fungal nail infection

Question 1

define + list causes

Answer 1

Fungal nail infections

Onychomycosis is fungal infection of the nails. This may be caused by

• dermatophytes - mainly Trichophyton rubrum, accounts for 90% of cases
• yeasts - such as Candida
• non-dermatophyte moulds

Question 2

RFs

Answer 2

Risk factors include for fungal nail infections include diabetes mellitus andincreasing age.

Question 3

s/s

Answer 3

Features

• ‘unsightly’ nails are a common reason for presentation
• thickened, rough, opaque nails are the most common finding

Question 4

Differential diagnosis

Answer 4

• psoriasis
• repeated trauma
• lichen planus
• yellow nail syndrome

Question 5

Investigation

Answer 5

1. nail clippings
2. scrapings of the affected nail
3. the false negative rate for cultures are around 30%, so repeat samples may need to be sent if the clinical suspicion is high

Question 6

mx

Answer 6

Management

• treatment is successful in around 50-80% of people
• diagnosis should be confirmed by microbiology before starting treatment
• dermatophyte infection: oral terbinafine is currently recommended first-line with oral itraconazole as an alternative. Six weeks - 3 months therapy is needed for fingernail infections whilst toenails should be treated for 3 - 6 months
• Candida infection: mild disease should be treated with _topical antifungals (_e.g. Amorolfine) whilst more severe infections should be treated with oral itraconazole for a period of 12 weeks