Multisystem Processes & Disorders

Gonorrhea and chlamydia: testing, treatment, and partner notification

Clinical Overview and When to Suspect Gonorrhea/Chlamydia

— Highest incidence: sexually active persons <25 yrs, MSM, persons with new/multiple partners, inconsistent condom use, prior STI, transactional sex, incarceration history

— Rising rates of drug-resistant GC (especially decreased cephalosporin susceptibility) drove the 2021 CDC update to high-dose ceftriaxone monotherapy

— Men: urethral discharge, dysuria, testicular pain (epididymitis)

— Women: mucopurulent cervicitis, intermenstrual/postcoital bleeding, dyspareunia, lower abdominal pain (PID), dysuria with sterile pyuria

— Both sexes: anorectal pain/discharge/tenesmus (proctitis), pharyngitis, conjunctivitis, reactive arthritis (GC > CT)

— All sexually active women <25 annually; ≥25 if risk factors

— All pregnant women <25 or with risk factors at first prenatal visit; retest in 3rd trimester if high-risk

— MSM: at least annually at all exposed sites (urethral, rectal, pharyngeal) — every 3–6 months if high-risk or HIV+

— Persons with HIV: at entry to care, then annually

— Men who have sex with women only: routine screening not recommended by USPSTF (insufficient evidence) — screen if symptoms or high-risk setting

Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) are the two most commonly reported notifiable STIs in the US, frequently co-infect, and share testing, treatment, and partner-notification logic — but regimens diverge.

Epidemiology drivers

When to suspect — symptomatic

When to screen asymptomatic (USPSTF / CDC)

Board pearl: Asymptomatic infection is the rule, not the exception — >70% of women and ~50% of men with CT are asymptomatic. This is why screening, not symptom-based testing, drives population control.

Step 3 management: A 22-year-old woman presenting for contraception counseling with a new partner deserves GC/CT NAAT regardless of symptoms — bundle it with the visit.

Presentation Patterns and Key History

— GC: purulent, copious yellow-green discharge, onset 2–7 days post-exposure, marked dysuria

— CT/NGU: mucoid or watery scant discharge, onset 1–3 weeks, milder dysuria

— Overlap is substantial — do not treat empirically based on discharge character alone when NAAT is available

— Mucopurulent endocervical discharge, easily induced cervical bleeding ("strawberry cervix" classically trichomonas, but friability is shared)

— Often asymptomatic — discovered on screening or partner notification

— Lower abdominal/pelvic pain, fever, cervical motion/adnexal/uterine tenderness

— Fitz-Hugh–Curtis: perihepatitis with RUQ pain, "violin-string" adhesions

— Rectal: often asymptomatic; proctitis in receptive anal intercourse — discharge, tenesmus, hematochezia

— Pharyngeal: usually asymptomatic; reservoir for transmission and resistance

— Conjunctival: hyperacute purulent conjunctivitis (GC) — ophthalmologic emergency

— Triad: migratory polyarthralgia, tenosynovitis, pustular/vesiculopustular skin lesions (arthritis-dermatitis syndrome)

— Or purulent monoarthritis; associated with terminal complement deficiency (C5–C9)

— Post-CT (>GC): asymmetric oligoarthritis, conjunctivitis/uveitis, urethritis; HLA-B27+

— Partners (number, gender), Practices (oral/vaginal/anal, insertive/receptive), Protection, Past STIs, Pregnancy/prevention plans

— Last exposure date, symptoms in partner(s), prior treatment, allergies

Urethritis (men)

Cervicitis (women)

Upper tract (women) — PID

Extragenital

Disseminated gonococcal infection (DGI)

Reactive arthritis (Reiter)

Key history to obtain ("5 P's")

Key distinction: GC = purulent and fast; CT = mild and slow — but always test both because co-infection occurs in ~20–40% and empiric clinical distinction is unreliable.

Board pearl: A young woman with "UTI symptoms" but sterile pyuria on urinalysis and negative urine culture — think CT urethritis. Reflex to NAAT.

Physical Exam Findings and Site-Specific Assessment

— Vital signs: usually normal in uncomplicated infection; fever and tachycardia suggest PID, epididymo-orchitis, DGI, or tubo-ovarian abscess (TOA)

— Skin survey: pustular/hemorrhagic acral lesions of DGI; keratoderma blennorrhagicum and circinate balanitis in reactive arthritis

— Inspect meatus for discharge — milk urethra if not spontaneously visible

— Palpate scrotum: epididymal tenderness (posterior testicle) with intact cremasteric reflex and positive Prehn sign (pain relief with elevation) suggests epididymitis over torsion

— Inguinal lymphadenopathy

— Speculum: mucopurulent cervical os discharge, cervical friability, ectropion edema

— Bimanual: cervical motion tenderness, uterine tenderness, or adnexal tenderness = minimum CDC criteria for PID — treat empirically

— Adnexal fullness/mass → suspect TOA, get imaging

— External inspection, anoscopy in symptomatic MSM: erythema, mucopus, friability

— Adult hyperacute conjunctivitis with copious pus → GC until proven otherwise; risk of corneal perforation within 24 h

— Neonatal ophthalmia neonatorum: GC days 2–5, CT days 5–14

— DGI: warm, swollen knee/wrist/ankle, tenosynovitis over dorsum of hand/wrist is a giveaway

— Hypotension, peritonitis, rebound tenderness → ruptured TOA or septic arthritis with sepsis

General

Male GU exam

Female pelvic exam

Anorectal

Pharyngeal — often unremarkable; injected posterior pharynx ± exudate

Ocular

Joint

Hemodynamic red flags requiring escalation

CCS pearl: For a febrile young woman with pelvic pain and CMT, on the case simulator: order CBC, hCG, GC/CT NAAT, HIV, syphilis, pelvic ultrasound if TOA suspected, then start ceftriaxone + doxycycline + metronidazole without waiting for results. Document the pelvic exam.

