Which condition is characterized by painful, acute bacterial infection of the eyelid hair follicle?

The condition characterized by a painful, acute bacterial infection of the eyelid hair follicle is indeed hordeolum, commonly known as a stye. This condition specifically arises when the hair follicle of an eyelash becomes infected, leading to the formation of a red, swollen bump on the eyelid associated with pain and tenderness. The source of infection is typically due to bacteria, such as Staphylococcus aureus.

A chalazion, although it can appear similar to a hordeolum, is actually a result of a blocked Meibomian gland and is not usually associated with acute pain or infection. Instead, it tends to be a painless swelling on the eyelid.

A meibomian cyst refers specifically to a blockage of the oil glands, leading to a lump that is generally not painful and is often regarded as a chronic condition.

Pterygium, on the other hand, is a growth of tissue on the conjunctiva of the eye, often triggered by UV exposure and environmental factors. It typically does not present with the acute pain seen in hordeolum or exhibit the characteristics of an infectious process.

In summary, hordeolum is directly linked to an acute bacterial infection of the eyelid