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FIGURE 88.24 Nonscarring alopecia on the scalp of a child characteristic of alopecia areata.

Tinea Cruris
Tinea cruris begins as a small, red, scaling rash in the groin that spreads
peripherally and clears centrally. The edges are sharply marginated and scalloped,
extending down the thighs. Generally, the scrotum is not noticeably involved.
Other conditions to consider are seborrheic dermatitis (which usually can be
differentiated by involvement of other areas of the body such as the ears, scalp,
and eyelids), intertrigo (generally secondary to friction and maceration), contact
dermatitis, candidiasis (which usually involves the inner thigh and causes the
scrotum to appear bright red), and erythrasma (which will fluoresce under Wood
lamp). The clinician should always check the feet to ensure there is no fungal
involvement in that area as well. In general, this condition affects only
postpubertal children. Diagnosis is made by KOH preparation. Nonspecific
measures for treatment include loose-fitting clothing, reducing the amount of
perspiration. Clotrimazole, miconazole, tolnaftate, and econazole are useful as
topical antifungal agents. Rarely, oral griseofulvin may be needed in severe cases.
Tinea Pedis
Tinea pedis is generally caused by Trichophyton rubrum or Trichophyton
mentagrophytes. It occurs most commonly in postpubertal children. The cracking


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.


FIGURE 88.25 Scaly hyperpigmented patches consistent with tinea versicolor.

PAPULOSQUAMOUS ERUPTIONS/SCALY RED PATCHES
AND PLAQUES
Papulosquamous eruptions are discussed in Chapter 70 Rash: Papulosquamous
Eruptions and Viral Exanthems . These are conditions that are a mixture of
papules or plaques with scale. They are often red but can be more pink or purple
in color as in lichen planus.

Conditions That Lack Pruritus
Pityriasis Rosea
For more information about pityriasis rosea, see Chapter 70 Rash:
Papulosquamous Eruptions and Viral Exanthems . This is a harmless skin
condition that generally occurs in preadolescents to adults and contains scaly pink
or red plaques often in a “Christmas tree” distribution on the back ( Fig. 88.18 ).
There are atypical variants that are more papular and scaly and include the head
and neck. One should consider secondary syphilis in the differential of pityriasis
rosea ( Fig. 88.20 ). Guttate psoriasis should also be included in the differential.
Secondary Syphilis
Please see previous discussion in this chapter.

Pruritic Papulosquamous Disorders


Lichen Planus
Lichen planus is seen occasionally in pediatric patients as a chronic, pruritic,
reddish-blue (violaceous) to purplish eruption. Two percent to 3% of cases occur
in patients younger than 20 years of age.

FIGURE 88.26 Purple polygonal papules consistent with lichen planus.

The eruption generally involves the flexors of the wrist, forearms, and legs,

especially the dorsum of the foot and ankles. The highly pruritic lesions appear as
small, violaceous, shiny, flat-topped, polygonal papules ( Fig. 88.26 ). These
qualities may be recalled with the alliterative mnemonic of the five p’ s: p ruritic,
p urplish, p lanar, p olygonal, p apules. Some add a sixth p indicating a
predilection for so-called “private” areas such as penis or vulva. The surface of
these papules may have white cross-hatching, called Wickham striae. Lesions
may occur in sites of trauma or injury (Koebner phenomenon). The scalp may be
involved, often resulting in a scarring alopecia, called lichen planopilaris. It is
important to examine the buccal mucous membranes and the genital areas for a
reticulated or lace-like pattern of white papules or streaks. This finding is
characteristic for lichen planus. The nails are often pitted, dystrophic, or ridged
(pterygium nails). The lesions in lichen planus can be vesicular or bullous.
Hypertrophic and linear lesions occur but are less common. Persistent, severe,
postinflammatory hyperpigmentation is common in African Americans. In twothirds of patients, the lesions clear within 8 to 15 months. The cause of the
disorder is unknown. Topical therapy with steroids can be helpful, and treatment
with oral steroids may be necessary for extremely symptomatic patients. For