Abstract
Group A Streptococcus commonly colonizes the upper respiratory tract and skin but rarely causes bacterial vaginitis in non-pregnant women. Such an infection may progress to invasive disease via lymphatic spread. We report the case of a woman in her 50s, without significant medical history, who presented with green vaginal discharge and received empirical treatment with intravaginal metronidazole suppositories. Therapy was discontinued after four days due to menstruation, and a subsequent vaginal culture grew Streptococcus pyogenes. Immediately after menstruation, she developed a rapidly enlarging, painful left inguinal mass. Computed tomography revealed marked lymph node enlargement with central low attenuation, consistent with an abscess. Ultrasound-guided aspiration yielded purulent fluid positive for Streptococcus pyogenes. She was treated with intravenous ceftriaxone, followed by oral amoxicillin-clavulanate and then amoxicillin, for a total duration of four weeks, resulting in complete resolution without recurrence. This case highlights that group A Streptococcus can be a potential cause of acute inguinal lymphadenitis in non-pregnant women, particularly after genital symptoms, and emphasizes the importance of early diagnosis via aspiration and culture as well as prompt targeted antibiotic therapy and drainage to prevent invasive progression.