Ingrowing toenailsare a common condition that causes pain and disability in the foot. The condition occurs when the nail plate traumatises the nail fold, giving rise to pain, inflammation, or infection.
Treatment largely depends on the type of nail and it is simpler to classify ingrowing toenails into those that occur in normal nails and those occurring in abnormally wide or incurvated edge toenails.
How does an ingrowing toenail occur?
The term ingrowing toenail is used to describe a sharp spike of nail growing into an overlapping nail fold. This condition is caused by a combination of extrinsic and intrinsic factors, such as poorly fitting shoes, improperly trimmed nails, tight socks, excessive sweating, soft tissue abnormalities of the toe, and inherent nail deformity. Normal nails vary greatly in shape, and the nail walls are adaptable to marked curvature of the nails. Ingrowing toenails can occur in the context of normal nail shape
Ingrowing toenails in normal nails tend to present in younger people and are usually a result of improper nail trimming of the lateral edge, which leaves a sharp nail spike that traumatises the nail fold. Evidence from observational studies indicates that the initial treatment should be non-operative , with general instructions in foot care and footwear. The nail should be trimmed at right angles to the long axis of the toe and people can do this at home. A chiropodist can gently retract the nail fold and trim the offending nail spike.
Ingrowing toenails most commonly develop in adults with abnormally wide toenails or those with an incurvated edge. Incurvated (or involuted) toenails can be caused by a bony malformation of the big toe, or by changes in the toenail as a result of irritation and pressure. There is no consensus on standard non-operative treatment of ingrowing toenails in abnormally shaped nails, but failure of non-operative management should lead to consideration of surgical options. Patients are best offered partial nail avulsion with segmental phenol ablation. Phenol has potent antiseptic properties, so the procedure can be carried out even in the presence of infection without risk of wound infection. Patients with severe involuted nails on both the tibial and fibular sides (pincer nails) would be left with a too thin nail after wedge excision and may be better treated with a total nail avulsion.
What are the different types of surgical treatments?
The surgical options consist of procedures that are temporary or permanent.
A Cochrane review (a large study that analyses several papers on the same subject together) has shown that recurrence of symptoms is high after temporary measures, such as simple (or partial) nail avulsion without chemical or surgical ablation, and this may lead to low patient satisfaction. Therefore, we prefer to perform the procedure in selected patients only. However, removal of the nail spike is curative if followed by appropriate aftercare, as detailed above.
A Cochrane review of surgical treatments suggests that simple nail avulsion combined with phenol ablation should be the treatment of choice. A recent clinical trial also showed lower rates of recurrence with partial nail avulsion and phenol ablation compared with partial avulsion with nail matricectomy. The success of phenol matricectomy depends on the use of good quality phenol and satisfactory haemostasis. Individually packed and sealed sterile containers of 90% liquid phenol with appropriately sized cotton tips are now available, and these are safer to use than phenol in brown bottles, which usually come from pharmaceutical suppliers. These individually packed containers also reduce the risk of spillage.
The treatment of ingrowing toenails has traditionally been blighted by high recurrence rates and poor patient satisfaction, but with the increasing use of chemical ablation of the nail matrix in combination with partial nail avulsion reported recurrence rates have decreased. The figure below is a simple approach to the management of this common but poorly treated condition.
(This is an abridged version of a paper my senior colleague and I wrote for the April edition of the British Medical Journal. If you would like a full pdf version of this paper please click on this link.)