From the Research
The recommended duration of doxycycline therapy for an infected cyst is at least 28 days, as a treatment duration of 28 days or longer has been shown to reduce recurrences 1. The standard adult dosage is 100 mg taken orally twice daily. For children over 8 years old and weighing less than 45 kg, the dose is 2-4 mg/kg/day divided into two doses. Doxycycline should be taken with a full glass of water, and patients should remain upright for at least 30 minutes after taking it to prevent esophageal irritation. Some key points to consider when treating infected cysts include:
- The choice of antibiotic may not be as crucial as the duration of therapy, as the modality of initial antibiotic therapy was not associated with treatment failure 1.
- The penetration of antibiotics into the cyst fluid can vary widely between drugs, with trimethoprim and ciprofloxacin having the highest penetration ratios amongst the antibiotics tested 2.
- Patients should complete the full course of antibiotics even if symptoms improve before completion to prevent recurrence and antibiotic resistance.
- If there's no improvement after 48-72 hours of treatment, reevaluation may be necessary as the infection might require drainage or different antibiotic coverage. It's also important to note that some studies have shown that a significant proportion of inflamed epidermal inclusion cysts may not have positive cultures, which could impact the decision to use empiric antibiotics 3. However, in the context of renal cyst infections, the use of prolonged antibiotic therapy has been shown to be effective in reducing recurrences 1.