Should a patient with a positive test for both pharyngeal Chlamydia (Chlamydia trachomatis) and streptococcal pharyngitis (strep throat) be treated for both conditions?

From the Guidelines

Yes, you should treat both pharyngeal chlamydia and strep throat when a patient tests positive for both infections. For pharyngeal chlamydia, prescribe doxycycline 100mg twice daily for 7 days, as recommended by the Centers for Disease Control and Prevention 1. For strep throat (Group A Streptococcus), prescribe penicillin V 500mg twice daily for 10 days, or amoxicillin 500mg three times daily for 10 days, as recommended by the Infectious Diseases Society of America 1. If the patient has a penicillin allergy, azithromycin 500mg once daily for 5 days can be used for strep throat.

Key Considerations

• These infections require different antibiotic treatments as they are caused by different pathogens - chlamydia is caused by the bacterium Chlamydia trachomatis while strep throat is caused by Streptococcus pyogenes.
• Leaving either infection untreated could lead to complications, such as rheumatic fever or post-streptococcal glomerulonephritis from untreated strep throat, and spread of the infection to sexual partners and potentially more serious complications from untreated chlamydia.
• Ensure the patient completes the full course of both antibiotics, even if symptoms improve before completion, as recommended by the Infectious Diseases Society of America 1.

Treatment Regimens

• Pharyngeal chlamydia: doxycycline 100mg twice daily for 7 days 1
• Strep throat (Group A Streptococcus):
  • Penicillin V 500mg twice daily for 10 days 1
  • Amoxicillin 500mg three times daily for 10 days 1
  • Azithromycin 500mg once daily for 5 days (for patients with penicillin allergy)

Patient Education

• Patients should be instructed to refer their sex partners for evaluation and treatment, as recommended by the Centers for Disease Control and Prevention 1.
• Patients should be educated on the importance of completing the full course of antibiotics, even if symptoms improve before completion.

From the FDA Drug Label

Erythromycin tablets are indicated in the treatment of infections caused by susceptible strains of the designated microorganisms in the diseases listed below: Upper respiratory tract infections of mild to moderate degree caused by Streptococcus pyogenes; Erythromycins tablets are indicated for treatment of the following infections caused by Chlamydia trachomatis: conjunctivitis of the newborn, pneumonia of infancy, and urogenital infections during pregnancy When tetracyclines are contraindicated or not tolerated, erythromycin tablets are indicated for the treatment of uncomplicated urethral, endocervical, or rectal infections in adults due to Chlamydia trachomatis.

Treatment for both conditions is recommended. The patient should be treated for streptococcal pharyngitis with erythromycin, as it is indicated for the treatment of upper respiratory tract infections caused by Streptococcus pyogenes. Additionally, the patient should be treated for Chlamydia trachomatis, as erythromycin is indicated for the treatment of infections caused by this microorganism, although the label does not specifically mention pharyngeal Chlamydia, it does mention other forms of Chlamydia trachomatis infections. 2

From the Research

Treatment for Pharyngeal Chlamydia and Streptococcal Pharyngitis

• A patient with a positive test for both pharyngeal Chlamydia (Chlamydia trachomatis) and streptococcal pharyngitis (strep throat) should be treated for both conditions, as untreated infections can lead to complications 3.
• For streptococcal pharyngitis, penicillin V for 10 days is the standard therapy, but alternative treatments such as azithromycin can be effective in cases of penicillin hypersensitivity or nonadherence to the 10-day penicillin regimen 4, 5.
• Azithromycin has been shown to be effective in treating streptococcal pharyngitis, with a total dose of 60 mg/kg given over 3 or 5 days providing the best rate of GABHS eradication 4.
• For pharyngeal Chlamydia, the preferred treatment is a seven-day course of doxycycline, 100 mg taken by mouth twice per day 3.
• It is essential to note that the treatment of pharyngeal Chlamydia and streptococcal pharyngitis should be guided by the results of diagnostic tests and the patient's medical history, and that antibiotic treatment should only be used when indicated by a positive test result 6, 5.

Considerations for Treatment

• The choice of antibiotic treatment for streptococcal pharyngitis should be based on the patient's susceptibility to the antibiotic, as well as the potential for resistance 4, 7.
• The treatment of pharyngeal Chlamydia and streptococcal pharyngitis should be tailored to the individual patient's needs, taking into account factors such as age, medical history, and potential allergies or interactions with other medications 3.
• Follow-up evaluations should be performed to ensure that the infections have been adequately treated and to monitor for potential complications 7.