A 52-year-old woman presents to the ophthalmology clinic with a 3-week history of persistent epiphora and purulent discharge from the left eye. On examination, there is marked swelling and tenderness over the medial canthus, with a palpable mass. Fluorescein dye disappears from the conjunctival sac within 2 minutes bilaterally. Gentle pressure over the lacrimal sac produces purulent material from the punctum. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Acute Dacryocystitis with Abscess **Key Point:** The combination of epiphora, purulent discharge, medial canthal swelling, palpable mass, and regurgitation of pus on pressure over the lacrimal sac is pathognomonic for acute dacryocystitis, often with abscess formation. ### Pathophysiology Dacryocystitis results from obstruction of the nasolacrimal duct (commonly at the plica lacrimalis or valve of Hasner) with secondary bacterial infection. The lacrimal sac becomes distended with infected fluid, leading to: 1. Inflammatory edema and swelling of the medial canthal tissues 2. Accumulation of purulent material within the sac 3. Possible rupture and abscess formation 4. Regurgitation of pus on sac pressure (pathognomonic sign) ### Diagnostic Features | Feature | Finding in This Case | Significance | |---------|----------------------|---------------| | **Epiphora** | Present for 3 weeks | Indicates nasolacrimal duct obstruction | | **Purulent discharge** | Present | Confirms bacterial infection | | **Medial canthal swelling** | Marked, with palpable mass | Suggests abscess formation | | **Sac pressure test** | Pus regurgitates from punctum | Pathognomonic for dacryocystitis | | **Dye disappearance test** | Normal (< 5 min) | Rules out functional obstruction; confirms anatomic block | **Clinical Pearl:** The dye disappearance test is normal in this patient because the dye can still drain via the nasolacrimal duct (the obstruction is distal, at the valve of Hasner). However, the sac itself is infected and distended, causing external swelling and pus regurgitation. **High-Yield:** Acute dacryocystitis is a medical emergency if accompanied by cellulitis or abscess, as it can lead to orbital cellulitis, meningitis, or cavernous sinus thrombosis if untreated. ### Management Approach ```mermaid flowchart TD A[Acute Dacryocystitis]:::outcome --> B{Systemic signs?}:::decision B -->|Fever, cellulitis, proptosis| C[Hospitalize, IV antibiotics]:::action B -->|Localized infection| D[Oral antibiotics + warm compresses]:::action C --> E[Broad-spectrum coverage<br/>e.g., Amoxicillin-clavulanate]:::action D --> E E --> F{Response in 48-72 hrs?}:::decision F -->|Yes| G[Continue medical management]:::action F -->|No| H[Probe and irrigate<br/>or DCR if chronic]:::action H --> I[Definitive relief]:::outcome ``` **Warning:** Do NOT confuse acute dacryocystitis with canaliculitis (which presents with punctal discharge but no medial canthal mass) or with simple nasolacrimal duct obstruction (which causes epiphora but no infection or swelling).