What is the best antibiotic for treating paronychia?

Best Antibiotic for Paronychia

For acute bacterial paronychia, dicloxacillin (250 mg 4 times per day) or cephalexin (250 mg 4 times per day) are the first-line antibiotics of choice, targeting the most common causative organism Staphylococcus aureus. 1

Types of Paronychia and Appropriate Treatment

Acute Bacterial Paronychia

• Acute paronychia is primarily caused by bacterial infection, with Staphylococcus aureus being the most common pathogen, followed by Streptococcus species 2, 3
• First-line oral antibiotic options include:
  • Dicloxacillin: 250 mg 4 times daily (adults) 1
  • Cephalexin: 250 mg 4 times daily (adults) 1
• For penicillin-allergic patients:
  • Clindamycin: 300-400 mg 3 times daily (adults) 1
• For suspected MRSA infection:
  • Trimethoprim-sulfamethoxazole: 1-2 double-strength tablets twice daily 1
  • Doxycycline: 100 mg twice daily (not recommended for children under 8 years) 1

When to Use Antibiotics

• Oral antibiotics are indicated when there is:
  • Evidence of spreading infection (cellulitis) 3
  • Systemic symptoms (fever) 3
  • Failure of local measures and drainage 3
  • Immunocompromised status 3
• Antibiotics are often unnecessary if adequate drainage of an abscess is achieved in immunocompetent patients 3

Chronic Paronychia

• Chronic paronychia (symptoms lasting >6 weeks) is primarily an irritant dermatitis rather than an infection 3
• Topical treatments are preferred over oral antibiotics:
  • Topical steroids (mid to high potency) to reduce inflammation 4
  • Topical povidone iodine 2% twice daily has shown benefit in controlled studies 1
  • Topical antifungals if fungal infection is confirmed 1
• If fungal infection with Candida is confirmed:
  • Itraconazole should be considered first-line treatment 1
  • Fluconazole can be used as an alternative if contraindications to itraconazole exist 1

Special Considerations

Culture-Guided Therapy

• Obtain bacterial/viral/fungal cultures if infection is suspected, especially in cases of:
  • Treatment failure 1
  • Unusual presentation 5
  • Immunocompromised patients 3
• Adjust antibiotic therapy based on culture results and sensitivity patterns 6

Adjunctive Measures

• Warm soaks with or without Burow solution or 1% acetic acid 3
• Antiseptic soaks with dilute vinegar (50:50 dilution) or 2% povidone-iodine for 10-15 minutes twice daily 4
• Drainage of any abscess is essential for treatment success 3, 7
• Avoid repeated trauma to the nail unit and wear protective gloves when working with water or chemicals 4

Common Pitfalls

• Overuse of systemic antibiotics when not indicated, particularly in chronic paronychia 2, 3
• Failure to address underlying causes in chronic paronychia (e.g., occupational exposures, contact irritants) 3
• Inadequate drainage of abscesses, which is often more important than antibiotic therapy 3, 7
• Misdiagnosis of fungal paronychia as bacterial, leading to inappropriate antibiotic use 1, 5
• Failure to recognize drug-induced paronychia, particularly from EGFR inhibitors in cancer patients, which requires different management 1

Remember that treatment duration should be 7-10 days for acute bacterial paronychia, and longer courses are rarely necessary if adequate drainage and local care are provided 1, 3.