<unk>  is characterized by chronic inflammation of the eyelid, usually at the base of the eyelashes. Symptoms include inflammation, irritation, itchiness, a burning sensation, excessive tearing, and crusting and sticking of eyelids. Additional symptoms may include visual impairment such as photophobia and blurred vision. Symptoms are generally worse in the mornings and patients may experience exacerbation and several remissions if left untreated. It is typically caused by bacterial infection or blockage of the meibomian oil glands. Diseases and conditions that may lead to<unk>  include: rosacea, herpes simplex dermatitis, varicella-zoster dermatitis, molluscum contagiosum, allergic dermatitis, contact dermatitis, seborrheic dermatitis, staphylococcal dermatitis, demodicosis (Demodex), and parasitic infections (e.g., Demodex and Phthiriasis palpebrarum). The parasite Demodex folliculorum (D. folliculorum) causes<unk>  when the parasite is present in excessive numbers within the dermis of the eyelids. These parasites can live for approximately 15 days. The parasites (both adult and eggs) live on the hair follicle, inhabiting the sebaceous and apocrine gland of the human lid. Direct contact allows this pathogen to spread. Factors that allow this pathogen to multiply include hypervascular tissue, poor hygienic conditions, and immune deficiency. In treating<unk>  caused by D. folliculorum, mechanical cleaning and proper hygiene are important towards decreasing the parasites numbers. Scaling and bacterial debris at the base of the eyelashes Associated symptoms * Watery eyes – due to excessive tearing. * Red eyes – due to dilated blood vessels on the sclera. * Swollen eyelids – due to inflammation. * Crusting at the eyelid margins/base of the eyelashes/medial canthus, generally worse on waking – due to excessive bacterial buildup along the lid margins. * Eyelid sticking – due to crusting along the eyelid margin. * Eyelid itching – due to the irritation from inflammation and epidermis scaling of the eyelid. * Flaking of skin on eyelids – due to tear film suppressed by clogged meibomian glands. * Gritty/burning sensation in the eye, or foreign-body sensation – due to crusting from bacteria and clogged oil glands * Frequent blinking – due to impaired tear film from clogged oil glands unable to keep tears from evaporating. * Light sensitivity/photophobia * Misdirected eyelashes that grow abnormally – due to permanent damage to the eyelid margin * Eyelash loss – due to excessive buildup of bacteria along the base of the eyelashes. * Infection of the eyelash follicle/sebaceous gland (hordeolum) * Debris in the tear film, seen under magnification (improved contrast with use of fluorescein drops) External hordeolum Chronic<unk>  may result in damage of varying severity and, in the worst cases, may have a negative effect on vision. This can be resolved with a proper eyeglass prescription. Long-term untreated<unk>  can lead to eyelid scarring, excess tearing, difficulty wearing contact lenses, development of a stye (an infection near the base of the eyelashes, resulting in a painful lump on the edge of the eyelid) or a chalazion (a blockage/bacteria infection in a small oil glands at the margin of the eyelid, just behind the eyelashes, leading to a red, swollen eyelid), chronic pink eye (conjunctivitis), keratitis, and corneal ulcer or irritation. The lids may become red and may have ulcerate, non-healing areas that may lead to bleeding.<unk>  can also cause blurred vision due to a poor tear film. Tears may be frothy or bubbly, which can contribute to mild scarring along the eyelids. Symptoms and signs of<unk>  are often erroneously ascribed by the patient as "recurrent conjunctivitis". Staphylococcal<unk>  and posterior<unk>  or rosacea-associated<unk>  symptoms Symptoms include a foreign body sensation, matting of the lashes, and burning. Collarette around eyelashes, a ring-like formation around the lash shaft, can be observed. Other symptoms include loss of eyelashes or broken eyelashes. The condition can sometimes lead to a chalazion or a stye. Chronic bacterial<unk>  may also lead to ectropion. Posterior<unk>  or rosacea-associated<unk>  is manifested by a broad spectrum of symptoms involving the lids including inflammation and plugging of the meibomian orifices and production of abnormal secretion upon pressure over the glands.
Blepharitis
Periorbital cellulitis
Capillaritis
Ocular larva migrans
Orbital cellulitis
Sympathetic ophthalmia
Periorbital dermatitis
Corneal ulcer