Onychomycosis

Onychomycosis/Tinea unguium

Fungal infection of nail. Most likely due to:
Trichophyton rubrum
Trichophyton metagrophytes
Epidermophyton flocossum

Clinical features:
Distal subungual onychomycosis (Type 1):
Also called distal lateral onychomycosis
Most common type
Starts at free edge or lateral borders of nail as streaks of grey, white or yellow discolouration  spreads proximally
Layers of nail plate may separate
Hyperkeratotic mass of underlying nail bed may push nail plate loose from nail bed

Superficial white onychomycosis (Type 3):
• Rare in finger nails – more common in toenails
• Starts as small white patches on surface of nail  may progress to entire nail plate
• Tends not to penetrate deeply
• T. metagrophytes is most common

Proximal subungual onychomycosis (Type 2):
• Rarest type – gains entry via stratum corneum at proximal nail fold
• Appears distally as a white spot near lunula and begins to grow distally
• T. rubrum is most common

Candida subungual onychomycosis (Type 4):
• Candida albicans is opportunistic – usually infects following paronychia
• Nail appears opaque, brownish and altered in shape

Total dystrophic onychomycosis:
• Entire nail plate is affected – difficult to determine where original infection started

Treatment:
• Aggressive debridement
• often difficult with topical preparations – nail bed may be infected and the nail acts as a barrier to absorption of topical preparations
• topical application should be accompanied with regular debridement of nail
Topical agents:

Systemic agents:

Surgical:
• removal of nail plate with or without chemical cautery (phenolisation) of nail matrix – if do not destroy matrix  use antifungal during regrowth

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