FUNGAL INFECTIONS

Tinea versicolor is a common, innocuous chronic fungal infection in adolescents, caused by a yeast, Malassezia furfur.

Predisposing factors, e.g. hot, humid environment, excessive sweating and steroid therapy leads to proli­feration of disease-producing filamentous form.

Clinically these lesions present as non-pruritic, confluent hypo/hyperpigmented patches over neck and upper trunk (Fig. 25.5G).

Diagnosis may be confirmed by wood's lamp examination (yellowish-gold fluorescence) and KOH preparation of scrapping.

Management includes topical application of selenium sulfide, salicylic acid or antifungal creams (e.g. mico­nazole, clotrimazole or ketoconazole) for 2-4 weeks, though lesions tend to recur in predisposed children and may require oral antifungal therapy.

Dermatophytoses (Ringworm) is a group of clinical fungal infections caused by three related filamentous fungi-Trichophyton, Microsporum and Epidermophyton. Infection is acquired from other humans, animals or directly from soil. Though common in even normal children, infection tends to be more severe in children with diabetes, high-steroid states, e.g. Cushing syndrome or steroid therapy, and immunosuppression.

Clinically these infections are named according to the site of lesion like Tenia captis (scalp), T. corporis (anywhere on body except palm, soles and groin), T. cruris (groin), T. pedis or athlete foot (toe webs) and T. ungium (nails).

Most tenia lesions begins as a tiny papule over the base of a hair follicle and spreads centrifugally with central clearing (ringworm) to form erythematous, scaly and pruritic plaques with brittle/broken hair over them (Fig. 25.5H).

Established cases of T. captis often present with multiple pruritic patches of alopecia over scalp. Similar lesions are seen in T. corporis and T. cruris, later being more common in adolescent males.

T. ungium presents as irregular white patches over nails, sometimes associated with paronychia. Later, the nail becomes brittle and discolored, which may crack or break-away from nail-bed.

Diagnosis is clinical, supported by microscopic examination of wet KOH preparation for spores and occasionally by culture of broken hair, skin scrapping or nail on Sabouraud media.

D/D includes alopecia areata, seborrheic dermatitis and trichotillomania (for T. capitis), nummular eczema, tinea versicolor and pityriasis rosea (for T. capitis), intertrigo, candidiasis and contact dermatitis (for T. cruris), atopic dermatitis, contact dermatitis, candidiasis and intertrigo (for T. pedis) and dystrophic nail disorders or nail trauma (for T. ungium).

Management: Topical antifungal therapy with mico­nazole, ketoconazole or clotrimazole twice daily for 2-4 weeks is usually enough for T. corporis, T. cruris and T. pedis. Cases with groin or pedal lesions should avoid use of tight innerwear/footwear.

For T. capitis or severe T. corporis, oral antifungal therapy with Griseofulvin (15 mg/kg/d) or itroconazole (3-5 mg/kg/d) for 6-8 weeks is necessary, along with vigorous shampooing (2.5% selenium sulfide) for scalp lesions. Oral Terbinafine (3-6 mg/kg/day) for 4-6 weeks may also be used in older children gt; 4 years.

T. ungium is most difficult to treat as topical therapy or oral griseofulvin is ineffective. Itroconazole (PO 6-10 mg/kg/d) for 7 days in a month for 4-6 months is the treatment of choice in these cases.

Cutaneous candidiasis is not uncommon in newborns and in older children during hot/humid climate, though extensive, refractory or systemic disease indicates underlying immunodeficiency.

Clinically, skin lesions are common over moist and macerated skin, presenting as cheesy-white plaques over intensely erythematous skin/mucosa, specially over flexural regions, e.g. diaper region (Fig. 25.5I), axilla, intertriginous region, vagina and nails (candidal paronychia).

Diagnosis may be confirmed by scrapping and KOH preparation.

Management: Topical antifungal therapy (clotrimazole, nystatin, miconazole) is enough for most cases, though a short course of topical steroids is indicated in acutely inflamed cases. Oral antifungal therapy with nystatin is needed in refractory or recurrent candidal lesions or nail infections.

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