Tinea unguium is a fungal infection of the nails.
Nails, composed of keratin, make an excellent fungal culture medium, particularly if moisture is added. Fungi most commonly invade from the distal end.
Tinea infections of the nails are uncommon in younger people who have a fairly rapid growth rate of their nails. As nail growth rates are slow, the fungus is more likely to be able to invade progressively up the nail.
Clinically, there is a white crumbling nail. The nail may be thickened. Tinea at the proximal edge of the nail is uncommon, except in patients who are immune-compromised.
Potassium hydroxide examination of clippings from the nail will show typical fungal hyphae.
The broad term onychomycosis includes tinea unguium, Candida and Hendersonula, and Scopulariopsis brevicaulis.
- Treatment of choice of tinea unguium is probably oral terbinafine daily for four months.
- Itraconazole and griseofulvin are also effective but treatment times are longer, and in the case of the much cheaper griseofulvin, treatment failure is very common.
- Scopulariopsis treatment may well require avulsion of the nail followed by topical and/or systemic azoles until a normal nail grows.