What antibiotic is used to treat paronychia (nail bed infection)?

From the Guidelines

For a nail bed infection, the recommended first-line antibiotic treatment is typically oral cephalexin, given its recent endorsement as a first-choice option by the WHO Expert Committee in 2021 1. This recommendation is based on the principle of parsimony and the effectiveness of cephalexin against common causes of nail bed infections, such as Staphylococcus aureus and Streptococcus species. The dosage for cephalexin is usually 500 mg four times daily for 7-10 days. Key considerations for treatment include:

• The causative pathogens, with Staphylococcus aureus and Streptococcus species being the most common
• The severity of the infection, with more severe cases potentially requiring cultures to guide antibiotic selection
• Patient allergies, particularly to penicillin, in which case clindamycin 300-450 mg four times daily is an appropriate alternative 1 Additional management strategies include keeping the affected area clean and dry, elevating the extremity when possible to reduce swelling, and using warm soaks 3-4 times daily to improve circulation and healing. It is crucial to monitor the infection's response to treatment and seek immediate medical attention if the infection worsens or if systemic symptoms such as fever develop despite 48 hours of antibiotic treatment, as surgical drainage may be necessary. The choice of antibiotic should always prioritize the most recent and highest quality evidence, with a focus on minimizing morbidity, mortality, and improving quality of life 1.

From the FDA Drug Label

Clindamycin is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. Clindamycin is also indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylocci Serious skin and soft tissue infections

• Clindamycin can be used to treat serious skin and soft tissue infections caused by susceptible bacteria, which may include nail bed infections.
• However, the label does not explicitly mention nail bed infections as an indication.
• The decision to use clindamycin for a nail bed infection should be based on bacteriologic studies to determine the causative organisms and their susceptibility to clindamycin 2.

From the Research

Antibiotic Treatment for Nail Bed Infection

• The use of antibiotics for nail bed infections, such as paronychia, depends on the cause of the infection 3.
• Acute paronychia is mainly due to bacterial infection, with Staphylococcus aureus or Streptococcus being common causes, while chronic paronychia is often the result of numerous conditions, including the disappearance of the cuticle 3.
• Systemic antibiotics are not recommended unless infection is proven, as they are often ineffective and can contribute to antibiotic resistance 3.
• For bacterial skin and skin structure infections, including paronychia, empiric antimicrobial therapy should be directed at the most likely pathogens, such as Staphylococcus aureus or Streptococcus pyogenes 4.
• Oral antimicrobial agents, such as beta-lactamase-stable penicillins, macrolides, and cephalosporins, may be considered for treatment 4.
• A study found that amoxicillin was effective in treating group A Streptococcal paronychia in children, with favorable outcomes in all cases without surgical procedures 5.
• However, cases due to Staphylococcus aureus infection often required surgery, highlighting the importance of proper diagnosis and treatment 5.