Board pearl: Tenosynovitis + pustular skin lesions + polyarthralgia in a young sexually active patient = DGI — blood cultures, synovial fluid, and mucosal NAATs from all exposed sites (mucosal yield > blood).

Diagnostic Workup — Initial Testing (NAAT) and Specimen Selection

— Women: vaginal swab (clinician- or self-collected) is preferred — equivalent to endocervical, better than urine

— Men: first-catch urine is preferred for urethral infection (≥20 mL, no cleaning, ≥1 h since last void)

— Rectal and pharyngeal: swab those sites directly — urine misses extragenital infection in ~70% of MSM with rectal/pharyngeal GC/CT

— Conjunctival: swab conjunctiva

— Not routinely needed for uncomplicated urogenital GC or CT treated with first-line regimens

— TOC indicated:

— Pharyngeal GC (lower cure rates) — NAAT at 7–14 days

— Pregnancy (both GC and CT) — NAAT at 4 weeks post-treatment

— Persistent symptoms or suspected nonadherence/reinfection

— Alternative regimens used

— NAAT before 2–3 weeks may detect nonviable nucleic acid → false positive

— All treated patients: retest at 3 months regardless of partner treatment status

— HIV (4th-gen Ag/Ab), syphilis (RPR or treponemal), trichomonas in women, hepatitis B/C based on risk

— Pregnancy test in women of reproductive age

— Urinalysis: pyuria supports urethritis but does not distinguish GC vs CT

— Gram stain of urethral discharge in men: >2 PMNs/hpf with intracellular gram-negative diplococci = GC (sens >95% in symptomatic men, poor in women and asymptomatic)

NAAT is the test of choice for both GC and CT at all anatomic sites — high sensitivity (>95%) and specificity, replaces culture for routine diagnosis

Specimen by site (CDC/FDA-cleared)

Test of cure (TOC)

Retesting (different from TOC — screens for reinfection)

Co-testing on the same visit (CDC standard bundle)

Adjuncts

Board pearl: Missed extragenital GC/CT is the #1 reason for "treatment failure" in MSM — always swab the throat and rectum if exposure history is present. Urine alone is inadequate.

Step 3 management: Ordering urine NAAT only in a sexually active MSM patient is a wrong answer — pick the option that includes 3-site testing.

Diagnostic Workup — Confirmatory, Resistance, and Complication Studies

— Still indicated for suspected treatment failure, DGI, neonatal infection, sexual assault evaluation, and antimicrobial susceptibility testing

— GC culture: chocolate agar / Thayer-Martin, requires CO₂, transport rapidly — do not refrigerate

— CT culture is technically demanding and rarely used clinically; NAAT suffices

— CDC's Gonococcal Isolate Surveillance Project (GISP) monitors resistance — drives empiric regimen updates

— Emerging concern: ceftriaxone-resistant GC (sporadic global cases); fluoroquinolone resistance widespread (~30%) → FQs no longer recommended

— Painless genital ulcer → tender inguinal "buboes" with groove sign → late proctocolitis with strictures (MSM, HIV+)

— Diagnosis: CT NAAT positive plus LGV-specific molecular typing (send to public health lab)

— Treatment: doxycycline 100 mg BID × 21 days (not the 7-day CT regimen)

— Pelvic ultrasound: thick-walled tubal complex, free fluid, TOA

— CBC, CRP/ESR (nonspecific), hCG (rule out ectopic), urinalysis

— Scrotal Doppler if torsion considered (especially age <35 sexually active or any prepubertal/elderly without STI risk)

— STI etiology in <35 (GC/CT), enteric (E. coli) in older men or insertive anal sex

— Blood cultures (positive in ~50% of bacteremic form), synovial fluid Gram stain/culture, NAAT of cervix/urethra/rectum/pharynx (higher yield than blood)

— Echocardiogram if murmur — rule out endocarditis

— Screen for terminal complement deficiency if recurrent neisserial infection — CH50

Culture — when and why

Antimicrobial resistance surveillance

Lymphogranuloma venereum (LGV) — CT serovars L1–L3

PID/TOA workup

Epididymitis workup

DGI workup

Key distinction: A positive CT NAAT from the rectum in an MSM patient with proctitis and tender inguinal nodes warrants LGV-directed 21-day doxycycline, not the standard 7-day course — call the lab for genotyping.

Board pearl: Recurrent DGI or meningococcal disease → check CH50 → terminal complement (C5–C9) deficiency.

