Servisitis

01Pathophysiology

The cervix is lined by two types of epithelium. The ectocervix is covered by stratified squamous epithelium, while the endocervical canal is lined by columnar epithelium. The junction between these two cell types is called the squamocolumnar junction (transformation zone), and this is the primary target of infection in cervicitis.

Chlamydia trachomatis is an obligate intracellular organism. It preferentially infects the columnar epithelial cells of the endocervix because it requires host cell machinery to replicate. Once inside, it hijacks cellular metabolism to form intracytoplasmic inclusions called reticulate bodies. The host immune response to this intracellular invasion triggers a robust neutrophilic infiltration of the endocervical mucosa, which produces the characteristic mucopurulent discharge.

Neisseria gonorrhoeae, a gram-negative intracellular diplococcus, also targets the columnar epithelium. It adheres via pili and Opa proteins to mucosal surfaces, penetrates between and through epithelial cells, and provokes an intense acute inflammatory response. This is why gonococcal infections tend to produce a more overtly purulent discharge compared to the often subtle or absent discharge of chlamydial infection.

The inflammatory process weakens the structural integrity of the epithelium, making the cervix friable. This explains why gentle swab contact induces bleeding, and why patients report intermenstrual or postcoital spotting. The inflammation also disrupts the normal cervical mucus barrier, which has two critical consequences: it creates a pathway for ascending infection to the upper genital tract (leading to PID), and in pregnancy, it increases the risk of preterm labor and neonatal transmission.

A concept frequently tested is the distinction between cervicitis (infection of the endocervix) and vaginitis (infection of the vaginal epithelium). The vaginal squamous epithelium is relatively resistant to chlamydia and gonorrhea, which is why these organisms cause cervicitis rather than vaginitis. In contrast, Trichomonas vaginalis and Candida primarily infect the vaginal mucosa, producing vaginitis. Understanding this tissue tropism is essential for distinguishing these conditions on exam questions.

02Classification and Clinical Manifestation

By Causative Organism

By Clinical Course

03Diagnostic Workup

The best initial step when a sexually active woman presents with abnormal vaginal discharge or postcoital bleeding is a speculum examination. On exam, you are looking for two findings that define cervicitis clinically: (1) mucopurulent or purulent endocervical discharge visible at the cervical os or on an endocervical swab, and (2) easily induced endocervical bleeding when a cotton swab is gently passed through the os. The presence of either finding is sufficient to make a clinical diagnosis and initiate empiric treatment.

The most accurate (confirmatory) test is a NAAT (nucleic acid amplification test) for C. trachomatis and N. gonorrhoeae. NAAT has the highest sensitivity and specificity of any diagnostic modality for these organisms. It can be performed on an endocervical swab, a self-collected vaginal swab, or a first-void urine specimen. This test identifies the causative organism but takes time to result, which is why you treat empirically based on clinical findings before results return.

The endocervical Gram stain is a supportive tool. A finding of $\ge 10\backslash geq\; 10$ polymorphonuclear leukocytes (PMNs) per oil immersion field on endocervical secretions supports the diagnosis of cervicitis. If you also see gram-negative intracellular diplococci, you can make a presumptive diagnosis of gonococcal cervicitis on the spot. However, Gram stain has poor sensitivity for gonorrhea in women (about 50%) and cannot detect chlamydia at all, so it does not replace NAAT.

A wet mount should be performed when the history or discharge character suggests trichomoniasis (frothy, malodorous, yellow-green discharge) or bacterial vaginosis. Finding motile trichomonads on wet mount is diagnostic, though sensitivity is limited (about 60%). NAAT for Trichomonas is more sensitive and should be ordered if wet mount is negative but clinical suspicion remains.

All patients with a diagnosed STI should also be screened for HIV and syphilis, as co-infection is common and alters management. A pregnancy test is essential before prescribing doxycycline, which is teratogenic.

