Pruritus that is refractory to moisturizers and conservative measures can be treated with antihistamines or tricyclic antidepressants. Compared with the newer, nonsedating histamines, the older, sedating agents such as hydroxyzine (Atarax) and diphenhydramine (Benadryl) are more effective in controlling pruritus. 20 However, these agents can affect a child's ability to learn or an adult's ability to drive and work. 21 If drowsiness is a problem, a nonsedating antihistamine can be tried to see if it is effective. Tricyclic antidepressants such as doxepin (Sinequan) and amitriptyline (Elavil) also have an antihistaminic effect, induce sleep and reduce pruritus. 22
The most common side effect of topical corticosteroid use is skin atrophy. All topical steroids can induce atrophy, but higher potency steroids, occlusion, thinner skin, and older patient age increase the risk. The face, the backs of the hands, and intertriginous areas are particularly susceptible. Resolution often occurs after discontinuing use of these agents, but it may take months. Concurrent use of topical tretinoin (Retin-A) % may reduce the incidence of atrophy from chronic steroid applications. 30 Other side effects from topical steroids include permanent dermal atrophy, telangiectasia, and striae.
Transdermal patches can be a very precise time released method of delivering a drug. Cutting a patch in half might affect the dose delivered. The release of the active component from a transdermal delivery system (patch) may be controlled by diffusion through the adhesive which covers the whole patch, by diffusion through a membrane which may only have adhesive on the patch rim or drug release may be controlled by release from a polymer matrix. Cutting a patch might cause rapid dehydration of the base of the medicine and affect the rate of diffusion.