Risk Stratification and Management Logic

— Test → presumptive treat at point of care if high pretest probability or follow-up unreliable → notify partners → retest at 3 months

— Empiric ("expedited") treatment at the visit is appropriate for: symptomatic urethritis/cervicitis/PID/epididymitis, known exposure to confirmed case, sexual assault prophylaxis

— Uncomplicated: urethritis, cervicitis, proctitis, pharyngitis — outpatient oral/IM single-visit therapy

— Complicated: PID, epididymo-orchitis, DGI, conjunctivitis, neonatal, pregnancy — extended or parenteral therapy ± admission

— Pregnancy, failed outpatient therapy, inability to tolerate PO, severe illness (high fever, vomiting), TOA, surgical emergency not excluded (appendicitis)

— Otherwise outpatient regimens have equivalent outcomes

— Pre-2007: fluoroquinolones — abandoned

— 2010–2020: ceftriaxone 250 mg + azithromycin 1 g (dual therapy)

— 2021 CDC update: ceftriaxone 500 mg IM × 1 monotherapy for uncomplicated GC (1 g if ≥150 kg); doxycycline 100 mg BID × 7 days for CT (replaces azithromycin as first-line)

— Rationale: macrolide resistance in GC and superior doxycycline efficacy for rectal CT

— If CT not ruled out, treat empirically for CT when treating GC — give ceftriaxone + doxycycline

— Pure CT (GC NAAT negative): doxycycline alone

— All sexual partners within prior 60 days (or most recent partner if last contact >60 days) should be evaluated and treated

— Expedited Partner Therapy (EPT): prescribe/dispense meds for partner without exam — legal in most US states; check local statute

Decision framework

Uncomplicated vs complicated

Outpatient vs inpatient PID (CDC criteria for admission)

Resistance-driven treatment evolution

Co-infection logic

Partner management

Step 3 management: A 19-year-old with confirmed urogenital GC by NAAT, CT pending, no symptoms of PID → ceftriaxone 500 mg IM + doxycycline 100 mg PO BID × 7 days, EPT for partner, retest in 3 months.

Board pearl: Single-dose azithromycin is no longer first-line for CT — pick doxycycline on the exam.

Pharmacotherapy — First-Line Regimens (2021 CDC Update)

— Ceftriaxone 500 mg IM × 1 (1 g if weight ≥150 kg)

— If chlamydia not excluded: add doxycycline 100 mg PO BID × 7 days

— Alternative if ceftriaxone unavailable: gentamicin 240 mg IM + azithromycin 2 g PO × 1, or cefixime 800 mg PO × 1 (cefixime not reliable for pharyngeal — TOC needed)

— Ceftriaxone 500 mg IM × 1 — TOC NAAT at 7–14 days (lower cure rates at this site)

— Cefixime not recommended

— Doxycycline 100 mg PO BID × 7 days (first-line — superior for rectal CT)

— Alternatives: azithromycin 1 g PO × 1 (acceptable when adherence concerns), levofloxacin 500 mg daily × 7 days

— Doxycycline 100 mg BID × 21 days

— Ceftriaxone 500 mg IM × 1 + doxycycline 100 mg BID × 14 days + metronidazole 500 mg BID × 14 days

— Metronidazole covers anaerobes/BV — now routinely included

— Ceftriaxone 1 g IV q24h + doxycycline 100 mg IV/PO BID + metronidazole 500 mg IV/PO BID

— Alternative: cefotetan/cefoxitin + doxycycline

— Transition to oral after 24–48 h of clinical improvement to complete 14 days

— Likely STI (<35 or insertive anal sex): ceftriaxone 500 mg IM + doxycycline 100 mg BID × 10 days

— Likely enteric: levofloxacin 500 mg daily × 10 days

— Both possible: ceftriaxone + levofloxacin × 10 days

— Ceftriaxone 1 g IV/IM q24h × ≥7 days (≥10–14 if meningitis/endocarditis: 2 g q12–24h, longer duration)

— Treat empirically for CT co-infection

— Ceftriaxone 1 g IM × 1 + saline lavage; ophthalmology consult

— Abstain for 7 days after single-dose therapy or until completion of 7-day regimen and all partners treated and asymptomatic

Uncomplicated gonorrhea (urethra, cervix, rectum)

Pharyngeal gonorrhea

Uncomplicated chlamydia

LGV (CT L1–L3)

PID — outpatient

PID — inpatient

Epididymitis

DGI

Conjunctivitis (adult GC)

Counseling at prescription

Board pearl: Ceftriaxone dose doubled in 2021 from 250 → 500 mg; azithromycin dropped as routine GC co-therapy; doxycycline replaced azithromycin as first-line CT.

Allergy Management, Resistance, and Pharmacology Pearls

— True IgE-mediated penicillin allergy: cross-reactivity with ceftriaxone is <2% — most patients can receive it safely

— Severe/anaphylactic reaction to any cephalosporin → alternative regimen

— Alternative for GC if cephalosporin contraindicated: gentamicin 240 mg IM × 1 + azithromycin 2 g PO × 1 (cure ~99% urogenital, lower for pharyngeal)

— Consider allergy consultation for desensitization in pregnancy or DGI where alternatives are weak

— Pregnancy or breastfeeding: azithromycin 1 g PO × 1 for CT

— Doxycycline intolerance: azithromycin 1 g, or levofloxacin 500 mg × 7 days

— Doxycycline: take with full glass of water, sit upright 30 min (pill esophagitis), avoid cation co-administration (Ca, Mg, Al antacids, iron, dairy within 2 h), photosensitivity — sunscreen; not in pregnancy/<8 yrs (teeth staining)

— Ceftriaxone IM: dilute with 1% lidocaine to reduce injection pain (no epinephrine); avoid IV ceftriaxone with calcium-containing solutions in neonates

