There are 3 main types of blepharitis: Staphylococcal Blepharitis (StB), Meibomian Blepharitis (MB) and Seborrhoeic Blepharitis(SbB). All of the types can cause similar symptoms.
Staphylococcal Blepharitis
This type of blepharitis is assumed to be caused by a bacterium (microbe) called staphylococcus. This microorganism commonly lives in low numbers on the skin while not doing any demage. However, in some people, it looks that this bacterium causes a localised infection of the eye lids, resulting in blepharitis. exactly why this happens in some people is unclear.Meibomian Blepharitis
Meibomian Blepharitis |
This oily fluid forms the outer layer of the tear film that lubricates the front of the eye. Patient with Meibomian Blepharitis are thought to have a small problem with their meibomian glands and the fluid they generate. This may cause eyelid inflammation (This also explains why patient with Meibomian Blepharitis usually have dry eyes as the fluid they make may not be qualify to lubricate the eye).
Seborrhoeic Blepharitis
Seborrhoeic Blepharitis is closely associated with a skin condition known as Deborrhoeic Dermatitis. In Seborrhoeic Dermatitis, make effect skin becomes a lot of oily and can become scaly. Seborrhoeic Dermatitis usually causes bad dandruff and a rash, commonly happen on the face and upper body.The underlying explanation for seborrhoeic dermatitis is not have a clear definition. A type of yeast called "Malassezia Furfur" is involved. However, it's not simply as a simple skin infection and it's not contagious (you cannot catch this condition from others). This yeast lives in the sebum (oil) of human skin in most adults and usually will no harm.
But, in some people the yeast looks to trigger an inflammatory reaction, causing the blepharitis.