What are the management options for different types of Sexually Transmitted Infections (STIs)?

Management of Sexually Transmitted Infections

The management of STIs requires pathogen-specific antimicrobial therapy guided by accurate diagnostic testing, with treatment regimens varying by organism and clinical presentation.

Common Bacterial STIs

Gonorrhea and Chlamydia

• Ceftriaxone 125 mg IM plus doxycycline 100 mg orally twice daily for 7 days is the recommended treatment for urethritis and cervicitis when both gonorrhea and chlamydia are suspected 1.
• Nucleic acid amplification tests (NAATs) have high sensitivity (86.1%-100%) and specificity (97.1%-100%) for diagnosis and should be performed from any site of penetration 1, 2.
• Ceftriaxone remains effective for gonorrhea, though antimicrobial resistance increasingly limits oral treatment options 2.
• Doxycycline 100 mg orally twice daily for 7 days is first-line therapy for uncomplicated chlamydia 3, 2.
• Alternative regimens include azithromycin 1 g orally as a single dose, though this is less preferred due to resistance concerns 3, 4.

Syphilis

• Penicillin is the treatment of choice for all stages of syphilis 2.
• Diagnosis relies on sequential serologic testing to detect both treponemal and nontreponemal (antiphospholipid) antibodies 2.
• All patients with suspected STIs should have serologic testing for syphilis at initial presentation 1.

Mycoplasma genitalium

• M. genitalium should NOT be routinely tested or treated, as it is classified as an "equivocal pathogen" with high prevalence in asymptomatic individuals 3.
• Treatment should only be considered when detected in specific clinical syndromes after other causes are excluded 3.
• When treatment is indicated, doxycycline 100 mg orally twice daily for 7 days is first-line, with moxifloxacin as an alternative, though antimicrobial resistance limits options 3, 2.

Ureaplasma Species

• Routine testing and treatment is NOT recommended due to high colonization rates in asymptomatic, sexually active individuals 3.
• Partner treatment should not be automatically initiated, unlike with confirmed STIs 3.

Parasitic STIs

Trichomoniasis

• Trichomoniasis is one of the most frequently diagnosed infections, particularly in women who have been sexually assaulted 1.
• Nitroimidazoles (metronidazole) are effective treatment 2.
• Diagnosis is made by wet mount and culture of vaginal swab specimens 1.
• Approximately 70% of trichomoniasis infections are asymptomatic or minimally symptomatic 2.

Viral STIs

Genital Herpes (HSV)

• No cure is available for genital herpes; treatment focuses on symptom management and reducing transmission 2.
• Acyclovir should be administered to patients with suspected or confirmed HSV infection 1.
• Famciclovir and valacyclovir are alternative antiviral options for episodic or suppressive therapy 5, 6.
• Treatment should be initiated at the first sign or symptom of an episode (tingling, itching, burning, pain) 5, 6.
• Approximately 70% of HSV infections are asymptomatic 2.
• Patients must be counseled that genital herpes is frequently transmitted through asymptomatic viral shedding, even when no lesions are present 5, 6.

Hepatitis B

• Hepatitis B vaccine should be administered for postexposure prophylaxis when indicated 1.
• Serum samples should be collected at initial examination for hepatitis B testing 1.

Ectoparasitic Infections

Pediculosis Pubis (Pubic Lice)

• Permethrin 1% cream rinse applied to affected areas and washed off after 10 minutes is the recommended first-line treatment 1.
• Alternative regimens include pyrethrins with piperonyl butoxide or lindane 1% shampoo (though lindane is not recommended for pregnant/lactating women or children <2 years) 1.
• Bedding and clothing must be decontaminated by machine washing/drying with hot cycle or dry-cleaning, or removed from body contact for at least 72 hours 1.
• Sexual partners within the preceding month should be treated 1.

Scabies

• Permethrin is the preferred treatment for pregnant women, lactating women, infants, and young children 1.
• Lindane should be avoided in these populations due to risk of seizures and aplastic anemia 1.
• Pruritus may persist for several weeks after successful treatment 1, 7.
• Both sexual and close personal/household contacts within the preceding month should be examined and treated 1.

Non-STI Genital Conditions

Vulvovaginal Candidiasis

• When all STI testing is negative and genital itching persists, empiric treatment with topical antifungal therapy (clotrimazole 1% cream or miconazole 2% cream) is the appropriate first-line approach 7.
• Fluconazole 150 mg oral is a convenient alternative, except in pregnancy where only topical azole therapy for 7 days should be used 7.
• Empiric treatment is recommended even without confirmed yeast on microscopy, as microscopy misses 20-50% of cases 7.
• If symptoms persist after 2 weeks of treatment, re-examination and culture for Candida species is indicated 7.

Critical Management Principles

Diagnostic Approach

• NAATs should be performed from all sites of penetration or attempted penetration 1.
• Wet mount examination should be performed when vaginal discharge or malodor is present to evaluate for trichomoniasis, bacterial vaginosis, and yeast 1.
• Approximately 53% to 100% of extragenital gonorrhea and chlamydia infections are asymptomatic, necessitating screening strategies beyond symptom-based testing 2.

Partner Management

• Sexual partners within the preceding month must be examined and treated for confirmed STIs 1.
• Contact tracing of sexual partners is an effective STI prevention intervention 2.

Common Pitfalls

• Antimicrobial agents used for non-gonococcal urethritis may mask or delay symptoms of incubating syphilis; all patients must have serologic testing for syphilis at diagnosis 1, 4.
• Many STIs are asymptomatic (70% for HSV and trichomoniasis, 53-100% for extragenital gonorrhea/chlamydia), requiring screening rather than symptom-based diagnosis alone 2.
• Residual symptoms such as pruritus may persist for weeks after successful treatment and do not necessarily indicate treatment failure 1, 7.

Prevention Strategies

• Patients should avoid contact with lesions or intercourse when lesions/symptoms are present 5, 6.
• Barrier contraception should be promoted as transmission can occur through asymptomatic viral shedding 5, 6, 2.
• Vaccination (hepatitis B, HPV) and preexposure prophylaxis are effective prevention measures 1, 8.