A 28-year-old woman presents with a painful, red swelling on the upper eyelid margin that has been present for 3 days. She reports tenderness, mild fever (37.8°C), and difficulty opening her eye. On examination, there is localized erythema and edema at the lid margin with a small pustule visible. The conjunctiva is clear and vision is normal. What is the most likely diagnosis?

Explanation

## Clinical Presentation and Diagnosis **Key Point:** An external hordeolum (stye) is an acute, purulent infection of the glands of Moll or Zeis at the eyelid margin, presenting with rapid onset of pain, erythema, and a pustule. ### Distinguishing Features of External Hordeolum | Feature | External Hordeolum | Internal Hordeolum | Chalazion | | --- | --- | --- | --- | | **Onset** | Acute (2–5 days) | Acute (2–5 days) | Insidious (weeks) | | **Location** | Lid margin with pustule | Behind lid margin (conjunctival surface) | Lid margin or deeper | | **Pain** | Severe, localized | Moderate to severe | Minimal or absent | | **Fever** | May occur | May occur | Absent | | **Pustule** | Visible at margin | Not visible externally | Absent | | **Cause** | Infection of Moll/Zeis glands | Infection of meibomian glands | Sterile lipogranulomatous inflammation | **High-Yield:** The presence of a **visible pustule at the eyelid margin** with acute pain and fever is pathognomonic for external hordeolum. Internal hordeolum would show no external pustule but rather conjunctival inflammation. Chalazion is painless and chronic. ### Pathophysiology 1. Infection of the sebaceous glands of Moll or Zeis (located at the lid margin) 2. Staphylococcus aureus is the most common causative organism 3. Acute suppuration leads to pustule formation at the lid margin 4. Self-limited; most resolve spontaneously within 1–2 weeks **Clinical Pearl:** External hordeolum often points and drains spontaneously, providing relief. Internal hordeolum may point toward the conjunctiva and may leave a residual chalazion if not fully resolved. ### Management - Warm compresses (15 minutes, 4–6 times daily) to promote drainage - Topical antibiotics (erythromycin or bacitracin ointment) if secondary infection risk - Systemic antibiotics rarely needed unless cellulitis develops - Incision and drainage if fluctuant and not draining spontaneously - Avoid squeezing or expressing the lesion **Warning:** Do not confuse external hordeolum with chalazion—chalazion is painless, chronic, and sterile, requiring different management (warm compresses, intralesional steroid injection, or surgical excision if persistent).