Intended for healthcare professionals
Onychomycosis is usually caused by dermatophytes (85-90%),butseveral fungi that are difficult to treat affect toenails
Paronychia is caused by many Candida species, some resistant to azole drugs
Samples for mycology should be taken as proximally as possible in the nail
Demonstration of hyphae in a nail specimen by microscopy is sufficient to start treatment
Choice of treatment depends on many factors including patient's age and preference,infecting fungus, number of nails affected, degree of nail involvement,whether toenails or fingernails are infected, and other drugs being taken
The term onychomycosis refers to fungal infection of the nails whether this is a primary event or a secondary infection of a previously diseased or traumatised nail. Infection may be due to dermatophyte (ringworm, tinea unguium), yeast, or other non-dermatophyte (mould) species, and the clinical appearance may indicate the nature of the infecting organism. In paronychia chronic infection of the nail fold is most often caused by Candida species, but bacterial infection with Gram negative species such as Pseudomonas may coexist. Acute paronychia (whitlow) due to staphylococcal infection may also occur, and the presence of these bacterial infections will influence management. Invasion of the nail plate by Candida species may occur in the presence of paronychia, immune deficiency states (including chronic mucocutaneous candidiasis), Raynaud's disease, or endocrine disorders.
This paper reviews the clinical features of onychomycosis and the differential diagnosis of nail dystrophy, gives the reasons for appropriate mycological investigation, and discusses guidelines for appropriate treatment on the basis of laboratory findings and particular clinical situations.
Treating onychomycoses is difficult but is important because they do not resolve spontaneously. About 30% of all superficial fungal infections affect the nail.12 A recent population survey of dermatophyte onychomycosis has suggested a prevalence of 2.8% for men and 2.6% for women in the United Kingdom.3 …
Subscribe and get access to all BMJ articles, and much more.
* For online subscription
Access this article for 1 day for:
£50 / $60/ €56 (excludes VAT)
You can download a PDF version for your personal record.