Although antihistamines are generally not effective for pruritus associated with allergic contact dermatitis, they are commonly used. Sedation from more soporific antihistamines (., diphenhydramine [Benadryl], hydroxyzine [Vistaril]) may offer some degree of relief. 4 Emollients, moisturizers, or barrier creams may be instituted as secondary prevention strategies to help avoid continued exposure. 4 To prevent irritant contact dermatitis of the hands, persons should avoid latex gloves; wear nonlatex gloves when working with potentially irritating substances, such as solvents, soaps, and detergents; use cotton liners under the gloves for comfort and absorption of sweat; and keep hands clean, dry, and well moisturized when possible.
Steroid allergy resulting in immediate hypersensitivity seem to be very rare relative to their worldwide use. The literature that was reviewed over 11 years identified 120 reactions, and 60% resulted in anaphylaxis. Some patients had more than 1 reaction on separate occasions and some responded to more than 1 preparation of steroids. The problem is most likely under diagnosed or under reported, particularly because steroids are a common therapy for allergy and hypersensitivity disorders. One should always be aware of this entity, even though it is rare. There are other safe alternative preparations through screening and allergy skin testing or a graded challenge. In rare cases when an alternative can no be used, desensitization by an experienced allergy specialist can be pursued.
Paraphenylenedeamine (PPDA) is an ingredient found in permanent hair dyes. This ingredient is mixed with an oxidizing agent, such as peroxide, before application. People allergic to PPDA should not use any permanent hair dyes. About one fourth of the people allergic to PPDA are also allergic to ingredients in semi-permanent dyes. Follow the package instructions for a patch test before using any hair dye. Most PPDA allergic people can use temporary dyes or rinses, to blend in gray and brighten hair. A few people, however, will react to these dyes also.