Sexually Transmitted Infections

Sexually Transmitted Infections

Sexually Transmitted Infections

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Syphilis & Ulcers - Ulcerative Villains

  • Syphilis (Treponema pallidum): Spirochete.
    • Primary: Painless, indurated chancre. Darkfield microscopy.
    • Secondary: Maculopapular rash (palms/soles), condyloma lata.
    • Latent: Asymptomatic, seropositive.
    • Tertiary: Gummas, neurosyphilis (tabes dorsalis), aortitis.
    • Congenital: Hutchinson's triad.
    • Dx: VDRL/RPR (screen/monitor); TPPA/FTA-ABS (confirm).
    • Rx: Benzathine Penicillin G 2.4 MU IM. ⚠️ Jarisch-Herxheimer.
  • Other Genital Ulcers: 📌 Painful: Chancroid, Herpes.
    • Chancroid (H. ducreyi): Painful, soft ulcer; painful bubo. "School of fish".
    • Genital Herpes (HSV): Painful vesicles → ulcers. Multinucleated giant cells (Tzanck).
    • LGV (C. trachomatis L1-L3): Evanescent painless ulcer; painful lymphadenopathy ("groove sign").
    • Donovanosis (K. granulomatis): Painless, beefy-red, progressive ulcer. Donovan bodies. Donovan bodies in granuloma inguinale

⭐ Neurosyphilis can present with Argyll Robertson pupils (accommodate but don't react to light).

Gono & Chlamydia - Discharge Dilemmas

  • Gonorrhea (N. gonorrhoeae):
    • Gram-negative diplococci (GNDC).
    • Men: Purulent urethral discharge, dysuria.
    • Women: Often asymptomatic; cervicitis, PID.
    • Complications: Disseminated Gonococcal Infection (DGI) (arthritis-dermatitis syndrome), ophthalmia neonatorum.
    • Dx: NAAT, Gram stain (PMNs + GNDC).
    • Rx: Ceftriaxone 500mg IM + Azithromycin 1g PO.
  • Chlamydia (C. trachomatis D-K):
    • Obligate intracellular bacteria.
    • Men: Mucoid/watery discharge, dysuria; often asymptomatic.
    • Women: Often asymptomatic; cervicitis, PID.
    • Complications: Reactive Arthritis (Reiter's: "can't see, can't pee, can't climb a tree" 📌), infertility. Neonatal conjunctivitis/pneumonia.
    • Dx: NAAT (gold standard).
    • Rx: Azithromycin 1g PO or Doxycycline 100mg BID x 7 days.
  • Key Points:
    • Co-infection is common; consider dual therapy.
    • NAAT is the preferred diagnostic test for both.

    Chlamydia trachomatis is the most common bacterial STI globally. Gram stain of Neisseria gonorrhoeae in neutrophilsoka

Viral STIs - Viral Vagabonds

  • Herpes Simplex Virus (HSV): Genital Herpes
    • Types: HSV-1 (often oral), HSV-2 (genital predominance).
    • Clinical: Painful vesicles → ulcers. Recurrent.
    • Diagnosis: Tzanck smear (multinucleated giant cells), PCR (gold standard).
    • Treatment: Acyclovir, Valacyclovir.
    • Latency: Sensory ganglia (📌 HSV-S-Sacral/Sensory).
  • Human Papillomavirus (HPV):
    • Types:
      • Low-risk: 6, 11 (Condyloma acuminata/genital warts).
      • High-risk: 16, 18, 31, 33 (Cervical, anogenital, oropharyngeal cancers).
    • Diagnosis: Clinical (warts), Pap smear (koilocytes), HPV DNA.

    ⭐ Koilocytes (cells with perinuclear halo & wrinkled nucleus) are characteristic cytopathic effects of HPV seen on Pap smears.

    • Prevention: HPV Vaccine (e.g., Gardasil 9).
  • Hepatitis B Virus (HBV):
    • Transmission: Sexual, blood, perinatal.
    • Sequelae: Chronic hepatitis, cirrhosis, Hepatocellular Carcinoma (HCC).
    • Key markers: HBsAg (infection), Anti-HBs (immunity).
  • Molluscum Contagiosum Virus (MCV): (Poxvirus)
    • Clinical: Pearly, umbilicated papules.
    • Diagnosis: Clinical; Henderson-Paterson bodies (intracytoplasmic inclusions). Koilocyte in Pap smear
  • HIV: (Covered in detail separately)
    • Targets CD4+ T-cells. Sexual transmission is a major route.

Other STIs & Syndromic Rx - Critters & Kits

  • Protozoal & Ectoparasites ("Critters")

    • Trichomonas vaginalis (Protozoa): Frothy, yellow-green discharge. Strawberry cervix. Wet mount: motile flagellates. Rx: Metronidazole 2g PO single (or Tinidazole 2g). Treat partner.
    • Sarcoptes scabiei (Scabies): Intense pruritus (night), burrows. Rx: Permethrin 5% cream.
    • Phthirus pubis (Pediculosis): Pubic lice, nits. Rx: Permethrin 1% lotion.
  • Syndromic Management (NACO "Kits")

    • Approach based on clinical syndromes, not etiology. Uses pre-packaged, color-coded kits.

    ⭐ NACO Kit 1 (Grey): Urethral Discharge, Cervicitis, Anorectal Discharge - Azithromycin 1g + Cefixime 400mg (all PO).

    • Other common kits:
      • Kit 2 (Green): Vaginal Discharge - Secnidazole 2g + Fluconazole 150mg (all PO).
      • Kit 3 (White): Non-herpetic GUD - Benzathine Penicillin 2.4MU IM + Azithromycin 1g PO.
      • Kit 6 (Red): PID - Cefixime + Doxycycline + Metronidazole (all PO; Doxy/Metro for 14 days).

NACO STI Treatment Kits by Clinical Condition

High-Yield Points - ⚡ Biggest Takeaways

  • Syphilis: Painless chancre (1°), condyloma lata (2°); screen with VDRL/RPR. Jarisch-Herxheimer reaction.
  • Gonorrhea: Gram-negative diplococci, purulent discharge, arthritis (DGI). Treat with Ceftriaxone.
  • Chlamydia: Most common bacterial STI, often asymptomatic. Azithromycin/Doxycycline. LGV by L-serovars.
  • Genital Herpes (HSV-2): Painful vesicles, recurrences. Acyclovir. Tzanck: multinucleated giant cells.
  • HPV: Condyloma acuminata (types 6, 11); cervical cancer link (types 16, 18). Vaccine available.
  • Trichomoniasis: Motile protozoa, strawberry cervix, frothy discharge. Treat with Metronidazole.

Practice Questions: Sexually Transmitted Infections

Test your understanding with these related questions

A sexually active lady came with profuse yellowish frothy discharge with intense itching. On local examination of the vagina a 'strawberry' like cervix is revealed. What condition she is likely suffering from?

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Flashcards: Sexually Transmitted Infections

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The bugs that are associated with Guillain-Barre Syndrome are ICE MyCZ:I_____CMVEBVMycoplasma PneumoniaeCampylobacterZika

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The bugs that are associated with Guillain-Barre Syndrome are ICE MyCZ:I_____CMVEBVMycoplasma PneumoniaeCampylobacterZika

nfluenzavirus

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