What is the treatment for acute paronychia caused by biting fingernails and cuticles?

Treatment of Acute Paronychia from Nail Biting

For acute paronychia caused by biting fingernails and cuticles, start with antiseptic soaks using dilute vinegar (50:50 dilution) or povidone-iodine for 10-15 minutes twice daily, combined with topical 2% povidone-iodine applied directly to the affected area twice daily. 1

Initial Management Algorithm

Mild Cases (Grade 1: Nail fold edema or erythema without pain)

• Apply topical 2% povidone-iodine twice daily to the affected nail fold 2, 1
• Combine with topical antibiotics/corticosteroids (such as a mid to high potency topical steroid ointment twice daily) to reduce inflammation 2, 1
• Implement antiseptic soaks with dilute vinegar (50:50 dilution) or povidone-iodine for 10-15 minutes twice daily 1
• Reassess after 2 weeks; if no improvement or worsening, escalate treatment 2, 1

Moderate Cases (Grade 2: Pain with discharge or nail plate separation)

• Continue topical 2% povidone-iodine and topical corticosteroids/antibiotics 2
• Add oral antibiotics if there is evidence of bacterial infection 2, 1
• Obtain bacterial/viral/fungal cultures if infection is suspected, as secondary bacterial or mycological superinfections occur in up to 25% of cases 2, 3
• If initial oral antibiotic (such as cephalexin) fails, switch to sulfamethoxazole-trimethoprim (Bactrim) for broader coverage including MRSA 4
• Reassess after 2 weeks; if no improvement, proceed to more aggressive interventions 2, 4

Severe Cases (Grade 3: Abscess formation or limiting self-care activities)

• Obtain cultures before initiating treatment 2, 4
• Continue topical 2% povidone-iodine, topical corticosteroids/antibiotics, AND oral antibiotics 2
• Perform surgical drainage if abscess is present 2, 3
• Consider partial nail avulsion for refractory cases 2
• Consider silver nitrate chemical cauterization for excessive granulation tissue 1

Critical Prevention Measures to Address the Root Cause

Since this is caused by nail biting, patient education is paramount to prevent recurrence: 3

• Immediately stop biting nails and cuticles - this is the primary causative factor 2
• Trim nails straight across and not too short 2, 1
• Apply emollients daily to cuticles and periungual tissues to maintain the protective barrier 2, 1
• Avoid repeated trauma and friction to the nail folds 2
• Wear protective gloves during activities involving water or chemicals 1, 4

Common Pitfalls to Avoid

• Do not use systemic antibiotics routinely unless there is clear evidence of bacterial infection or abscess formation 5, 3
• Do not assume all paronychia is infectious - acute paronychia from nail biting often has an inflammatory component that responds to topical corticosteroids 3
• Do not overlook fungal colonization - obtain cultures if the condition doesn't respond to initial treatment, as fungi are present in up to 25% of cases 2, 5
• Do not perform aggressive surgical interventions prematurely - most cases respond to conservative management with antiseptic soaks and topical therapy 3, 6

When to Escalate Care

• If no improvement after 2 weeks of appropriate treatment, consider referral to dermatology or hand surgery 4, 7
• If osteomyelitis is suspected (severe pain, bone tenderness, systemic symptoms), obtain imaging and refer urgently 8
• If recurrent despite behavioral modification, consider underlying conditions such as contact dermatitis or immunocompromise 3