04Management and Treatment

Acute Stabilization and Empiric Therapy

When clinical examination reveals mucopurulent cervicitis, the next best step is empiric antibiotic therapy. Do not wait for NAAT results. The rationale is straightforward: delaying treatment increases the risk of ascending infection (PID), ongoing transmission to sexual partners, and complications in pregnancy.

The standard empiric regimen treats both C. trachomatis and N. gonorrhoeae simultaneously, because coinfection rates are high and clinical features alone cannot reliably distinguish between the two. The current recommended regimen is Ceftriaxone 500 mg given as a single intramuscular injection to cover gonorrhea, plus Doxycycline 100 mg taken orally twice daily for 7 days to cover chlamydia.

An important update to recognize: Doxycycline has replaced azithromycin as the preferred first-line agent for chlamydia in non-pregnant patients. This change was driven by rising macrolide resistance in both N. gonorrhoeae and M. genitalium, and by evidence that doxycycline has superior cure rates for chlamydial infections compared to single-dose azithromycin. This is a high-yield fact for exams that test current guideline knowledge.

Pregnancy Considerations

In pregnant women, doxycycline is absolutely contraindicated due to teratogenic effects (tooth discoloration, impaired bone growth in the fetus). The substitute for chlamydia coverage is Azithromycin 1 g PO as a single dose. Ceftriaxone remains safe and is used at the same dose for gonorrhea. A test of cure (repeat NAAT at 4 weeks after treatment) is recommended in pregnancy to confirm eradication.

Partner Management

Sexual partners within the preceding 60 days should be evaluated and treated empirically, even if asymptomatic. If the patient's last sexual contact was more than 60 days ago, the most recent partner should still be treated. Expedited partner therapy (providing prescriptions for the partner without an in-person evaluation) is an acceptable strategy in many jurisdictions when partners are unlikely to seek care on their own. Patients should abstain from intercourse for 7 days after both they and their partner(s) have completed treatment.

Follow-Up

Routine test of cure is not required for non-pregnant patients treated with first-line regimens. However, rescreening with NAAT at 3 months after treatment is recommended for all patients because reinfection rates are high. If symptoms persist after completing treatment, consider M. genitalium as a cause of persistent cervicitis.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common mistake students make with cervicitis questions is confusing it with vaginitis or missing the diagnosis entirely because the patient is asymptomatic. Exam vignettes love to present a young, sexually active woman who comes in for a routine visit or a Pap smear, and the examiner mentions mucopurulent discharge or cervical friability almost as a side detail buried in the physical exam findings. If you skim past the speculum exam description and focus only on the chief complaint, you will miss the diagnosis. The core competency being tested is whether you can identify cervicitis based on objective exam findings rather than relying on symptoms alone.

A second common trap involves confusing cervical ectropion with cervicitis. Vignettes may describe a young woman on oral contraceptives with a "reddened" or "erythematous" cervix that bleeds slightly on contact. Students reflexively jump to cervicitis and start empiric antibiotics. The critical discriminator is the absence of mucopurulent discharge. Ectropion is a normal anatomic variant where columnar epithelium is visible on the ectocervix. It requires no treatment.

A third tested concept is guideline-current antibiotic selection. Older resources still list azithromycin 1 g as the first-line agent for chlamydia. Per updated guidelines, doxycycline is now preferred except in pregnancy. Selecting azithromycin as first-line in a non-pregnant patient may appear as a distractor answer. Similarly, remember that ceftriaxone alone only covers gonorrhea, so always pair it with a second agent for chlamydia coverage.

Finally, always remember the escalation pathway. Cervicitis left untreated ascends to become PID. If the vignette adds cervical motion tenderness, fever, or adnexal tenderness to the picture, the diagnosis has shifted to PID, and the management changes significantly (typically requiring broader-spectrum antibiotics and possibly hospitalization). The exam tests whether you can recognize when the disease has crossed that threshold.