A 52-year-old man with a 6-month history of bilateral chronic conjunctivitis presents with mild ocular irritation, minimal discharge, and recurrent episodes of follicular reaction. He reports no photophobia or pain. Examination reveals mild papillary hypertrophy of the upper tarsal conjunctiva and fine linear scarring. He denies recent travel or contact with sick individuals. What is the most likely diagnosis?

Explanation

## Diagnosis: Chronic Trachoma (Active Stage) **Key Point:** Chronic trachoma presents with mild symptoms, follicular conjunctivitis, and progressive linear scarring of the upper tarsal conjunctiva — the pathognomonic triad in endemic areas. ### Clinical Features of Chronic Trachoma | Feature | Chronic Trachoma | Acute Trachoma | |---------|------------------|----------------| | **Duration** | Months to years | 1–3 weeks | | **Discharge** | Minimal, mucoid | Purulent | | **Pain/Photophobia** | Absent or mild | Marked | | **Tarsal conjunctiva** | Papillae + follicles + scarring | Follicles prominent | | **Scarring pattern** | Linear (Arlt's line) | None | | **Symptoms** | Mild irritation, recurrent flares | Acute inflammation | **High-Yield:** Arlt's line — horizontal linear scarring of the upper tarsal conjunctiva — is pathognomonic for previous trachoma and indicates chronicity. ### Pathophysiology Chlamydia trachomatis (serovars A, B, Ba, C) causes chronic inflammation with: 1. Repeated infection cycles 2. Progressive fibrosis and scarring 3. Trichiasis and entropion (late complications) 4. Corneal opacification and blindness (if untreated) **Mnemonic: TRACHOMA = Trichiasis, Recurrent infection, Arlt's line, Chronic follicles, Horizontal scarring, Ocular blindness, Minimal discharge, Atypical presentation (mild)** ### Diagnostic Confirmation - Giemsa stain: intracytoplasmic inclusions in epithelial cells - PCR/NAAT for Chlamydia trachomatis - Conjunctival biopsy (rarely needed): Leber's follicles and Busacca bodies ### Treatment **Systemic:** Azithromycin 20 mg/kg/day × 3 days (single-dose regimen) or doxycycline 100 mg BD × 3 weeks. **Topical:** Tetracycline ointment 1% TDS × 6 weeks (adjunctive). **Surgical:** Trichiasis correction, entropion repair (if scarring severe). **Clinical Pearl:** Trachoma is the leading infectious cause of blindness worldwide, endemic in sub-Saharan Africa, Middle East, and parts of South Asia. Public health screening and mass drug administration are key prevention strategies. [cite:Kanski & Bowling Clinical Ophthalmology 8e Ch 4; WHO Trachoma Guidelines]