Phlyctenular keratoconjunctivitis results from a hypersensitivity reaction to bacterial antigens, primarily staphylococcal, but tuberculosis (TB), Chlamydia, and other agents have been implicated. It is more common among children. Many patients also have blepharitis Blepharitis Blepharitis is inflammation of the eyelid margins that may be acute or chronic. Symptoms and signs include itching and burning of the eyelid margins with redness and edema. Diagnosis is by history... read more 
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Patients have multiple lesions, consisting of small yellow-gray nodules (phlyctenules) that appear at the limbus, on the cornea, or on the bulbar conjunctiva and persist from several days to 2 weeks. On the conjunctiva, these nodules ulcerate but heal without a scar. When the cornea is affected, severe lacrimation, photophobia, blurred vision, aching, and foreign body sensation may be prominent. Frequent recurrence, especially with secondary infection, may lead to corneal opacity and neovascularization with loss of visual acuity.
Diagnosis is by characteristic clinical appearance. Testing for TB Diagnosis Tuberculosis is a chronic, progressive mycobacterial infection, often with an asymptomatic latent period following initial infection. Tuberculosis most commonly affects the lungs. Symptoms include... read more 
may be indicated (eg, for patients at risk).
Treatment for nontuberculous cases is with a topical corticosteroid–antibiotic combination. Treatment reduces the pain within hours and prevents scarring and decreased vision. If patients have seborrheic blepharitis Blepharitis Blepharitis is inflammation of the eyelid margins that may be acute or chronic. Symptoms and signs include itching and burning of the eyelid margins with redness and edema. Diagnosis is by history... read more , eyelid scrubs may help prevent recurrence.
