Ingrowing toenail and nail-fold infection

Ask when pain began, which edge is involved and whether pus, bleeding, fever or redness extends beyond the fold. Establish nail-cutting technique, tight footwear, sport, trauma, previous avulsion, hyperhidrosis and chemical or digging attempts. Record diabetes, neuropathy, arterial disease, renal disease, immune suppression, anticoagulation and antibiotic allergy. An unusual recurrent lesion, pigment or mass needs broader diagnosis.

Remove footwear and inspect both feet. Identify nail curvature, embedded spicule, fold swelling, granulation, drainage and proximal erythema. Palpate for fluctuance and pulp tension and move the interphalangeal joint gently. Document temperature, protective sensation, capillary refill and pedal pulses. Mark spreading cellulitis and examine lymphatics. Avoid probing aggressively under an ischaemic or insensate nail.

Typical ingrowing nail and superficial paronychia are clinical diagnoses. Culture pus when treatment failure, severe infection or unusual exposure makes microbiology useful; superficial colonisation can mislead. Obtain radiographs for suspected foreign body, gas, chronic recurrence or osteomyelitis, recognising early bone infection can be occult. MRI and deep tissue or bone sampling belong to the specialist pathway when osteomyelitis remains consequential.

For mild disease with intact sensation and perfusion, reduce shoe pressure, soak briefly in warm salt water, dry carefully and allow the nail to grow beyond the fold while trimming straight across. A tiny clean cotton or dental-floss lift beneath the edge can separate nail and skin when comfortable, replaced regularly and stopped if pain or inflammation worsens. This is inappropriate for an ischaemic, neuropathic or infected high-risk foot without professional supervision.

A local abscess requires drainage; the clinician lifts or removes the offending lateral nail strip and evacuates pus using digital anaesthesia and tourniquet technique appropriate to perfusion. Send material for culture when severity or recurrence warrants it. Localised infection usually improves with source control and does not need automatic systemic antibiotics. Spreading cellulitis, lymphangitis, systemic illness or high-risk host factors require antibiotics selected by severity, allergy, renal function and local policy.

Recurrent, granulating or moderate-to-severe disease is treated definitively by partial lateral nail avulsion plus matrixectomy. Phenol chemically ablates the lateral matrix after meticulous protection of surrounding skin and haemostasis; sodium hydroxide or surgical matrix excision are alternatives in trained services. Partial treatment preserves nail width and generally recurs less than simple avulsion. Total nail avulsion is not routine because it causes greater morbidity and the whole nail can regrow dystrophic.

After partial avulsion, use a non-adherent dressing and written wound, elevation and footwear advice. Phenol wounds may drain for weeks; increasing pain, redness, malodour, fever or purulence needs review. Nail regrowth takes months, while a successfully ablated strip should not return. Resume sport and tight footwear only when the wound is sufficiently dry and pressure is comfortable.

In diabetes or neuropathy, even modest fold injury can progress without pain, so arrange podiatry or diabetic-foot oversight and assess glucose, pressure and shoes. Poor perfusion increases non-healing and chemical injury risk and may require vascular opinion before matrixectomy. Anticoagulation should not be stopped without a coordinated plan. Pregnancy affects antibiotic and local procedure selection; phenol use and analgesia should follow specialist and product guidance.