In 2023, 48.2% of reported cases of sexually transmitted infections (STIs) were among adolescents and young adults (AYA) between the ages of 15-24.1 Chlamydia is often asymptomatic in AYA and requires screening to detect its high prevalence.1,2 There is emerging data that pre- and post- exposure prophylactic doxycycline (doxy-PrEP, doxy-PEP) may reduce the likelihood of contracting STIs, specifically chlamydia.3

A 16-year-old presented with her mother to the outpatient ambulatory clinic with 3 months of irregular menses. The patient’s history included major depressive disorder with recent self-harm, and use of alcohol and marijuana multiple times/week. No other history. During a confidential history without the parent, the patient endorsed she recently began engaging in vaginal sex with her cisgender boyfriend, only intermittently using condoms. She often was sexually active while under the influence of alcohol/marijuana. The patient requested provision of confidential contraception. After discussing risks, benefits, alternatives and anticipatory guidance she chose a contraceptive patch.

At follow up 4 months later, she reported a positive chlamydia test from vaginal and oral swabs 2 weeks prior, obtained at another clinic. She was treated appropriately there. Since our initial visit, the patient had become sexually active with multiple other cisgender male partners using condoms intermittently. The patient met with the social worker who provided appropriate resources after there were indications of sexual coercion and transactional sexual activity, though without patient confirmation. She met CDC criteria for HIV PrEP. With her ongoing high-risk sexual behavior and recent chlamydia diagnosis with a high risk of reinfection, she received confidential prescriptions and counseling for HIV PrEP and doxy-PEP.4

Given the patient's sexual activity with multiple partners, recent chlamydia diagnosis, and limited disclosure to her mother (her transportation provider), alongside her lack of a driver's license, poor support system, and limited resources, doxy-PEP was discussed. The indications, benefits, risks, and alternatives were conveyed (see box 1). The patient opted for doxy-PEP, valuing fewer STI testing appointments and partner notifications over potential inefficacy risks.3 This situation is increasingly common, and underscores the need for trauma-informed, harm-reduction approaches to adolescent sexual health. Interventions like doxy-PEP can empower patients, enhance autonomy, and improve outcomes. Further research is needed to confirm efficacy in patients engaging in vaginal sex.3