Phlyctenular conjunctivitis is caused by-

Causative allergens 1. Tuberculous proteins were considered, previously, as the most common cause. 2. Staphylococcus proteins are now thought to account for most of the cases. 3. Other allergens may be proteins of Moraxella Axenfeld bacillius and ceain parasites (worm infestation). ref: A K KHURANA OPHTALMOLOGY,E4, Page-77