deduced from experiments with normal volunteers. With Hamamelis virginiana this looks paricularly promising, as unwanted effects related to the drug are virtually absent. With camomile preparations the degree of safety seems to depend largely on the plant used. Some herbal drugs clearly need further analysis until their value can be determined. This includes the frequently-used aloe preparations. This is the more remarkable as huge numbers of in vitro studies are available. Arnica is fairly unique in so far as the lack of proof of efficacy strongly contrasts to its sensitization potential. So far, in particular dermatitis and related disorders can be considered potential indications for topical herbal antiinflammatory drugs. Studies in psoriasis vulgaris should also be performed addressing long-term application. In this context such fairly ill-defined drugs as Mahonia deserve attention.