Which type of blepharitis is most common?

The most common type of blepharitis is anterior blepharitis. Anterior blepharitis primarily affects the outer part of the eyelid, where the eyelashes are located, and is often caused by seborrheic dermatitis or staphylococcal infection. This condition generally presents with symptoms such as redness, scaling, and crusting around the eyelash base, which can lead to discomfort or irritation.

In contrast, posterior blepharitis involves the meibomian glands situated along the inner eyelid and is frequently associated with meibomian gland dysfunction or inflammation of the glands. Although posterior blepharitis is also common, it is not as prevalent as anterior blepharitis.

Chalazion and dacryocystitis are not types of blepharitis; a chalazion is a blockage of a meibomian gland leading to a cyst formation, while dacryocystitis involves inflammation of the lacrimal sac, usually due to infection. As a result, these conditions are different in nature and presentation from blepharitis, further emphasizing the distinction between the types of lid issues.