— Azithromycin: QT prolongation — caution with other QT drugs

— Fluoroquinolones: tendinopathy, aortic dissection, dysglycemia, CNS effects — reserve

— Report suspected treatment failures to local health department; obtain culture with susceptibility before re-treating

— Persistent symptoms after correct first-line therapy → consider reinfection (most common), Mycoplasma genitalium, trichomonas, or true resistance

— 2024 CDC guidance: doxycycline 200 mg within 72 h after condomless sex for MSM and transgender women with ≥1 bacterial STI in past 12 months

— Reduces CT, syphilis, and (modestly) GC — not recommended for cisgender women (insufficient evidence)

Cephalosporin allergy

Doxycycline alternatives

Drug interactions and counseling

Resistance surveillance

Doxycycline post-exposure prophylaxis (doxy-PEP)

Step 3 management: Patient returns 2 weeks after treatment with recurrent urethral symptoms and negative GC/CT NAAT → think Mycoplasma genitalium → resistance-guided therapy (doxycycline lead-in then moxifloxacin or azithromycin based on macrolide-resistance assay).

Board pearl: Reinfection > resistance — always reassess partner treatment and new exposures before escalating antibiotics.

Special Populations — Elderly, Renal, and Hepatic Considerations

— Sexually active adults ≥60 are an underscreened group; rising STI rates in long-term care and assisted living

— Postmenopausal vaginal atrophy increases mucosal susceptibility

— Symptoms often atypical or attributed to UTI — maintain a low threshold for NAAT in any new dysuria or vaginal/penile discharge in older adults

— Take a sexual history at the Medicare Annual Wellness Visit

— Ceftriaxone: no renal dose adjustment (biliary excretion predominant) — full 500 mg IM dose

— Doxycycline: no renal dose adjustment — preferred tetracycline in CKD (unlike tetracycline, which is contraindicated)

— Azithromycin: no adjustment

— Gentamicin (alternative GC regimen): single 240 mg IM dose is well tolerated even in CKD; avoid repeated dosing without levels

— Levofloxacin: dose-adjust for CrCl <50

— Ceftriaxone: caution in combined hepatic + renal dysfunction; can rarely cause biliary sludging/pseudolithiasis

— Doxycycline: hepatically metabolized but generally safe; avoid in severe hepatic failure

— Erythromycin (rare alternative): hepatotoxicity, avoid

— Doxycycline ↓ warfarin metabolism → INR rise; monitor closely

— Azithromycin + amiodarone/sotalol/methadone → QT prolongation

— Ceftriaxone + warfarin → INR rise

— Capacity to consent to testing and treatment; involve appropriate surrogates only when capacity is genuinely impaired

— Confidentiality remains paramount — do not disclose STI status to family without consent

Older adults — underrecognized population

Renal impairment

Hepatic impairment

Drug interactions in polypharmacy elders

Functional and cognitive issues

Board pearl: A 72-year-old widower in assisted living with new dysuria and pyuria but negative urine culture — ask the sexual history and order GC/CT NAAT. Age is not protective.

Step 3 management: No renal dose adjustment is needed for the ceftriaxone + doxycycline first-line regimen, even in advanced CKD — a frequently tested point.

Special Populations — Pregnancy, Pediatrics, and Adolescents

— All pregnant women: GC/CT NAAT at first prenatal visit if <25 or with risk factors

— Retest in third trimester (~28 wks) if high-risk or initial positive

— GC: ceftriaxone 500 mg IM × 1 (safe — Category B equivalent)

— CT: azithromycin 1 g PO × 1 is first-line (doxycycline contraindicated — fetal tooth/bone effects after 2nd trimester; amoxicillin 500 mg TID × 7 days is alternative)

— Test of cure NAAT at 4 weeks post-treatment for both organisms in pregnancy (only setting where TOC is routine)

— Retest in 3rd trimester

— Ophthalmia neonatorum: GC at days 2–5 (hyperacute, risk of corneal perforation); CT at days 5–14 (subacute, mucopurulent)

— Routine erythromycin 0.5% ophthalmic ointment at birth prevents GC but not CT — CT prevented only by maternal screening/treatment

— Neonatal CT pneumonia: 1–3 months old, staccato cough, eosinophilia, hyperinflation on CXR

— Treatment of neonatal GC: ceftriaxone 25–50 mg/kg IV/IM × 1 (avoid in hyperbilirubinemia → use cefotaxime); CT: oral erythromycin × 14 days (monitor for pyloric stenosis)

— GC or CT in a prepubertal child = sexual abuse until proven otherwise → mandated reporting to child protective services; use culture (not NAAT) for forensic standard at extragenital sites in some jurisdictions, though NAAT is increasingly accepted

— Perinatal vertical transmission can persist as conjunctival/vaginal CT up to ~3 years — context-dependent interpretation

— All 50 US states allow minors to consent to STI testing and treatment without parental consent — confidentiality is critical

— EOB explanation-of-benefits leakage to parental insurance is a known confidentiality breach — use Title X clinics or confidential billing options

— HPV vaccination, contraception, and HIV PrEP counseling are natural adjacent topics

Pregnancy screening (CDC/USPSTF)

Pregnancy treatment

Neonatal complications

Pediatric considerations

Adolescents (minors)

Board pearl: Doxycycline → NO in pregnancy; azithromycin 1 g is the CT regimen. Ceftriaxone is fine for GC.

