From the Guidelines
Keflex (cephalexin) 500mg three times daily for 5 days is a more appropriate treatment for cellulitis from an insect bite, as it effectively targets the common bacteria that cause skin infections, particularly Staphylococcus and Streptococcus species, and a 5-day course is as effective as a 10-day course if clinical improvement has occurred by 5 days 1. This recommendation is based on the most recent and highest quality study, which suggests that a 5-day course of antimicrobial therapy is sufficient for typical cases of cellulitis without systemic signs of infection 1. Some key points to consider when using Keflex include:
- Take the full course even if symptoms improve early to prevent recurrence or antibiotic resistance
- Monitor for signs of worsening infection such as increasing redness, warmth, swelling, red streaking, fever, or severe pain, which would warrant immediate medical attention
- Keep the area clean, elevate the affected limb when possible to reduce swelling, and apply cool compresses for comfort
- If you have allergies to penicillin or cephalosporins, kidney disease, or if symptoms don't improve within 48-72 hours, consult a healthcare provider
- Drink plenty of water while taking this medication to help prevent kidney issues and take it with food if it causes stomach upset It's also important to note that elevation of the affected area and treatment of predisposing factors, such as edema or underlying cutaneous disorders, are recommended to promote gravity drainage of the edema and inflammatory substances and to reduce the risk of recurrence 1.
From the FDA Drug Label
Patients should be counseled that antibacterial drugs including cephalexin capsules, cephalexin for oral suspension, and cephalexin tablets should only be used to treat bacterial infections.
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued.
The dose of 500mg TID x 10days is not explicitly mentioned in the label for the treatment of a small insect bite with cellulitis.
- The label does mention that cephalexin should be administered with caution in certain conditions, but it does not provide specific guidance for this particular condition.
- The label also emphasizes the importance of using antibacterial drugs only to treat bacterial infections and to complete the full course of therapy as directed. However, the label does not provide information on the specific treatment of small insect bites with cellulitis, therefore The FDA drug label does not answer the question.
From the Research
Treatment of Cellulitis with Keflex
- The use of cephalexin (Keflex) for the treatment of cellulitis, particularly when caused by staphylococcal or streptococcal infections, has been supported by various studies 2, 3.
- A study from 1983 compared cephalexin with dicloxacillin in the treatment of staphylococcal skin and skin structure infections, including cellulitis, and found both antibiotics to be equally effective 2.
- Another study from the same year highlighted the efficacy and usefulness of cephalexin in treating streptococcal and staphylococcal skin infections, including its effectiveness in twice-daily dosages 3.
Dosage and Duration
- The dosage of 500mg TID (three times a day) for 10 days is within the range of commonly prescribed regimens for cephalexin in the treatment of skin and soft tissue infections, including cellulitis 2, 3.
- However, the specific duration and dosage might depend on the severity of the infection and the patient's response to treatment.
Considerations for Insect Bite-Related Cellulitis
- Insect bites can lead to secondary bacterial infections such as cellulitis, and the management of such cases may involve the use of antibiotics like cephalexin 4, 5.
- A study from 2010 suggested that in areas with a high prevalence of community-associated methicillin-resistant Staphylococcus aureus (MRSA) infections, antibiotics with activity against MRSA, such as trimethoprim-sulfamethoxazole and clindamycin, might be preferred over cephalexin for the empiric treatment of outpatients with cellulitis 6.