Is Keplex (cephalexin) effective for treating paronychia?

Cephalexin (Keflex) for Paronychia Treatment

Oral antibiotics including cephalexin (Keflex) are recommended for paronychia when there is evidence of infection with discharge, pain, or when topical treatments have failed, particularly for grade 2-3 paronychia. 1

Understanding Paronychia

Paronychia is an inflammatory condition affecting the tissue folds surrounding the fingernail or toenail. It presents as:

• Painful erythematous inflammation with swelling and tenderness of lateral nail folds
• May progress to formation of friable granulation tissue
• Can involve discharge or nail plate separation
• Secondary bacterial infections present in up to 25% of cases

Treatment Algorithm Based on Severity

Grade 1 (Mild) Paronychia

• Nail fold edema or erythema; disruption of cuticle
• First-line treatment:
  • Topical treatments (povidone iodine 2%, topical antibiotics/corticosteroids)
  • Warm water or white vinegar soaks (15 minutes, 3-4 times daily)
  • Continue monitoring for 2 weeks

Grade 2 (Moderate) Paronychia

• Nail fold edema or erythema with pain
• Associated with discharge or nail plate separation
• Limiting instrumental activities of daily living
• Treatment:
  • Topical treatments as above PLUS
  • Oral antibiotics including cephalexin 1
  • Obtain bacterial cultures if infection is suspected
  • Consider dermatology referral if no improvement

Grade 3 (Severe) Paronychia

• Surgical intervention indicated
• Limiting self-care activities of daily living
• Treatment:
  • Oral antibiotics (cephalexin is appropriate)
  • Swab any pus for culture to guide antibiotic selection
  • Consider surgical drainage or partial nail avulsion
  • Dermatology/surgical referral

Evidence for Cephalexin Use

Cephalexin is an appropriate choice for paronychia with suspected bacterial infection because:

1. It provides good coverage against common pathogens in paronychia, particularly gram-positive organisms 2
2. Guidelines recommend oral antibiotics for moderate to severe paronychia, especially when there is evidence of infection 1

Important Clinical Considerations

• Bacterial cultures: Obtain cultures before starting antibiotics when possible, especially in severe cases 1
• Treatment duration: Typically 7-10 days of oral antibiotics
• Adjunctive treatments: Continue topical treatments alongside oral antibiotics
• Preventive measures: Essential to prevent recurrence
  • Keep hands/feet dry
  • Avoid nail trauma/injury
  • Proper nail cutting technique
  • Wear protective gloves when appropriate
  • Moisturize hands/feet regularly

Common Pitfalls to Avoid

1. Treating all paronychia with antibiotics: Mild cases often respond to topical treatments alone
2. Neglecting underlying causes: Chronic paronychia may be related to irritant exposure or systemic conditions
3. Delayed drainage: When abscess is present, drainage is essential alongside antibiotics
4. Overlooking fungal causes: Some cases may have fungal component requiring antifungal therapy
5. Insufficient follow-up: Reassessment after 2 weeks is recommended to evaluate response

Cephalexin is a reasonable antibiotic choice for paronychia with signs of bacterial infection, but treatment should be guided by severity, presence of purulence, and culture results when available.