and peeling of the skin suggestive of tinea pedis in prepubertal children more often indicates the presence of atopic eczema or hyperhidrosis KOH preparation will demonstrate hyphae, especially when samples are taken from between the fourth and fifth interspaces of the toes Clinically, the skin has a dry, white, hazy appearance and is often pruritic When secondary bacterial infection is present, an odor occurs At times, an inflammatory lesion (caused by T mentagrophytes ) causes blistering The presence of an id reaction indicates dissemination of antigen to other parts of the body, especially the hands The differential diagnosis of tinea pedis includes simple maceration, contact dermatitis, and atopic eczema Treatment consists of drying the feet thoroughly after washing; wearing dry, clean socks; avoiding caffeine-containing foods to decrease sweating; keeping shoes off as much as possible; and walking barefoot or in sandals Topical antifungal agents and/or oral griseofulvin are used to treat this condition Tinea Versicolor Tinea versicolor refers to a superficial infection of the skin caused by Malassezia , which produces color changes of the skin, hypopigmentation, hyperpigmentation, and sometimes a salmon-colored redness ( Figs 88.17 and 88.25 ) Wood light examination usually shows yellowish-brown fluorescence Because moisture promotes growth of the organism, exacerbations occur in warm weather or in athletes who sweat excessively The infection is difficult to eradicate and recurs frequently A KOH preparation shows short, stubby hyphae and large clusters of spores, often referred to as “spaghetti and meatballs.” Treatment consists of lathering the entire body with selenium sulfide shampoo (2.5% concentration) or ketoconazole shampoo after wetting the skin surface in a shower The lather is left on for to 10 minutes and is then showered off This procedure is carried out daily during the first week, with decreasing frequency over the ensuing weeks Maintenance therapy once weekly throughout the summer or warmer seasons is advisable because of the high incidence of recurrence Localized areas of involvement can be treated with topical antifungal agents (e.g., econazole, ketoconazole topically) Adolescents can be treated with 150 mg of fluconazole given once or at monthly intervals during the warm summer months or during a sports season when the patient sweats frequently Because tinea versicolor tends to be a recurrent problem, retreatment in subsequent years may be necessary