52 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS rate quickly and cause no trouble. The chief offending ingredient has been the sulfonamide-formaldehyde resin. The dyes, especially the fluorescent ones have also been offenders. The lesions are usually of the type of lichenified eczema, but acute dermatitis with severe edema especially of the eyelids is occasionally encountered. When chronic eczematoid lesions occur on the face and neck of women who use nail lacquer, the diagnosis of nail- lacquer dermatitis must be con- sidered. The diagnosis is estab- lished by uncovered patch tests with the nail lacquer and each of its ingredients. PERFUME Perfumes are presented in most cosmetics. The fact that in the last 20 years we could only find 18 references to dermatitis from per- fumes attests to the rarity of its occurrence. As perfumes are complex mix- tures, it is often impossible to fix the blame on any one chemical com- pound. Linalool, methyl heptine c•,.,arbonate, oil of bergamot, oil of lavender, oil of o. rris, oil of mint, and benzylidene acetone have been re- ported as actual causes. The oil of bergamot and oil of mint cause photosensitization dermatitis. Methyl heptine carbonate and benz- ylidene acetate are synthetics. The diagnosis of allergic derma- titis from perfumes is established by uncovered patch tests. It may re- quire tracing .the perfume to its blender to find the actual ingredi- ents. If this can be done, patch tests may be performed with the in- gredients to find the actual irritant. POWDERS These rarely cause dermatitis. Only 4 cases of dermatitis have been reported from powders in the last 12 years. Two of these were due to the dyes and 2 were caused by the powder conveyors, in 1 instance a rubber powder conveyor and in the other instance a dirty one conveyed a bacterial infection. Orris root, the allergists bug-a- boo, has not been used by reputable cosmetic manufacturers as an in- gredient in powder ever since the notorious case in Massachusetts. When face powder is suspected as the cause of a dermatitis, patch tests should be performed with the powder, and if positive, with each ingredient in the powder. The drying effect of a p6wder containing an absorptive base such as kaolin, Kieselguhr, etc., must be consid- ered, as a cause of dermatitis if there are no reactions to the patch test. PRESERVATIVES While no cases of dermatitis have been reported from cosmetic pre- servatives, the possibility must not be overlooked. When patch tests are positive with a cosmetic and are negative with the ingredients of the cosmetic, the physician should ascer- taif• if it contains a preservative or anti-oxidant and if it does, he should perfc rm patch tests with it, using the same base and dilution as is contained in the cosmetic.

DIAGNOSIS OF COSMETIC DERMATITIS 5 SuN-TAN PREPARATIONS Dermatitis has not been reported from sun-tan preparations. This does not mean that it does not occur. It may be attributed to the sun. When a well-known sun-tan prepa- ration properly used does not pro- tect a patient against the burning solar rays, or when a patient using a sun-tan preparation develops a severe case of sunburn which per- sists for a week or longer, the physi- cian should suspect the preparation. Patch tests should be performed on covered parts of the body, the back or thighs, and the reaction read be- fore the part is exposed to sunlight. The diagnosis of dermatitis from cosmetics in the majority of cases, is not difficult to the dermatologist who is familiar with the ingredients used in cosmetics, and in most in- stances, the actual irritant can be found. But in some cases, not only a thorough knowledge of cosmetics and dermatology, but also the in- genuity and persistence of a Hohnes are required, to discover the actual cause of a suspected case.of cosmetic dermatitis.