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Surgical excision if malignancy suspected.
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ONYCHOMYCOSIS (TINEA UNGUIUM)
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Etiology: Dermatophyte infection of nail plate, often associated with tinea pedis. Less commonly due to yeasts and nondermatophyte molds.
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History: Change in nail color and more brittle; usually asymptomatic.
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Physical: Yellow discoloration, thickening, nail dystrophy, subungual hyperkeratosis, onycholysis. Toenails > fingernails.
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Patterns include the distal subungual form (most common), the proximal white subungual form (may be a sign of HIV disease), and the white superficial form.
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Investigations: 20% KOH direct microscopy, nail clipping/scraping for culture.
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DDx: Nail psoriasis or trauma, eczema, lichen planus.
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Topical antifungals much less effective. Ciclopirox (Penlac®) nail lacquer may be tried if po Tx not an option.
Important to culture fungus prior to initiating oral Tx
Terbinafine (Lamisil) 250 mg po qd × 6 wk for fingernails, × 12 wk for toenails; itraconazole (Sporanox) 200 mg po bid × 7 d, then 3 wk off—2 pulses for fingernails, 3 pulses for toenails.
Other less common options: Griseofulvin (esp. in kids), fluconazole.
Hepatotoxicity and ...