Phlyctenular keratoconjunctivitis is a delayed hypersensitive reaction of conjunctiva and cornea caused by bacterial antigens. It is primarily caused by staphylococcal infections; however, TB, Chlamydia, mycobacterium, tuberculosis, candida albicans as well as parasites can be implicated.

The disease is characterized by multiple small yellow-gray bubble-like nodules (phlyctenules) that form in the limbus, on the conjunctiva and the cornea causing infammation on those tissues. Many patients also develop blepharitis.

The lesions persist from several days to 2 weeks. If the cornea is afected then the nodules will ulcerate, however the ulcers will heal without forming a scar. Other symptoms include excessive lacrimation, photophobia, blurred vision, a foreign body sensation and aching. In general, the disease resolves quickly, yet recurs frequently.

This condition commonly occurs in spring and summer and is most often seen in children and teenagers with poor physique and malnutrition. Females are more susceptible to it than males.

Diagnosis is made visually by its clinical appearance. Testing and cultures to determine the pathogen may be performed. Western medical treatment of nontuberculous cases generally consists of careful cleansing of the eyelid for blepharitis, topical antibiotics and steroidal eye drops. Antibiotics may be prescribed for systemic infections.

In TCM, this disease is referred to as jīn gān (金疳, metal gan). The pathogenesis of this condition is due to dry heat in the lung channel, which disrupts the normal descending and dispersion of qi. Excessive lung fre atacks the eyes, causing qi and blood stagnation. Other factors include defciency of lung yin causing defciency fre to rise upward to the white of the eyes, and dysfunction of the spleen and stomach results in the inability of earth to generate metal, causing a loss of nourishment to the lung channel with dysfunction of lung qi.

The paterns may be defciency or excess and involve the lungs, the spleen, and the stomach.