Phlycten is due to-: (A) Exogenous allergy, (B) Endogeneous allergy, (C) Viral Keratitis, (D) Fubgal keratitis
Answer is B. Phlyctenular keratoconjunctivitis is a characteristic nodular affection occurring as an allergic response of the conjunctival and corneal epithelium to some endogenous allergens to which they have become sensitized. Phlyctenular conjunctivitis is of worldwide distribution. However, its incidence is higher in developing countries. ref: A K KHURANA OPHTALMOLOGY,E4, Page-77