FORTNIGHTLY REVIEW - FUNGAL NAIL DISEASE - A GUIDE TO GOOD PRACTICE (REPORT OF A WORKING GROUP OF THE BRITISH-SOCIETY-FOR-MEDICAL-MYCOLOGY)

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 offending organism. In paronychia chronic infection of the nail fold is most often coused 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 state (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.