Although the terms chalazion, stye, and hordeolum are used interchangeably, they refer to two different, yet related, conditions.

• A hordeolum, also known as a stye, is a local, acutely inflamed lesion of the eyelid. It occurs near the lid margin or farther up the lid on either the tarsal or skin side of the eyelid.
• A chalazion is the chronic form of a hordeolum, and its cellular makeup is composed of chronic inflammatory cells. Both the meibomian and sebaceous oil glands of the lid can be involved in this process, which begins with a blockage of the normal openings of these glands, leading to the swelling. Chalazia are often recurrent.

There may be bacterial contamination and infection, especially in hordeola. These infections are generally caused by Staphylococcus species and may be associated with blepharitis. Pain, tenderness, swelling, and discharge from the lesion may all be noted by the patient.

Hordeola may occur in any population. Chalazia are more common in adults and men.

Patients with rosacea, seborrheic dermatitis, psoriasis, and blepharitis, or any long-term inflammation of the eyelid, are especially at risk for hordeolum or chalazion.