Step 3 management: Confirmed GC in a 6-year-old girl → notify child protective services, obtain forensic specimens, complete STI panel (HIV, syphilis, HBV), arrange child advocacy center evaluation.

Complications and Adverse Outcomes

— Affects ~10–15% of untreated lower-tract infections

— Long-term sequelae: tubal-factor infertility (~10% after one episode, ~50% after three), ectopic pregnancy (6–10× risk), chronic pelvic pain (~30%)

— Tubo-ovarian abscess: requires IV antibiotics ± drainage; rupture is a surgical emergency

— Perihepatic inflammation from ascending GC/CT; RUQ pain, normal LFTs (or mildly elevated); "violin-string" adhesions on laparoscopy

— Epididymo-orchitis, urethral stricture (rare with modern treatment), infertility

— Reactive arthritis (post-CT): "can't see, can't pee, can't climb a tree" — conjunctivitis, urethritis, oligoarthritis; HLA-B27+

— Arthritis-dermatitis syndrome or purulent monoarthritis

— Rare: endocarditis, meningitis, osteomyelitis

— Ophthalmia neonatorum → corneal scarring, blindness if untreated

— CT pneumonitis in 1–3 month-olds

— GC/CT infection increases HIV acquisition and transmission ~2–5× through mucosal inflammation

— Successful STI treatment is HIV prevention

— GC: preterm labor, premature rupture of membranes, chorioamnionitis, postpartum endometritis

— CT: preterm birth, low birth weight, neonatal conjunctivitis/pneumonia

— Genital/anorectal strictures, lymphatic obstruction (genital elephantiasis), fistulas

— Ceftriaxone IM: injection-site pain, rare anaphylaxis, biliary sludging with prolonged use

— Doxycycline: pill esophagitis, photosensitivity, GI upset, candidiasis

— Azithromycin 2 g: GI intolerance prominent

Pelvic inflammatory disease (PID) — feared CT/GC complication

Fitz-Hugh–Curtis syndrome

Male reproductive complications

Disseminated gonococcal infection

Neonatal

HIV transmission

Pregnancy-related

LGV-specific

Adverse drug effects to anticipate and counsel about

Board pearl: RUQ pain + pelvic pain + cervical motion tenderness in a young woman = Fitz-Hugh–Curtis — treat as PID, image to exclude TOA/cholecystitis, no need for laparoscopy unless diagnostic uncertainty.

Step 3 management: Counsel every PID patient that future fertility may be affected and that prompt partner treatment + condom use reduces recurrence — this is a documented counseling expectation.

When to Escalate Care — Admission, Consults, ICU

— Pregnancy with PID

— Severe illness: high fever, nausea/vomiting precluding PO intake, peritoneal signs

— Tubo-ovarian abscess

— Failure to respond to oral therapy within 48–72 h

— Inability to follow up reliably

— Surgical emergency cannot be excluded (appendicitis, ectopic)

— TOA: percutaneous or transvaginal drainage if >7 cm, ruptured, or not responding to IV antibiotics in 48–72 h

— Ruptured TOA with peritonitis → emergent gynecologic surgery

— Suspected ceftriaxone-resistant GC or treatment failure on first-line therapy

— DGI with endocarditis, meningitis, or osteomyelitis

— Complex HIV co-infection with multidrug-resistant organisms

— Adult or neonatal gonococcal conjunctivitis (risk of corneal perforation within 24 h)

— Initial IV ceftriaxone, blood cultures, joint drainage if septic arthritis; transition to oral after clinical improvement and susceptibility confirmation, complete ≥7 days

— Septic shock from ruptured TOA, gonococcal endocarditis, meningitis

— Hemodynamic instability requiring vasopressors or surgical source control

— GC and CT are reportable in all US states — submit to local health department (often automated through the lab)

— Health departments assist with partner notification ("disease intervention specialists")

Outpatient management is appropriate for the vast majority — but escalate for:

Admission for IV antibiotics — PID criteria

Surgical/IR consultation

Infectious disease consult

Ophthalmology consult — urgent same-day

Hospitalization for DGI

ICU indications

Public health notification

CCS pearl: For severe PID with TOA on the simulator: admit, NPO, IV fluids, IV ceftriaxone + doxycycline + metronidazole, OB-GYN consult for possible drainage, serial abdominal exams, daily CBC, repeat pelvic US at 48–72 h.

Board pearl: A young woman with pelvic pain and adnexal mass — always obtain hCG before assuming PID. Ruptured ectopic kills.

Key Differentials — Other STI and Genitourinary Causes

— Persistent or recurrent urethritis/cervicitis after CT/GC negative or treated

— Diagnosis: NAAT (FDA-cleared); send macrolide-resistance assay

— Treatment: doxycycline 100 mg BID × 7 days (debulks load) then moxifloxacin 400 mg daily × 7 days if macrolide-resistant; azithromycin 1 g then 500 mg × 3 days if susceptible

— Frothy yellow-green discharge, vulvar irritation, "strawberry cervix" (punctate hemorrhages — classic)

— Diagnosis: NAAT (preferred), wet mount (low sens)

— Treatment: metronidazole 500 mg BID × 7 days for women; 2 g single dose for men; treat partners; retest at 3 months

— Thin gray discharge, fishy odor, no inflammation; not an STI but linked to STI acquisition

— Amsel criteria, clue cells; treat with metronidazole or clindamycin

— Painful grouped vesicles/ulcers, tender lymphadenopathy, systemic symptoms in primary

