Phlyctenular conjunctivitis is caused by -: (A) Chlaymydia, (B) Staphylococcus, (C) Pneumococcus, (D) Aspergillus
Answer is B. It is believed to be a delayed hypersensitivity (Type IV cell mediated) response to endogenous microbial proteins. Causative allergens are :- (i) Staphylococcus proteins (most common); (ii) Tuberculous proteins and (iii) Proteins of Moraxells axenfeld bacillus and ceain parasistes. Reference : AK Khurana 7th edition page 85