<unk>  is characterized by inflammation of the eyelid margins.<unk>  may be classified according to the anatomic location of the disease into 2 subtypes: anterior and posterior. Additionally,<unk>  may be classified based on the duration of symptoms into either acute or chronic.
The exact pathogenesis of<unk>  is not fully understood. 
It is thought that<unk>  is caused by either bacterial colonization (Staphylococcus aureus or Staphylococcus epidermidis) in the eyelids or meibomian gland dysfunction.<unk>  may also caused by allergens and mites that affect the eyelashes.<unk>  must be differentiated from conjunctivitis, trichiasis, dry eye syndrome, keratitis, hordeolum, and chalazion.<unk>  is usually asymptomatic until the disease progresses. As it progresses, the patient begins to notice a foreign body sensation, itching, irritation, and crusting of the eyelids.<unk>  can frequently be improved but is rarely eliminated. If left untreated, severe<unk>  may cause loss of eyelashes, scarring of the eyelids, corneal involvement, and ultimately blindness. Common complications of<unk>  include loss of eyelashes, hordeolum, chalazion, corneal ulcer, and conjunctivitis.<unk>  is associated with a favorable long-term prognosis.
Physical examination of patients with<unk>  is usually remarkable for irritated eyelid edges, crusting of the lashes, entropion, ectropion, poliosis, and diffuse conjunctival injection.
In general,<unk>  is diagnosed based on clinical features alone.
There are no diagnostic lab findings associated with<unk> .<unk>  is diagnosed based on clinical features alone.
Eyelid hygiene and regular cleaning are the mainstay of therapy for<unk> . 
Antimicrobial topical therapy may be indicated in some cases depending on the causative pathogen and the underlying cause.
Blepharitis
Periorbital cellulitis
Orbital cellulitis
Corneal ulcer
Trachoma
Angular cheilitis
Superior limbic keratoconjunctivitis
Blepharochalasis