— NAAT/PCR of lesion is the gold standard

— Painless chancre (primary), maculopapular rash including palms/soles (secondary)

— RPR + treponemal confirmation; treat with benzathine penicillin G IM

— Painful purulent ulcer, tender suppurative inguinal lymphadenopathy ("buboes")

— GC arthritis: usually monoarticular, purulent, organism may grow from joint fluid

— Reactive arthritis (post-CT): sterile, asymmetric oligoarthritis, HLA-B27, weeks after infection

Mycoplasma genitalium

Trichomonas vaginalis

Bacterial vaginosis

Genital herpes (HSV-2 > HSV-1)

Syphilis

Chancroid (Haemophilus ducreyi) — rare in US

LGV (CT L-serovars) — see chunk 5

Reactive arthritis (post-CT) — differentiates from gonococcal arthritis by sterile joint fluid, HLA-B27, asymmetric oligoarthritis, conjunctivitis/uveitis

Key distinction:

Board pearl: Persistent urethritis after first-line treatment with negative GC/CT → think Mycoplasma genitalium before declaring resistance.

Key Differentials — Non-STI Mimics

— Bacterial UTI: dysuria, frequency, positive urine culture (≥10⁵ CFU/mL of single uropathogen), often pyuria + bacteriuria

— CT/GC urethritis: dysuria, sterile pyuria, negative routine culture → reflex to NAAT

— Migratory periumbilical → RLQ pain, anorexia, fever; localized peritoneal signs

— CT scan with IV contrast if uncertain; pelvic ultrasound to evaluate adnexa

— Sudden severe unilateral pelvic pain, nausea/vomiting; Doppler ultrasound assesses ovarian perfusion

— Amenorrhea, pelvic pain ± bleeding, positive hCG, no IUP on ultrasound — always check hCG in reproductive-age women with pelvic pain

— Chronic cyclic pelvic pain, dyspareunia, dysmenorrhea, infertility; not infectious

— Acute severe scrotal pain in adolescent/young adult, absent cremasteric reflex, negative Prehn sign, high-riding testis

— Doppler ultrasound urgently; surgical emergency (6-h window)

— Reducible/incarcerated groin mass; not infectious

— Rare; consider chemical/physical irritants

— Cervical cap/diaphragm trauma, douching, allergic reaction

— Recurrent oral and genital ulcers, uveitis, pathergy; non-infectious systemic vasculitis

— Synovial fluid analysis: WBC >50,000 with neutrophil predominance + positive Gram stain/culture = septic; <10,000 with negative culture suggests reactive

— TOA vs ovarian malignancy vs endometrioma — imaging characteristics, CA-125, age-appropriate workup

Urinary tract infection

Appendicitis (vs PID)

Ovarian torsion / ruptured ovarian cyst

Ectopic pregnancy

Endometriosis

Testicular torsion

Inguinal hernia

Drug-induced urethritis

Non-infectious cervicitis

Behçet disease

Reactive vs septic arthritis

Pelvic mass workup

Board pearl: A sexually active 17-year-old boy with scrotal pain — rule out torsion with Doppler before assuming epididymitis. Missing torsion costs a testicle.

Step 3 management: Dysuria + sterile pyuria + negative urine culture in a sexually active patient → next step is GC/CT NAAT, not repeat urine culture.

Secondary Prevention, Counseling, and Long-Term Plan

— Identify all sexual partners within prior 60 days (or most recent partner if last contact >60 days)

— Three approaches:

— Patient referral: patient informs partners directly (most common)

— Provider referral: clinician/health department contacts partners while preserving index patient confidentiality

— Expedited Partner Therapy (EPT): prescribe medications for partner without prior exam — legal in most US states (check status)

— EPT regimen: cefixime 800 mg PO + doxycycline 100 mg BID × 7 days (oral cefixime because no IM available outside clinic)

— Retest all treated patients at 3 months for reinfection — single most impactful action to reduce sequelae

— If patient not seen at 3 months, retest within 12 months at next clinical encounter

— Condom use with every act; correct technique

— Reduce number of partners, mutual monogamy, abstinence

— Vaccination: hepatitis B, HPV (through age 26, shared decision through 45), mpox in MSM at risk

— Substance use that impairs safer-sex decision-making

— Offer to MSM, transgender persons, serodiscordant couples, IDU, others at risk — daily oral TDF/FTC or TAF/FTC; injectable cabotegravir alternative

— Bacterial STIs are a marker of PrEP indication

— As above (chunk 8): consider in MSM/transgender women with bacterial STI in last 12 months

— HPV vaccine: through age 26 routine, 27–45 shared decision-making

— HBV: complete series if not immune

— No vaccine yet for GC or CT (4CMenB vaccine shows partial cross-protection for GC, under study)

— Counseling provided, partners notified, EPT given, retest plan

Partner notification — mandatory step

Retesting (not test of cure)

Behavioral counseling

Pre-exposure prophylaxis (PrEP) for HIV

Doxy-PEP

Vaccination

Documentation

Board pearl: 3-month retest > test of cure in nearly all uncomplicated cases — reinfection is far more common than treatment failure.

Step 3 management: At the index treatment visit, document EPT prescription, abstinence counseling for 7 days, and a 3-month retest appointment.

