Topical drugs can be absorbed percutaneously in sufficient amounts to cause untoward systemic effects. Generally speaking, infants and young children appears to be more vulnerable than adults. It has been shown that the prolonged and extensive use of topical corticosteroids can induce iatrogenic hypercorticism and that they may also impair the patients ability to cope with stress. Furthermore, the relatively limited use, areawise and timewise, of agents such as phenol, resorcinol, salicylic acid, hexachlorophene, boric acid, mercurials, and podophyllin may suffice to elicit dire systemic reactions.