Pediatric emergency medicine trisk 1846 1846

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 5 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.