From the Guidelines
For cellulitis around an ingrown toenail, I recommend cephalexin 500 mg orally four times daily (every 6 hours) for 5-7 days for adults with normal renal function, as supported by the Infectious Diseases Society of America guidelines 1. Children should receive 25-50 mg/kg/day divided into four doses. This antibiotic effectively targets the most common causative organisms in skin infections, particularly Staphylococcus aureus and Streptococcus species. Some key points to consider when treating cellulitis include:
- Take the full course even if symptoms improve before completion.
- Take with food if stomach upset occurs.
- While using antibiotics, keep the area clean, soak the foot in warm water with Epsom salt 2-3 times daily, and avoid tight footwear.
- If symptoms worsen, develop fever above 101°F, notice increasing redness spreading beyond the toe, or see pus formation, seek immediate medical attention as this may indicate treatment failure or need for surgical intervention.
- Cephalexin works by disrupting bacterial cell wall synthesis, but it won't be effective against MRSA or certain resistant organisms, so follow-up is important if improvement isn't seen within 48-72 hours 1. It's also important to note that the treatment of cellulitis may vary depending on the severity of the infection and the presence of any underlying conditions, and that antibiotic therapy should be guided by culture results and susceptibility testing when possible 1.
From the FDA Drug Label
For the following infections, a dosage of 500 mg may be administered every 12 hours: streptococcal pharyngitis, skin and skin structure infections, and uncomplicated cystitis in patients over 15 years of age. The usual adult dose is 250 mg every 6 hours For more severe infections or those caused by less susceptible organisms, larger doses may be needed
The recommended dose of cephalexin for cellulitis, a type of skin and skin structure infection, is 500 mg every 12 hours for adults. However, for more severe infections, a larger dose may be needed. Considering the condition is painful, it may be classified as a more severe infection. Therefore, the dose may need to be adjusted accordingly, but based on the label, a dose of 500 mg every 12 hours can be considered as a starting point 2.
From the Research
Cephalexin Dosage for Cellulitis
- The recommended dosage of cephalexin for cellulitis is not explicitly stated in the provided studies.
- However, according to the study 3, cephalexin was administered at a dose of 500 mg four times daily for 7 days in patients with uncomplicated cellulitis.
- It is essential to note that the dosage of cephalexin may vary depending on the severity of the infection, patient age, and other factors, and should be determined by a healthcare professional.
Considerations for Cellulitis Treatment
- The study 4 suggests that an antistaphylococcal oral antibiotic is the preferred treatment for nonbullous and bullous impetigo, and a therapeutic agent that is effective against both S aureus and streptococci is appropriate for most cases of cellulitis.
- The study 5 emphasizes the importance of thorough history and clinical examination to narrow the differential diagnosis of cellulitis and minimize unnecessary hospitalization.
- The study 6 found that there is no evidence to support the superiority of any one antibiotic over another, and antibiotics with activity against methicillin-resistant Staphylococcus aureus did not add an advantage.
Antibiotic Selection
- The study 7 suggests that cephalexin is comparable to erythromycin, clindamycin, dicloxacillin, cloxacillin, and other cephalosporins in the treatment of streptococcal and staphylococcal infections.
- The study 3 compared the use of cephalexin plus trimethoprim-sulfamethoxazole vs cephalexin alone in patients with uncomplicated cellulitis, and found that the use of cephalexin plus trimethoprim-sulfamethoxazole did not result in higher rates of clinical resolution of cellulitis in the per-protocol analysis.