From the Guidelines
For uncomplicated cellulitis of the lower leg, the best oral antibiotics are typically cephalexin (Keflex) 500 mg four times daily or dicloxacillin 500 mg four times daily for 5-7 days, as recommended by the most recent guidelines 1. These antibiotics effectively target the most common causative organisms, which are Streptococcus species and Staphylococcus aureus. Some key points to consider when treating cellulitis include:
- Elevating the affected limb to reduce swelling
- Marking the border of the infection to monitor progression
- Ensuring adequate hydration
- Following up within 48-72 hours to assess response to therapy Alternatively, clindamycin 300-450 mg four times daily can be used for patients with penicillin allergies. If community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is suspected, trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily or doxycycline 100 mg twice daily are appropriate choices, as suggested by the guidelines 1. It's also important to note that the duration of antibiotic therapy should be 5-7 days, but treatment should be extended if the infection has not improved within this time period, as recommended by the guidelines 1. Overall, the choice of antibiotic and duration of therapy should be individualized based on the patient's specific needs and circumstances, and guided by the most recent and highest quality evidence 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 staphylococci Anaerobes: Serious skin and soft tissue infections; Streptococci: Serious skin and soft tissue infections. Staphylococci: Serious skin and soft tissue infections.
The best oral antibiotics for treating uncomplicated cellulitis of the lower leg include clindamycin.
- Clindamycin is effective against streptococci and staphylococci, which are common causes of cellulitis.
- The dosage and administration of clindamycin should be determined by the clinical and bacteriological response of the patient, as well as the overall condition of the patient 2.
- Dicloxacillin may also be considered, but its use is generally limited to mild to moderate infections, and it is best absorbed when taken on an empty stomach 3.
From the Research
Oral Antibiotics for Uncomplicated Cellulitis of the Lower Leg
The treatment of uncomplicated cellulitis of the lower leg typically involves oral antibiotics that target Streptococcus and methicillin-sensitive Staphylococcus aureus 4. The choice of antibiotic may depend on various factors, including the presence of risk factors for methicillin-resistant S. aureus (MRSA) and the patient's medical history.
Recommended Antibiotics
- Levofloxacin: A study published in 2004 found that 5 days of levofloxacin therapy was as effective as 10 days of therapy for patients with uncomplicated cellulitis 5.
- Cephalexin: A review published in 2013 suggested that cephalexin plus trimethoprim-sulfamethoxazole may be effective for treating uncomplicated cellulitis, although the role of CA-MRSA in nonpurulent cellulitis is less clear 6.
- Penicillin V: A review published in 2023 recommended penicillin V as the preferred antibiotic for prevention of recurrent cellulitis, although other antibiotics may be considered in cases of β-lactam allergy, intolerance, or failure 7.
Duration of Treatment
- 5 days: A study published in 2004 found that 5 days of levofloxacin therapy was sufficient for patients with uncomplicated cellulitis, with no significant difference in clinical outcome compared to 10 days of therapy 5.
- Extension of treatment: Treatment may need to be extended if symptoms are not improved after 5 days, and addressing predisposing factors can minimize the risk of recurrence 4.
Special Considerations
- Risk factors for MRSA: Patients with specific risk factors, such as athletes, children, men who have sex with men, prisoners, military recruits, residents of long-term care facilities, those with prior MRSA exposure, and intravenous drug users, may require expanded coverage for MRSA 4.
- Multidrug-resistant organisms: In cases of multidrug-resistant organisms, such as Streptococcus pseudoporcinus, alternative antibiotics may be necessary, and treatment may need to be individualized based on antibiogram results 8.