A 40 year old lady with rare fungal bone infection as cause of chronic toenail deformity
Mrs C is a lovely, fit, well and very active 40 year old lady referred to Dr Touzell by her podiatrist and General Practitioner due to a six month history of left great toenail pain, infection and nail deformity. Her podiatrist had very appropriately trialled avulsing the nail and debriding the nail bed and also involved Mrs C's General Practitioner for antibiotic therapy. Unfortunately the infection recurred despite two courses of antibioitc treatment and several nail debridements.
The only history of trauma that Mrs C could recollect was a sore toe after waterskiing six months prior to her presentation.
Clinically, Mrs C had a very deformed, swollen, irritated great toe (see below). She did not have a fever but said she felt 'off'. There was no history of chills or rigours, or painful joints elsewhere that could suggest multi-focal infection.
An x-ray demonstrated a moderate sized distal phalanx exostosis but no evidence of osteomyelitis (see below).
Dr Touzell was concerned about the possibility of osteomyelitis, so an MRI scan and bloods were ordered. Her MRI demonstrated reactive oedema of the distal phalanx with florid subungual granulomatous tissue, but no osteomyelitis.
Mrs C had exhausted her non-operative management options and we were concerned about the risk of chronic infection. We therefore discussed the need for surgical intervention to washout and debride the nail bed, remove the exostosis and take multiple samples to look for growth of microorganisms.
Surgery was uneventful, and multiple samples were taken including the specific request for prolonged fungal cultures.
Fifteen days after surgery, the rare fungal infection 'fusarium' was grown from all samples including bone. This is an incredibly rare fungal infection which normally occurs in immunocompromised hosts (Mrs C was fit and well, did not smoke, had no history of diabetes, steroid use or chemotherapy). Immediate engagement with an Infectious Disease physician was made and Mrs C was commenced on Voriconazole 200mg for three months. We could not find a description in the literature of a fusarium bone infection in an otherwise healthy individual. Mrs C suffered from side effects of this medication including visual disturbance, nausea and dry month.
The medication was ceased after three months but unfortunately Mrs C had a recurrence of her symptoms four weeks after ceasing the medication. She returned to theatre for a repeat debridement and samples again grew fusarium. Her case was discussed at an international microbiology meeting and the consensus was either six months of oral Voriconazole or consider an amputation at the interphalangeal joint. She elective for six months of oral antifungal medication (although the side effects were awful).
Three months after ceasing oral Voriconazole, Mrs C's pain and function has returned to pre-morbid levels. She is able to wear normal shoes, can play sport and do all her regular activities. Her nail has ongoing splintering and deformity (see picture) and may require a total nail ablation in the future. However, at this stage she is happy to be off her anti-fungal treatment and is glad to have avoided an amputation.
Fungal nail infections are very common and are initially best managed in a Primary Care setting. The risk of osteomyelitis of underlying bone, rare infective pathogens or systemic disease is very low, but should be considered in an aggressive infection not responding to standard treatment or in an immunocompromised patient. Where possible, it is recommended fungal scrapings are send for microscopy and prolonged cultures to aid in diagnosis and treatment.