In anterior blepharitis, which of the following is typically involved?

Anterior blepharitis primarily involves the skin at the base of the eyelashes. This condition typically presents as inflammation of the eyelid margins, which can be caused by seborrheic dermatitis or bacterial infections, particularly staphylococcal infections. In anterior blepharitis, the inflammation frequently manifests as crusting, redness, and irritation specifically at the eyelid margins and around the eyelashes, making the area at the base of the eyelashes the focal point of involvement.

In contrast, other structures such as the Meibomian glands, which are located deeper in the eyelids, are affected in posterior blepharitis, where there is inflammation of these glands leading to issues with oil secretion. The conjunctival surface is more related to conjunctivitis rather than blepharitis. The deep tissue of the eyelid is not typically involved in anterior blepharitis but can be associated with other conditions like orbital cellulitis or deeper infections. Thus, the specific involvement of the skin at the base of the eyelashes is key to understanding anterior blepharitis and its clinical presentation.