Skin Ailments—Tinea
Fungal disease affecting the skin
General—superficial infection of keratin-containing tissues including skin, nails, and hair shafts
Etiology
Dermatophytes (Trichophyton, Microsporum, Epidermophyton) = tinea
Yeast (Candida) (see Chapter 2.12)
Dermatophytes (tinea)
General—consist of spores and hyphae that afflict soft keratin of the skin in different body locals.
Epidemiology—10% to 20% lifetime risk of acquiring a tinea infection.
Diagnostic evaluation
A 20% potassium hydroxide (KOH) preparation is used to visualize hyphae.
Obtain sample by scraping lesion with a no. 15 blade scalpel or the edge of a slide.
Culture is rarely indicated, although it may help direct oral therapy.
Biopsy with periodic acid-Schiff stain when the diagnosis remains in question.
Classification and treatment
Tinea pedis (athlete’s foot)
General—most common fungal infection of the skin
Clinical—erythematous scaling plaques, pruritic, presents as
Maceration between the toes (toe-web distribution)
Diffuse erythema affecting the soles (moccasin distribution)
Etiology—most commonly caused by the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes
Risk factors—occlusive footwear
Treatment
Topical—apply medication to include skin approximately 2 cm beyond the affected area.
Combination topical treatment
Betamethasone/clotrimazole (Lotrisone) 0.05%/1% cream—apply BID up to 4 weeks.
Systemic treatment
Adverse effect—reversible hepatitis, so watch liver function tests (LFTs).Related posts:
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