Antibiotic Selection for Uncomplicated Paronychia with Cellulitis
For uncomplicated paronychia presenting as cellulitis without abscess in a patient with nail-biting history, cephalexin is the preferred choice over Augmentin, as beta-lactam monotherapy targeting streptococci and methicillin-sensitive Staphylococcus aureus is the standard of care for typical nonpurulent cellulitis and is successful in 96% of cases. 1
First-Line Treatment Rationale
Cephalexin 500 mg orally every 6 hours for 5 days is the guideline-recommended first-line agent for typical nonpurulent cellulitis, providing excellent coverage against beta-hemolytic streptococci (especially Streptococcus pyogenes) and methicillin-sensitive Staphylococcus aureus 1, 2
The Infectious Diseases Society of America explicitly recommends beta-lactam monotherapy as standard of care for uncomplicated cellulitis, with a 96% success rate confirming that MRSA coverage is usually unnecessary 1
Acute paronychia is caused by polymicrobial infections after the protective nail barrier has been breached, typically involving skin flora that respond well to standard beta-lactam coverage 3
Why Not Augmentin?
Augmentin (amoxicillin-clavulanate) provides unnecessarily broad coverage for this clinical scenario 1
While Augmentin is listed as an acceptable option for cellulitis, it is specifically recommended for bite-associated cellulitis (875/125 mg twice daily) where polymicrobial oral flora coverage is needed 1, 2
The clavulanic acid component adds coverage against beta-lactamase-producing organisms, which is not routinely necessary for typical paronychia without specific risk factors 2
Augmentin should be considered preferentially only in specific situations: recent amoxicillin use, traumatic wounds, infections not responding to simple beta-lactams, or cellulitis with purulent drainage 2
Treatment Duration and Monitoring
Treat for exactly 5 days if clinical improvement occurs; extend only if symptoms have not improved within this timeframe 1, 2
Five-day courses are as effective as 10-day courses for uncomplicated cellulitis, based on high-quality randomized controlled trial evidence 1
Reassess within 24-48 hours to verify clinical response, as treatment failure rates of 21% have been reported with some oral regimens 1
When MRSA Coverage Would Be Needed (Not Applicable Here)
MRSA coverage is NOT needed for typical nonpurulent paronychia/cellulitis, as MRSA is an uncommon cause even in high-prevalence settings 1, 2
Add MRSA-active antibiotics ONLY when specific risk factors are present: penetrating trauma, injection drug use, purulent drainage or exudate, evidence of MRSA infection elsewhere, or systemic inflammatory response syndrome 1, 2
Nail-biting alone does not constitute an indication for MRSA coverage 3, 4
Critical Caveat About Abscess
If any abscess is present, drainage is the primary treatment, not antibiotics alone 3, 5, 6
A prospective study of 46 patients demonstrated that surgical excision of uncomplicated paronychia or felon without antibiotic coverage gives excellent results with only rare recurrence (45/46 cases healed without complications) 6
Oral antibiotics are usually not needed if adequate drainage is achieved unless the patient is immunocompromised or a severe infection is present 3, 5
Adjunctive Measures
Elevate the affected extremity to promote gravity drainage of edema and inflammatory substances 1, 2
Address the underlying nail-biting habit through patient education, as this is paramount to reduce recurrence of acute paronychia 3
Warm soaks with or without Burow solution or 1% acetic acid can be used as adjunctive treatment 3
Common Pitfall to Avoid
Do not reflexively prescribe Augmentin for all skin infections simply because it has "broader coverage"—this represents overtreatment, increases antibiotic resistance, and provides no additional benefit in typical cases 1
Do not use combination therapy (such as adding trimethoprim-sulfamethoxazole to a beta-lactam) when monotherapy is appropriate, as this increases adverse effects without improving outcomes 1