A 12-year-old presents with a painful lump in the left eyelid. What is the most likely diagnosis?

In this scenario, a 12-year-old presenting with a painful lump in the left eyelid, the most likely diagnosis is a hordeolum, commonly known as a stye. A hordeolum occurs when there is an acute infection of the oil glands in the eyelid, often leading to a painful, red, and swollen area at the site of infection.

The characteristics of a hordeolum include localized tenderness and the presence of pus-filled bumps that can resemble pimple-like formations on the eyelid. Given the age of the patient and the description of the lump as painful, this typically aligns with the presentation of a hordeolum, which is quite common in children and is often caused by bacterial infection, frequently involving Staphylococcus species.

In contrast, a chalazion is a chronic condition that arises from a blocked sebaceous gland, leading to a firm, usually less painful lump that is often not red or inflamed unless secondary infection occurs. Conjunctivitis involves inflammation of the conjunctiva and typically presents with redness of the eye, discharge, and discomfort instead of a lump on the eyelid. Orbital cellulitis is a serious infection of the tissues surrounding the eye, which may cause more systemic