Follow-Up, Monitoring, and Counseling Cadence

— Day 0: diagnosis, treatment, counseling, partner notification, EPT, abstinence × 7 days

— 7–14 days: phone check-in or return visit if symptoms persist; TOC NAAT only for pharyngeal GC, pregnancy, alternative regimens, or persistent symptoms

— 3 months: NAAT retest for reinfection (urogenital + all exposed sites)

— 12 months: ongoing screening based on risk (annual minimum for at-risk groups)

— Reassess within 48–72 h to confirm clinical improvement (defervescence, decreased pain, decreased tenderness)

— No improvement → escalate to IV therapy, reimage for TOA, broaden differential

— Complete 14-day course; counsel on fertility implications, contraception, condom use

— Minimum 7 days IV/IM ceftriaxone; longer for endocarditis (4 wks) or meningitis (10–14 days)

— ID consultation; document complete resolution of joint and skin findings

— TOC NAAT at 4 weeks post-treatment for both GC and CT

— Repeat screening in 3rd trimester regardless of initial result if risk persists

— Confirm partners treated and asymptomatic before resuming intercourse

— Reinforce 7-day abstinence (or until 7 days after single-dose therapy)

— Discuss HIV PrEP eligibility; offer HIV testing if not done

— Behavioral risk reduction tailored to patient context

— HEDIS measure: chlamydia screening in women 16–24 — track at the panel level

— CDC patient handouts, sexual health navigation, link to local Title X clinic for confidential follow-up

— Empiric prophylaxis at presentation: ceftriaxone 500 mg IM + doxycycline 100 mg BID × 7 days + metronidazole 2 g PO (× 1) or 500 mg BID × 7 days; HIV PEP; emergency contraception; HBV vaccination if non-immune

— Follow-up testing at 2 weeks (NAAT), 6 weeks (HIV, syphilis), 3 and 6 months (HIV/syphilis serology)

Standard follow-up timeline (uncomplicated urogenital GC/CT)

PID follow-up

DGI follow-up

Pregnancy

Counseling content (every visit)

Documentation for value-based care/quality metrics

Self-management resources

Special: Sexual assault survivors

Board pearl: TOC is not routine — retest at 3 months is. This trips up examinees.

Step 3 management: A pregnant patient treated for CT at 14 weeks — order TOC NAAT at 18 weeks and repeat screening at 28 weeks.

Ethical, Legal, and Patient Safety Considerations

— GC and CT are nationally notifiable — reportable to state/local health departments in all 50 states (typically by the laboratory automatically, but clinicians remain responsible)

— Failure to report can result in licensure action in some states

— All states permit minors to consent to STI diagnosis and treatment without parental consent

— EOB (explanation of benefits) leakage to parent's insurance is a real-world confidentiality breach — counsel adolescents on Title X funded clinics (sliding-scale, confidential) or other confidential billing pathways

— Documentation must protect confidentiality (e.g., use sealed/confidential portions of EMR per institutional policy)

— Balance index patient confidentiality with public health duty to warn

— Provider/health department referral allows partner notification without disclosing the index patient's identity

— Expedited Partner Therapy is legal in most states but check state-specific status (variable for MSM partners in some jurisdictions)

— GC or CT in a prepubertal child = sexual abuse until proven otherwise → mandatory CPS report and child-advocacy-center evaluation

— Adult sexual assault: mandatory reporting varies by state for competent adults; offer reporting resources but generally do not report without consent

— Intimate partner violence: screen all patients diagnosed with STIs for IPV

— STI testing requires consent, but in most US settings opt-out screening (HIV, GC/CT in pregnancy) is standard practice

— Capacity to refuse testing or treatment must be respected

— High-risk failure points: results returned after the patient leaves and no callback; partner not notified; EPT not actually dispensed; 3-month retest not scheduled

— Closed-loop result management is a patient-safety priority — use EMR reminders, patient portals, registry callbacks

— Empiric over-treatment without indication contributes to resistance; conversely, missed treatment in symptomatic patients propagates spread — both are safety issues

— Many states have HIV disclosure laws — distinct from GC/CT; counsel separately

Mandatory reporting

Adolescent confidentiality

Partner notification ethics

Suspected abuse

Capacity and informed consent

Transition-of-care safety

Antimicrobial stewardship

HIV disclosure

Board pearl: A 15-year-old requests STI testing and asks the result not be shared with parents — honor the request, document, and counsel on confidential billing.

Step 3 management: Document GC/CT report to public health, partner notification plan, EPT dispensation, and 3-month retest order at the index visit — these are all auditable quality measures.

High-Yield Associations and Rapid-Fire Facts

— A–C: trachoma (chronic conjunctivitis → blindness, leading infectious cause of blindness worldwide)

— D–K: urogenital infection, neonatal conjunctivitis/pneumonia

— L1–L3: lymphogranuloma venereum

GC = gram-negative diplococci, intracellular within PMNs on Gram stain of urethral discharge

CT = obligate intracellular bacterium with elementary/reticulate body life cycle

Serovars matter

DGI → terminal complement deficiency (C5–C9) screen if recurrent; check CH50

Fitz-Hugh–Curtis = perihepatitis from GC/CT ascending; "violin-string" adhesions

Reactive arthritis (post-CT) = HLA-B27, "can't see/pee/climb a tree"

Ophthalmia neonatorum timing: GC days 2–5, CT days 5–14

CT pneumonia in 1–3 month-old: staccato cough, afebrile, eosinophilia, hyperinflation

First-line GC = ceftriaxone 500 mg IM (1 g if ≥150 kg)

