A 28-year-old woman from Delhi presents with a 3-week history of floaters, blurred vision, and photopsia in the right eye. On examination, she has vitritis with 2+ haze, posterior synechiae, and a granulomatous anterior chamber reaction with mutton-fat keratic precipitates. Fundoscopy reveals multiple focal areas of retinal whitening at the posterior pole with hemorrhages. Chest X-ray shows bilateral hilar lymphadenopathy and erythema nodosum is noted on the skin. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Sarcoidosis ### Key Clinical Features **Key Point:** Sarcoidosis is a multisystem granulomatous disorder that commonly affects the eye, presenting with both anterior and posterior uveitis. The combination of findings in this case is classic for sarcoidosis: | Feature | Finding in This Case | Sarcoidosis Hallmark | |---------|----------------------|---------------------| | **Anterior chamber reaction** | Granulomatous (mutton-fat KP) | Yes — granulomatous inflammation | | **Posterior involvement** | Vitritis + focal retinal infiltrates | Yes — "candle-wax" drippings, snowball opacities | | **Systemic signs** | Hilar lymphadenopathy + erythema nodosum | Yes — Löfgren syndrome variant | | **Demographics** | Young woman | Common in women 20–40 years | ### Pathophysiology **High-Yield:** Sarcoidosis causes non-caseating granulomatous inflammation. The Kveim test (intradermal injection of sarcoid antigen) is diagnostic but rarely used clinically; ACE level and serum calcium are supportive. ### Diagnostic Approach for Sarcoidosis-Associated Uveitis ```mermaid flowchart TD A[Granulomatous uveitis + systemic signs]:::outcome --> B{Chest imaging findings?}:::decision B -->|Hilar lymphadenopathy| C[Consider sarcoidosis]:::action B -->|Cavitary lesion| D[Consider TB]:::action C --> E[Check ACE level, serum Ca2+]:::action E --> F[Kveim test if needed]:::action F --> G[Diagnosis: Sarcoidosis]:::outcome ``` ### Why Sarcoidosis Over TB? While TB can present with granulomatous uveitis and hilar lymphadenopathy, **sarcoidosis is more likely here because:** - Erythema nodosum is a strong pointer to sarcoidosis (Löfgren syndrome) - TB typically causes caseating granulomas (not seen on routine histology in this vignette) - TB uveitis is often unilateral and more indolent; sarcoidosis can present acutely - The mutton-fat KP and posterior "candle-wax" infiltrates are classic for sarcoidosis **Clinical Pearl:** Löfgren syndrome = acute sarcoidosis with the triad of erythema nodosum, hilar lymphadenopathy, and acute uveitis. It has the best prognosis among sarcoidosis presentations. ### Management 1. Topical corticosteroids for anterior uveitis 2. Systemic corticosteroids for posterior involvement and systemic disease 3. Immunosuppressants (methotrexate, azathioprine) for steroid-dependent cases [cite:Kanski's Clinical Ophthalmology 9e Ch 10]