From the Guidelines
For non-purulent cellulitis, the recommended antibiotics include a 5- to 6-day course of antibiotics active against streptococci, such as dicloxacillin 500 mg orally four times daily, cephalexin 500 mg orally four times daily, or clindamycin 300-450 mg orally three times daily. First-line therapy typically targets Streptococcus and methicillin-sensitive Staphylococcus aureus (MSSA), as these are the most common causative organisms 1. If MRSA is suspected based on risk factors or local prevalence, consider trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily or doxycycline 100 mg twice daily. For patients with penicillin allergies, clindamycin or levofloxacin 750 mg daily are appropriate alternatives. Treatment duration should be extended if symptoms persist beyond 5 days. Patients should elevate the affected area, monitor for spreading redness, increasing pain, fever, or systemic symptoms, and seek immediate medical attention if these occur.
Some key points to consider when treating non-purulent cellulitis include:
- The use of antibiotics active against streptococci, such as cephalosporins, penicillins, or clindamycin, is recommended for most cases of non-purulent cellulitis 1.
- The duration of antibiotic therapy should be 5-6 days, but may need to be extended if symptoms persist beyond this time period 1.
- Patients with risk factors for MRSA, such as penetrating trauma or evidence of MRSA infection elsewhere, may require additional antimicrobial coverage 1.
- Elevation of the affected area and treatment of predisposing factors, such as edema or underlying cutaneous disorders, are also recommended 1.
It's worth noting that the most recent and highest quality study, published in 2021, recommends a 5- to 6-day course of antibiotics active against streptococci for non-purulent cellulitis 1. This study provides the most up-to-date guidance on the treatment of non-purulent cellulitis and should be prioritized when making treatment decisions.
From the FDA Drug Label
Prescribing dicloxacillin sodium capsules in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
The non-purulent antibiotic for cellulitis mentioned is dicloxacillin sodium capsules 2.
- Key points:
- Dicloxacillin is a penicillinase-resistant penicillin.
- It should only be used to treat bacterial infections.
- The patient should be instructed to take the entire course of therapy prescribed, even if fever and other symptoms have stopped.
From the Research
Non-Purulent Antibiotics for Cellulitis
- The use of antibiotics for non-purulent cellulitis is primarily directed against β-hemolytic streptococci, with options including penicillin, amoxicillin, and cephalexin 3.
- A study comparing cephalexin plus trimethoprim-sulfamethoxazole versus cephalexin alone for treatment of uncomplicated cellulitis found no significant difference in treatment success rates, suggesting that empirical coverage of CA-MRSA is not necessary for non-purulent cellulitis 4, 5.
- Another study found that trimethoprim-sulfamethoxazole had a higher treatment success rate than cephalexin for empiric therapy of cellulitis, but this was in a setting with a high prevalence of community-associated MRSA infections 6.
- For non-purulent cellulitis, antibiotic prophylaxis can be effective in preventing recurrence, especially when risk factors such as chronic edema, venous disease, and obesity are managed 7.
- The majority of non-purulent, uncomplicated cases of cellulitis are caused by β-hemolytic streptococci or methicillin-sensitive Staphylococcus aureus, and targeted coverage with oral antibiotics such as penicillin, amoxicillin, and cephalexin is sufficient 3.
Key Findings
- CA-MRSA is not a primary cause of non-purulent cellulitis, and empirical coverage is not recommended 4, 3.
- Antibiotics with activity against β-hemolytic streptococci, such as penicillin, amoxicillin, and cephalexin, are preferred for non-purulent cellulitis 3.
- Trimethoprim-sulfamethoxazole may be considered in areas with high prevalence of community-associated MRSA infections 6.