What are the diagnostic and treatment options for a patient, particularly those with a history of diabetes or poor circulation, presenting with an ingrown nail?

Diagnostics and Treatment of Ingrown Toenail

Immediate Diagnostic Approach

In patients with diabetes or poor circulation, ingrown toenails require immediate evaluation by a trained healthcare professional, as they represent a pre-ulcerative sign that strongly predicts progression to foot ulceration with significant morbidity and mortality risk. 1, 2

Clinical Assessment

• Examine for signs of infection including purulent drainage, significant erythema extending beyond the nail fold, cellulitis, abscess formation, warmth, and systemic symptoms (fever, elevated WBC) 1, 2
• Assess vascular status by palpating foot pulses and checking for signs of peripheral artery disease, as ischemia dramatically worsens outcomes 1
• Test for peripheral neuropathy using monofilament or tuning fork examination to determine loss of protective sensation 1
• Probe the depth of any associated wound—if bone is visible or palpable with a sterile probe, suspect osteomyelitis 1

Risk Stratification for Diabetic Patients

• Use the IWGDF risk classification system to categorize patients: Risk 0 (no neuropathy), Risk 1 (neuropathy alone), Risk 2 (neuropathy plus deformity or PAD), Risk 3 (prior ulcer/amputation) 1, 3
• Patients in Risk categories 2-3 require urgent specialist referral due to high amputation risk 1

Treatment Algorithm

For Non-Infected Ingrown Toenails (Conservative Management)

Conservative treatment is appropriate only for mild cases without infection in patients without diabetes or vascular disease. 4, 5

• Warm antiseptic soaks with dilute vinegar (50:50 dilution) or 2% povidone-iodine for 10-15 minutes twice daily 2, 6
• Gutter splinting by placing cotton wisps or dental floss under the ingrown nail edge to separate it from the lateral fold, providing immediate pain relief 4, 5
• Resin splint application attached to the lateral nail edge can achieve pain relief within one week with only 8.2% recurrence rate 7
• Correct footwear and avoid tight shoes that compress the toes 1

For Infected Ingrown Toenails (Antibiotic Therapy)

Confirm infection is present before prescribing antibiotics—look for purulent drainage, significant cellulitis, or abscess formation. 2

• First-line antibiotic: Cephalexin 500 mg orally every 12 hours for 10 days as it provides coverage for Staphylococcus aureus, the most common pathogen 2
• Alternative for penicillin allergy: Clindamycin 300 mg three times daily for 10 days 2
• If MRSA suspected or treatment failure: Switch to sulfamethoxazole-trimethoprim (Bactrim) 2
• For mild-moderate paronychia: Augmentin 500 mg/125 mg every 12 hours 2
• Obtain bacterial cultures before starting antibiotics in severe cases or treatment failures to guide therapy 2

Surgical Management

Partial nail avulsion combined with phenolization is the most effective surgical approach, superior to conservative treatment for preventing recurrence. 4, 5

• Partial nail avulsion removes the ingrown lateral edge of the nail plate 4, 5
• Chemical matricectomy with phenol prevents recurrence more effectively than surgical excision alone, though it carries slightly increased infection risk 4
• Complete nail excision is reserved for recurrent cases or when partial avulsion fails 4

Special Considerations for High-Risk Patients

Diabetic Patients

Diabetic patients with ingrown toenails must be treated by a trained foot care professional immediately—do not attempt home remedies or delay treatment. 1, 2

• Drain blisters when necessary using sterile technique, as blisters are pre-ulcerative signs 1, 3
• Ensure proper off-loading and prescribe appropriate therapeutic footwear 1, 3
• Educate patients to inspect feet daily, wash feet daily with careful drying between toes, and contact healthcare immediately if new lesions develop 1, 3
• Never walk barefoot, in socks only, or in thin-soled slippers whether at home or outside 1

Patients with Peripheral Artery Disease

If the limb appears ischemic (absent pulses, ABI <0.9, toe pressure <30 mmHg), refer urgently to vascular surgery before infection worsens. 1

• Early revascularization is preferable to prolonged antibiotic therapy in severely infected ischemic feet 1
• Do not delay debridement of necrotic infected tissue while awaiting revascularization 1
• Prescribe aggressive cardiovascular risk management including smoking cessation, statin therapy, and low-dose aspirin or clopidogrel 1

Critical Pitfalls to Avoid

• Never prescribe prophylactic antibiotics for uninfected ingrown toenails—this promotes antibiotic resistance without benefit 3
• Do not delay treatment in diabetic patients—ingrown nails can rapidly progress to serious ulceration and infection 2
• Consider fungal superinfection if not responding to antibiotics—up to 25% of cases develop secondary fungal infections requiring antifungal treatment 2
• Do not rely solely on absence of fever or leukocytosis to rule out deep infection in diabetic patients 1
• Avoid using chemical agents or plasters for callus removal in at-risk patients 1

Prevention of Recurrence

• Teach proper nail trimming technique: cut toenails straight across, not curved 1
• Apply emollients to lubricate dry skin but avoid between toes 1
• Ensure follow-up until complete resolution and monitor for recurrence 1
• Address contributing factors including hyperhidrosis, onychomycosis, and improper footwear 4, 5