What causes blepharitis?
There are three main types of blepharitis:
- anterior blepharitis – where the inflammation affects the skin around the base of your eyelashes
- posterior blepharitis – where the inflammation affects your Meibomian glands, found along the eyelid margins behind the base of the eyelashes
- mixed blepharitis – a combination of both anterior and posterior blepharitis
Anterior blepharitis can be caused by either:
- a reaction to Staphylococcus bacteria – these usually live harmlessly on the skin of many people, but for unknown reasons they can cause the eyelids to become inflamed
- seborrhoeic dermatitis – a skin condition that causes skin to become oily or flaky and sometimes irritate the eyelids, causing the Meibomian glands to block
Posterior blepharitis is caused by a problem with the Meibomian glands, where the glands get blocked by either debris, skin flakes or inflammation.
Sometimes blockages in the Meibomian glands are associated with a skin condition called rosacea. If too much oily substance is being produced, this may be caused by seborrhoeic dermatitis.
Mixed blepharitis, which is the most common, is caused by a combination of both anterior and posterior blepharitis.
Blepharitis isn't contagious.