chalazion

**Definition:** Chronic, sterile, lipogranulomatous inflammation of the eyelid due to a blocked meibomian gland (sebaceous glands in the tarsal plate that secrete the oily layer of the tear film).

**Pathophysiology:** Obstruction of the meibomian gland duct leads to retained sebum. Lipid leaks into the surrounding eyelid tissue and triggers a granulomatous reaction. Histology shows lipogranulomatous inflammation with epithelioid histiocytes, multinucleated giant cells, and lipid vacuoles. It is not primarily infectious.

**Clinical presentation:** - Painless, firm, slowly enlarging nodule within the eyelid, usually over weeks. It may start with mild tenderness and erythema. - It is located deep in the lid, within the tarsal plate. It can be on the upper or lower lid and points toward the conjunctival side. - Large lesions can press on the cornea, causing astigmatism and blurred vision. - There are no signs of acute infection, such as warmth or purulence.

**Chalazion vs. hordeolum (high-yield):** - *Chalazion:* meibomian gland, chronic, painless, sterile granuloma, deeper in the lid. - *External hordeolum (stye):* infection of the gland of Zeis (sebaceous) or gland of Moll (apocrine sweat), usually *Staphylococcus aureus*. It is acute, painful, and at the lid margin, often at the base of an eyelash. - *Internal hordeolum:* acute infection of the meibomian gland. It is painful and can progress to a chalazion.

**Risk factors/associations:** - Blepharitis (including seborrheic) and meibomian gland dysfunction - Acne rosacea - Seborrheic dermatitis - Diabetes - Prior chalazia - Viral infections - Poor lid hygiene

**Red flags:** A recurrent or atypical chalazion in the same location, especially in an older adult, with lid margin distortion, loss of lashes (madarosis), or a yellowish thickening, should prompt biopsy to rule out **sebaceous gland carcinoma**. This is a classic masquerade syndrome. Other masqueraders are basal cell carcinoma and lymphoma.

**Management:** 1. Conservative (first line): warm compresses several times daily, lid massage, and lid hygiene. Many resolve in weeks to a few months. 2. Persistent lesions (more than 4–6 weeks) or those affecting vision: intralesional triamcinolone injection, or incision and curettage. Incise through the conjunctival side to avoid a skin scar and lid notching. 3. Antibiotics are generally not needed unless there is secondary infection or associated blepharitis. 4. Send recurrent lesions for histopathology.

**Boards pearl:** A painless, non-tender, firm eyelid nodule that persists after a stye resolves is a chalazion. Think sebaceous carcinoma if it recurs in an older patient.