First-line CT = doxycycline 100 mg BID × 7 days (azithromycin in pregnancy)

LGV = doxycycline × 21 days

PID outpatient = ceftriaxone + doxycycline × 14 days + metronidazole

Test of cure = pharyngeal GC, pregnancy, alternative regimen, persistent symptoms — at 4 weeks for pregnancy, 7–14 days otherwise

Retest for reinfection at 3 months universally

Partners: 60-day lookback; EPT legal in most US states

HEDIS quality measure: annual CT screening in sexually active women 16–24

MSM 3-site testing: urethral, rectal, pharyngeal — urine alone misses majority of extragenital infections

Doxy-PEP: 200 mg within 72 h after condomless sex, MSM/TGW with prior bacterial STI

No vaccine currently licensed for GC or CT (4CMenB cross-protection for GC under study)

Pyuria with negative urine culture in young patient = suspect CT/GC urethritis

Strawberry cervix = trichomonas (not GC/CT)

Painless inguinal "groove sign" = LGV

Empiric treatment of suspected PID prevents infertility — do not wait for NAAT results

Co-infection: ~20–40% of GC patients have concurrent CT

Fluoroquinolones are no longer first-line for GC — resistance prevalent

Board pearl: If the question asks "best initial therapy for confirmed urogenital gonorrhea" — answer ceftriaxone 500 mg IM + doxycycline 100 mg BID × 7 days, unless CT clearly excluded.

Board Question Stem Patterns

— 22-year-old sexually active woman at routine visit, no symptoms → next best step = GC/CT NAAT (vaginal swab); choose this over Pap or "no testing needed"

— Young sexually active patient with dysuria, urinalysis showing pyuria, urine culture negative → answer: GC/CT NAAT

— Young woman with bilateral adnexal tenderness and CMT, fever 38.5°C, sexually active → start ceftriaxone + doxycycline + metronidazole without waiting for NAAT; do hCG first

— Patient confirmed positive for CT; asks about boyfriend who lives in another state → answer: expedited partner therapy with doxycycline (if legal in that state) and counsel notification

— Patient returns 5 weeks after treatment with recurrent urethral discharge → most likely reinfection; retest, retreat, address partner

— Pregnant patient with positive CT NAAT at 14 weeks → azithromycin 1 g PO × 1, NOT doxycycline; TOC at 4 weeks

— Young sexually active patient with migratory polyarthralgia, tenosynovitis of wrist, pustular skin lesions → DGI; obtain blood + joint + mucosal cultures; start IV ceftriaxone; screen for complement deficiency if recurrent

— Newborn at day 3 with copious purulent eye discharge → GC conjunctivitis; ceftriaxone 25–50 mg/kg IV/IM × 1, ophthalmology consult, evaluate mother and partners

— 16-year-old requests STI test, asks parents not be informed → honor confidentiality, refer to Title X clinic for billing privacy

— 5-year-old girl with positive vaginal GC culture → mandated CPS report, child advocacy center evaluation

— Male with persistent urethral symptoms after completing doxycycline, retest GC/CT negative → test for Mycoplasma genitalium

— Woman with PID and 8-cm adnexal mass on ultrasound → admit for IV antibiotics, GYN consult for possible drainage

Pattern 1 — Asymptomatic screening

Pattern 2 — Sterile pyuria

Pattern 3 — Empiric PID

Pattern 4 — Partner management

Pattern 5 — Treatment failure vs reinfection

Pattern 6 — Pregnancy

Pattern 7 — DGI

Pattern 8 — Ophthalmia neonatorum

Pattern 9 — Adolescent confidentiality

Pattern 10 — Prepubertal child

Pattern 11 — Persistent urethritis

Pattern 12 — TOA

Board pearl: When the answer requires "next best step" and the patient has any STI risk factor with GU symptoms, NAAT for GC/CT is nearly always correct over urine culture or Pap.

One-Line Recap

For all sexually active patients with risk factors or symptoms, test for GC and CT by NAAT at all exposed sites, treat uncomplicated infection with ceftriaxone 500 mg IM (GC) + doxycycline 100 mg BID × 7 days (CT) — substituting azithromycin 1 g in pregnancy — notify and treat partners from the prior 60 days (EPT where legal), counsel 7-day abstinence, and retest at 3 months for reinfection.

Screening: women <25 annually; pregnant women at first prenatal visit + 3rd trimester if high-risk; MSM at all exposed sites every 3–12 months; persons with HIV at entry and annually

Diagnostics: NAAT is the test of choice — vaginal swab in women, first-catch urine in men, 3-site testing in MSM; sterile pyuria + dysuria in a sexually active patient = NAAT

Treatment: ceftriaxone 500 mg IM × 1 (GC) + doxycycline 100 mg BID × 7 days (CT); PID adds metronidazole × 14 days; LGV gets doxycycline × 21 days; DGI needs IV ceftriaxone ≥7 days

Follow-up: TOC only for pharyngeal GC, pregnancy, alternative regimens, or persistent symptoms; universal retest at 3 months for reinfection

Partner management: 60-day lookback; EPT legal in most states; report to public health (mandatory); honor adolescent confidentiality

Complications to prevent: infertility, ectopic pregnancy, chronic pelvic pain (CT/GC); ophthalmia neonatorum; DGI; HIV acquisition

Step 3 management: The exam rewards bundled action — test at all exposed sites, treat empirically when probability is high, treat partners through EPT, and schedule the 3-month retest at the index visit.