What is the appropriate treatment for Group A streptococcal pharyngitis in a pregnant woman?

Treatment of Streptococcal Pharyngitis in Pregnancy

Penicillin V 250 mg orally three to four times daily for 10 days or amoxicillin 500 mg orally twice daily for 10 days are the drugs of choice for treating Group A streptococcal pharyngitis in pregnant women, with proven safety across all trimesters and zero documented resistance worldwide. 1, 2

First-Line Oral Regimens

• Penicillin V remains the gold standard: 250 mg orally three to four times daily for 10 days provides effective bacterial eradication with an excellent safety profile throughout pregnancy. 1

• Amoxicillin offers equivalent efficacy with simpler dosing: 500 mg orally twice daily for 10 days is often preferred due to better palatability and improved adherence. 1

• Both agents have zero documented resistance among Group A Streptococcus isolates worldwide, ensuring reliable bacterial eradication. 1, 2

Intramuscular Alternative

• Benzathine penicillin G 1.2 million units as a single intramuscular injection is recommended when oral adherence is uncertain or when a single-dose regimen is preferred. 1

• This single injection provides adequate tissue levels for 10 days and eliminates compliance concerns. 1

Mandatory Treatment Duration

• A complete 10-day course is essential to achieve maximal pharyngeal eradication of Group A Streptococcus and to prevent acute rheumatic fever, even if symptoms resolve within 3–4 days. 1, 2

• Shortening the course by even a few days markedly increases treatment-failure rates and the risk of acute rheumatic fever. 1, 2

• Therapy can be safely initiated up to 9 days after symptom onset and still effectively prevent acute rheumatic fever. 1

Management of Penicillin Allergy in Pregnancy

Non-Immediate (Delayed) Penicillin Reactions

• First-generation cephalosporins are safe and preferred: cephalexin 500 mg orally twice daily or cefadroxil 1 gram orally once daily for 10 days. 1, 2

• The cross-reactivity risk with first-generation cephalosporins is only 0.1% in patients with delayed, mild penicillin reactions (e.g., rash occurring >1 hour after exposure). 2

Immediate/Anaphylactic Penicillin Reactions

• All β-lactam antibiotics must be avoided due to up to 10% cross-reactivity risk with cephalosporins in patients with immediate hypersensitivity (anaphylaxis, angioedema, urticaria within 1 hour). 1, 2

• Erythromycin (non-estolate formulations) 250–500 mg orally every 6–12 hours for 10 days is an acceptable macrolide alternative for pregnant women with anaphylactic penicillin allergy. 1

• Erythromycin estolate is absolutely contraindicated in pregnancy due to increased risk of cholestatic hepatitis. 1

Diagnostic Confirmation Before Treatment

• Rapid antigen detection testing (RADT) or throat culture should be performed before initiating antibiotics, as clinical features alone cannot reliably differentiate Group A Streptococcus from viral pharyngitis. 1

• If clinical suspicion is high based on fever, tonsillar exudate, and cervical lymphadenitis, therapy can be initiated while awaiting culture results, but antibiotics should be discontinued if testing is negative. 1

Primary Treatment Goals

• Prevention of acute rheumatic fever is the primary goal—antibiotics initiated up to 9 days after symptom onset remain effective in preventing this complication. 1, 2

• Rapid symptom resolution (shortening illness by 1–2 days), prevention of suppurative complications (peritonsillar abscess), and reduction of transmission to close contacts are additional benefits. 1, 2

Critical Pitfalls to Avoid

• Do not use erythromycin estolate in pregnant women—only non-estolate formulations (erythromycin base, ethylsuccinate, or stearate) are safe. 1

• Do not prescribe cephalosporins to pregnant women with immediate/anaphylactic penicillin reactions due to the ~10% cross-reactivity risk. 1, 2

• Do not shorten the antibiotic course below 10 days—this dramatically increases treatment failure and rheumatic fever risk, even if symptoms improve rapidly. 1, 2

• Do not prescribe azithromycin or clarithromycin as first-line agents—macrolide resistance among Group A Streptococcus ranges from 5–8% in the United States and varies geographically, making them less reliable than penicillin or erythromycin. 3, 2

Adjunctive Symptomatic Care

• Acetaminophen or ibuprofen should be offered for moderate-to-severe sore throat, fever, or systemic discomfort. 2

• Corticosteroids are not recommended as adjunctive therapy for streptococcal pharyngitis in pregnancy. 3, 2