STDs — Comprehensive

Syphilis, gonorrhea, chlamydia, HSV, HPV, trichomoniasis, chancroid, LGV, granuloma inguinale.

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◆Syphilis stages

•Primary: painless chancre (3–6 weeks after exposure)
•Secondary: maculopapular rash including palms/soles + condylomata lata + mucous patches + generalized LAD; 6 weeks to 6 months
•Latent: asymptomatic; early <1 yr, late >1 yr
•Tertiary: gummas, cardiovascular (aortic aneurysm, AR), neurosyphilis (tabes dorsalis, general paresis, Argyll Robertson pupils)
•Treatment: benzathine penicillin G IM (single dose primary/secondary/early latent; weekly × 3 for late latent/tertiary). Neuro: IV penicillin G × 10–14 days
•Jarisch-Herxheimer reaction: fever/chills/myalgias hours after treatment (endotoxin release)
•Allergic: doxycycline (NOT in pregnancy → desensitize and give penicillin)

•Gonorrhea (N. gonorrhoeae): purulent urethritis/cervicitis; disseminated (DGI) → triad of polyarthralgia + tenosynovitis + pustular rash
•Chlamydia (C. trachomatis): often asymptomatic; cervicitis, urethritis, PID
•Both: NAAT of urine or swab
•Treat empirically for both due to coinfection: ceftriaxone 500 mg IM + doxycycline 100 mg BID × 7 days (or azithromycin 1 g if pregnant)
•PID: fever + lower abd pain + cervical motion tenderness; outpatient ceftriaxone + doxycycline ± metronidazole; admit if pregnant, severe, abscess
•Fitz-Hugh-Curtis: PID + perihepatitis (RUQ pain + 'violin string' adhesions)

•HSV-1 usually oral, HSV-2 usually genital but overlap common
•Painful grouped vesicles on erythematous base; recurrences
•Diagnose: PCR (most sensitive); Tzanck shows multinucleated giant cells
•Treat: acyclovir, valacyclovir, famciclovir
•Pregnancy with active lesions at delivery → C-section (prevent neonatal HSV — devastating)
•Antiviral suppression from 36 weeks if recurrent

•Low-risk (6, 11): condyloma acuminata (genital warts) → imiquimod, podofilox, cryotherapy
•High-risk (16, 18): cervical, anal, oropharyngeal cancer
•Cervical cancer screening: Pap at 21, q3 yr until 30; then Pap + HPV q5 yr or Pap q3 yr until 65
•HPV vaccine (Gardasil 9): all 11–12 yr (can start at 9); up to 26 (or 45 with shared decision-making)

•T. vaginalis: frothy yellow-green discharge + strawberry cervix + motile trichomonads on wet mount
•Treat: metronidazole single dose 2 g (treat partner)
•Avoid alcohol with metronidazole (disulfiram-like reaction)

•Bacterial vaginosis: gray, thin, fishy (KOH 'whiff' test +); clue cells; pH >4.5; metronidazole or clindamycin
•Candida (yeast): thick white 'cottage cheese', itching; pseudohyphae on KOH; fluconazole or topical azole
•Trichomonas: frothy yellow-green, strawberry cervix; metronidazole + treat partner

Cause	Lesion	Lymph nodes	Diagnostic	Treatment
Syphilis (T. pallidum)	PAINLESS firm clean chancre	Painless rubbery LAD	Dark-field, VDRL/RPR (screen), FTA-ABS (confirm)	Benzathine penicillin G
HSV-2	PAINFUL grouped vesicles → ulcers	Tender bilateral LAD	PCR / Tzanck (multinucleated giants)	Acyclovir, valacyclovir, famciclovir
Chancroid (H. ducreyi)	PAINFUL deep ulcer with ragged border	Tender suppurative LAD	Clinical / culture (gram neg coccobacilli)	Azithromycin or ceftriaxone
LGV (C. trachomatis L1–3)	Small painless ulcer → resolves; THEN painful inguinal LAD	Tender 'groove sign' bubo	NAAT / serology	Doxycycline 21 days
Granuloma inguinale (Klebsiella granulomatis)	Painless beefy red ulcer	No LAD typically	Donovan bodies on biopsy	Doxycycline 3+ weeks

◆Painless ulcer + painless LAD = syphilis; PAINFUL ulcer = HSV or chancroid
◆DGI triad: dermatitis + arthritis + tenosynovitis (think gonorrhea)
◆Argyll Robertson pupils accommodate but don't react to light = neurosyphilis ('prostitute's pupil')
◆Pregnancy + syphilis allergy → penicillin desensitization (only option to prevent congenital syphilis)
◆Always treat sexual partners

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