Antibiotic for Paronychia
For acute bacterial paronychia requiring antibiotic therapy, dicloxacillin 500 mg four times daily or cephalexin 500 mg four times daily is the first-line oral treatment for methicillin-susceptible Staphylococcus aureus (MSSA). 1
First-Line Oral Antibiotics for Acute Bacterial Paronychia
For presumed MSSA infection:
- Dicloxacillin 500 mg orally four times daily is the oral agent of choice for methicillin-susceptible strains 1
- Cephalexin 500 mg orally four times daily is an equally effective alternative 1
- Duration: 5-10 days depending on clinical response 1
Alternatives for Penicillin Allergy
For patients with penicillin allergy (excluding immediate hypersensitivity reactions):
- Cephalexin 500 mg orally four times daily can be used if the allergy is not an immediate hypersensitivity reaction 1
- Clindamycin 300-450 mg orally three times daily is appropriate for true penicillin allergy 1
Important caveat: Clindamycin has potential for cross-resistance and emergence of resistance in erythromycin-resistant strains, with inducible resistance possible in MRSA 1
Coverage for Community-Associated MRSA
When CA-MRSA is suspected or confirmed (purulent drainage, failed initial therapy, systemic toxicity, or known MRSA colonization):
Oral options include:
- Clindamycin 300-450 mg orally three times daily 1
- Trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily 1
- Doxycycline or minocycline 100 mg twice daily (avoid in children <8 years) 1
- Linezolid 600 mg twice daily (expensive, reserve for resistant cases) 1
Critical consideration: If streptococcal coverage is also needed alongside MRSA coverage, use clindamycin alone OR combine TMP-SMX or a tetracycline with a beta-lactam (e.g., amoxicillin) 1
Pediatric Dosing
For children requiring systemic antibiotics:
- Dicloxacillin: 25-50 mg/kg/day in 4 divided doses 1
- Cephalexin: 25-50 mg/kg/day in 3-4 divided doses 1
- Clindamycin: 20-30 mg/kg/day in 3 divided doses orally 1
- TMP-SMX: 8-12 mg/kg/day (based on trimethoprim component) in 2 divided doses 1
Common Pitfalls to Avoid
Do not routinely prescribe systemic antibiotics for all paronychia cases - many acute bacterial paronychias respond to incision and drainage alone without antibiotics 2, 3, 4
Antibiotic-resistant acute paronychia may have non-bacterial causes including viral (herpetic whitlow), fungal, drug-induced, or inflammatory etiologies 2, 5
Chronic paronychia (≥6 weeks duration) is typically an irritant dermatitis, not a bacterial infection - systemic antibiotics are ineffective and should not be used routinely 2, 4
Consider culture and sensitivity testing when there is severe infection, systemic illness, failure to respond to initial treatment, or concern for MRSA 1