A 28-year-old woman presents with a 3-day history of bilateral conjunctival injection, copious purulent discharge, and severe eye pain. On examination, she has chemosis, lid edema, and a thick mucopurulent exudate. Gram stain of the discharge shows gram-negative diplococci. She reports unprotected sexual contact 5 days ago. What is the most likely causative organism and the recommended first-line treatment?

Explanation

## Diagnosis: Gonococcal Conjunctivitis **Key Point:** Gram-negative diplococci on Gram stain in a sexually active patient with acute purulent conjunctivitis is pathognomonic for *Neisseria gonorrhoeae*. ### Clinical Features of Gonococcal Conjunctivitis - **Onset:** 2–5 days post-exposure (shorter than chlamydial) - **Presentation:** Severe hyperacute conjunctivitis with copious purulent discharge, chemosis, lid edema - **Gram stain:** Gram-negative intracellular diplococci within polymorphonuclear leukocytes - **Severity:** Can progress to corneal ulceration and perforation if untreated ### Treatment Regimen | Component | Dosing | Rationale | | --- | --- | --- | | Ceftriaxone | 1 g IM single dose | First-line systemic agent; treats urogenital infection simultaneously | | Azithromycin | 1 g orally single dose | Covers possible co-infection with *Chlamydia trachomatis* (25–45% co-infection rate) | | Saline irrigation | Frequent (every 1–2 hours initially) | Mechanical removal of discharge; reduces bacterial load | | Topical antibiotics | Bacitracin or erythromycin ointment | Adjunctive; does NOT replace systemic therapy | **Clinical Pearl:** Gonococcal conjunctivitis is a medical emergency because of the high risk of corneal involvement and blindness. Systemic antibiotics are mandatory — topical agents alone are insufficient. **High-Yield:** Neonatal gonococcal ophthalmia neonatorum (GON) occurs 2–5 days post-delivery and is preventable by silver nitrate (1%) or erythromycin ointment at birth. **Warning:** Do NOT use tetracyclines in pregnancy or children — they cause tooth discoloration and bone dysplasia. Cephalosporins are safe in pregnancy. ### Differential Diagnosis | Organism | Onset | Discharge | Gram Stain | Treatment | | --- | --- | --- | --- | --- | | *N. gonorrhoeae* | 2–5 days | Copious, purulent | GN diplococci (intracellular) | Ceftriaxone + azithromycin | | *C. trachomatis* | 5–14 days | Mucopurulent | Intracellular inclusions (Giemsa) | Azithromycin or doxycycline | | *S. aureus* | 1–3 days | Purulent | GPC clusters | Fluoroquinolone or cephalosporin | | *P. aeruginosa* | 1–2 days | Purulent, greenish | GN rod | Fluoroquinolone or aminoglycoside | **Mnemonic: GONORRHEA URGENCY** — **G**ram-negative, **O**nset 2–5 days, **N**eisseria, **O**phthalmic emergency, **R**equires systemic therapy, **R**isk of corneal perforation, **H**yperacute presentation, **E**xudative, **A** — Always treat partner.