Which condition is highly associated with blepharitis?

Blepharitis is an inflammation of the eyelid margins and is often associated with seborrheic dermatitis and conditions that affect the skin, particularly those that cause changes in oil gland function. Rosacea significantly influences the eyelid area and can lead to symptoms consistent with blepharitis, including redness, irritation, and crusting of the eyelid margins. The chronic inflammation and increased oil production associated with rosacea can exacerbate or contribute to the development of blepharitis by leading to obstruction of the meibomian glands.

In contrast, while bacterial conjunctivitis and herpes simplex virus can cause conjunctival symptoms, they are not directly linked to the eyelid margin inflammation characteristic of blepharitis. Sarcoidosis, a systemic granulomatous disease, may also affect the eyes but has less direct association with blepharitis compared to the skin-related condition of rosacea. Thus, rosacea stands out as the most relevant condition associated with blepharitis due to its similar inflammatory mechanisms and the effects on the eyelid margins.