A 52-year-old woman presents to the ophthalmology clinic with a 3-week history of purulent discharge from the left eye, persistent epiphora, and swelling over the medial canthus. On examination, there is a tender mass below the medial canthus with erythema and warmth. Pressure over the lacrimal sac produces mucopurulent material from the punctum. The patient reports a history of recurrent episodes over the past 6 months. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Acute Dacryocystitis **Key Point:** Acute dacryocystitis presents with the classic triad of epiphora, purulent discharge, and swelling over the medial canthus below the medial canthal tendon. ### Pathophysiology Dacryocystitis results from obstruction of the nasolacrimal duct (most commonly at the plica lacrimalis or valve of Hasner) with secondary bacterial infection. The stagnant tears become infected, typically by Staphylococcus aureus or Streptococcus pneumoniae. ### Clinical Features Supporting the Diagnosis | Feature | Significance | |---------|-------------| | Tender swelling below medial canthus | Characteristic location of lacrimal sac | | Purulent discharge from punctum on pressure | Diagnostic sign (Regenbogen's test positive) | | Epiphora + mucopurulent discharge | Indicates duct obstruction + infection | | Recurrent episodes over 6 months | Suggests chronic obstruction predisposing to recurrent infection | | Erythema and warmth | Active inflammation/infection | **High-Yield:** The **positive Regenbogen test** (pus from punctum on lacrimal sac pressure) is pathognomonic for dacryocystitis and distinguishes it from other lacrimal pathology. ### Management Approach ```mermaid flowchart TD A[Acute Dacryocystitis]:::outcome --> B{Severity?}:::decision B -->|Uncomplicated| C[Warm compresses + Topical antibiotics]:::action B -->|Complicated/Systemic signs| D[Systemic antibiotics IV/oral]:::action C --> E{Response in 48-72 hrs?}:::decision D --> E E -->|Yes| F[Continue medical therapy]:::action E -->|No| G[Incision & drainage if abscess]:::action F --> H[Definitive: Dacryocystorhinostomy]:::action G --> H ``` **Clinical Pearl:** Acute dacryocystitis can progress to orbital cellulitis or cavernous sinus thrombosis if untreated; therefore, systemic antibiotics are often indicated even in mild cases. **Mnemonic: EPIPHORA** — Epiphora, Purulent discharge, Infection (bacterial), Punctal expression positive, Hypertrophic swelling, Obstruction of duct, Recurrent episodes, Antibiotic therapy [cite:Khurana 6e Ch 9]