(Figure 4.24C) - Infection of the nail plate, most commonly due to T. rubrum, but also by other dermatophytes, yeast, and nondermatophytic molds
- Four types:
- Distal subungual onychomycosis: involvement of distal nail bed and hyponychium; typically due to T. rubrum
- White superficial onychomycosis (WSO): chalky white superficial infection of nail plate; mainly due to T. mentagrophytes (of note, T. rubrum more common in HIV patients)
- Proximal subungual onychomycosis: least common form, presents with areas of leukonychia in proximal nail plate near lunula; usually due to T. rubrum; can be a sign of HIV infection
- Candida onychomycosis: destruction of nail and massive nail bed hyperkeratosis, typically seen in patients with mucocutaneous candidiasis; due to C. albicans
- Treatment: oral terbinafine 250 mg qd × 6–8 weeks for fingernails and 12–16 weeks for toenails
| | | | | | | | Microsporum | | | Microconidia – not distinctive
Macroconidia – diagnostic (rough-walled, multicelled, and barrel-shaped)
May cause both fluorescent and nonfluorescent ectothrix infections |
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| | Figure 4.24
A: Tinea capitis
(Courtesy of Dr. Paul Getz)
B: Tinea pedis, interdigital
C: Onychomycosis |
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