Cutaneous fungal infections are common in children (Table 98-1). The estimated lifetime risk of developing a dermatophytosis is 10% to 20%. Diagnosis is usually established by visual inspection and may be confirmed by potassium hydroxide (KOH) examination or fungal culture of skin scrapings from the margins of the lesion. Recommended tinea treatment is usually for 4 to 6 weeks and 2 weeks after resolution; topical antifungal creams (e.g., miconazole, clotrimazole, ketoconazole, tolnaftate) are appropriate for tinea corporis, tinea pedis, and tinea cruris, whereas tinea capitis requires oral treatment. The diagnosis of onychomycosis should be confirmed by KOH examination and fungal culture. Recommended treatment is terbinafine or itraconazole for at least 12 weeks.
Available @ StudentConsult.com
Primary herpetic infections can occur after inoculation of the virus at any mucocutaneous site. Herpes simplex virus type 1 (HSV-1) is common in children and classically causes gingivostomatitis, whereas HSV-2 classically infects the genitalia as a sexually transmitted infection (see Chapter 116), though HSV-1 may cause approximately 30% of genital herpes, and
Microsporum audouinii, Prepubertal infection of scalp, M. audouinii fluorescence: Griseofulvin; terbinafine, (ringworm) Trichophyton tonsurans, hair-shafts; black dot alopecia; blue-green with Wood itraconazole Microsporum canis T. tonsurans common in African lamp*; +KOH, culture Americans
KOH, Potassium hydroxide. *Wood lamp examination uses an ultraviolet source in a completely darkened room. Trichophyton usually has no fluorescence.
HSV-2 can cause gingivostomatitis. For the cutaneous manifestations of neonatal HSV infection, see Chapter 65.
Herpes gingivostomatitis involves the gingivae and the vermilion border of the lips. Herpes labialis (cold sores or fever blisters) is limited to the vermilion border involving skin and mucous membranes. Clinical manifestations of primary HSV gingivostomatitis include typical oropharyngeal vesicular lesions with high fever, malaise, stinging mouth pain, drooling, fetid breath, and cervical lymphadenopathy.
Herpetic skin lesions are quite painful and characteristically begin as erythematous papules that quickly progress tothe characteristically grouped, 2-to 4-mm, fluid-filled vesicles on an erythematous base. Removal of the vesicle roofreveals a small, sharply demarcated ulcer with a punched-outappearance. The characteristic grouped vesicles distinguishHSV from chickenpox (see Chapter 97). Within several days,the vesicles become pustular, rupture, and encrust. Diagnosisis made clinically, or with viral culture, fluorescent antibody staining, or polymerase chain reaction. Scarring is uncommon, but there may be residual hyperpigmentation. After primary infection, the virus remains latent in nerve dorsal rootganglia. About 20% to 40% of adults experience recurrentoral episodes of HSV labialis throughout life. Recurrencesoccur in roughly the same location and may be preceded byprodromal symptoms of tingling or burning without fever orlymphadenopathy.