What antibiotics are recommended for treating paronychia?

Antibiotic Treatment for Paronychia

For acute bacterial paronychia, oral antibiotics should only be prescribed after adequate drainage is achieved, with first-line agents being dicloxacillin (250 mg 4 times daily) or cephalexin (250 mg 4 times daily) targeting Staphylococcus aureus, unless the patient is immunocompromised or has severe infection. 1, 2

Treatment Algorithm Based on Severity

Grade 1 Paronychia (Mild: nail fold edema or erythema, cuticle disruption)

• Start with conservative management—do not use systemic antibiotics 1, 3
• Apply topical povidone iodine 2% daily combined with topical antibiotics and corticosteroids 4, 1
• Implement warm water soaks for 15 minutes, 3-4 times daily, or white vinegar soaks for 15 minutes daily 1
• Reassess after 2 weeks; if no improvement, escalate to Grade 2 treatment 4

Grade 2 Paronychia (Moderate: nail fold edema/erythema with pain, discharge, or nail plate separation)

• Obtain bacterial/viral/fungal cultures if infection is suspected 4, 1
• Continue topical povidone iodine 2% and apply mid-to-high potency topical corticosteroid ointment to nail folds twice daily 1, 2
• Initiate oral antibiotics only if infection is confirmed or strongly suspected: 1
  • First-line: Dicloxacillin 250 mg 4 times daily or cephalexin 250 mg 4 times daily 2
  • Penicillin allergy: Clindamycin 300-400 mg 3 times daily 2
  • Suspected MRSA: Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily or doxycycline 100 mg twice daily 2
• Reassess after 2 weeks 4

Grade 3 Paronychia (Severe: surgical intervention indicated, limiting self-care activities)

• Interrupt causative medications until Grade 0-1 if drug-induced 4
• Obtain cultures and initiate culture-guided antibiotic therapy 2
• Perform surgical drainage if abscess is present—this is mandatory and oral antibiotics alone are insufficient 3, 5
• Consider partial nail avulsion for refractory cases 4

Special Clinical Scenarios

Candida-Associated Paronychia (up to 25% of cases develop secondary fungal superinfection)

• First-line: Topical imidazole lotions for superficial Candida infection 1
• For nail plate invasion or severe cases: Oral itraconazole 200 mg daily or pulse therapy (400 mg daily for 1 week each month) for minimum 4 weeks for fingernails, 12 weeks for toenails 4, 1
• Fluconazole (50 mg daily or 300 mg weekly) is an alternative if itraconazole is contraindicated 4, 2

Drug-Induced Paronychia (EGFR inhibitors, MEK inhibitors, taxanes)

• This is NOT primarily infectious—it results from altered keratinocyte differentiation and apoptosis 4
• Microbiological analysis shows mixed flora (72% Gram-positive, 23% Gram-negative, 5% Candida), but these are often colonizers rather than primary pathogens 6
• Avoid routine systemic antibiotics unless secondary bacterial infection is confirmed 7
• If empirical oral antibiotics are needed: oral cephalosporins, ciprofloxacin, levofloxacin, or moxifloxacin have high activity against isolated organisms 6
• Consider topical timolol 0.5% gel twice daily under occlusion for 1 month for complete clearance 4

Critical Pitfalls to Avoid

• Do not prescribe systemic antibiotics for paronychia associated with ingrown toenails unless proven infection exists—the antibiotics are ineffective against the mechanical cause 7, 5
• Do not use systemic antibiotics routinely for chronic paronychia, which is primarily an irritant contact dermatitis, not an infection 3, 7
• Ensure adequate surgical drainage before antibiotics—antibiotics without drainage will fail 3, 5
• Recognize that cephalosporins are contraindicated in patients with immediate penicillin hypersensitivity (urticaria, angioedema, bronchospasm, anaphylaxis) 8
• Adjust therapy based on culture results and local resistance patterns in treatment failures 2

Prevention Strategies

• Keep hands and feet dry, avoid prolonged soaking in soapy water, and wear protective gloves during wet work 1
• Trim nails straight across, avoid cutting too short or nail biting, and apply emollients daily to cuticles 1
• Avoid repeated trauma to the nail unit 2