This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Phlycten is due to 
Select and explain. 
A. Exogenous allergy, B. Endogenous allergy, C. viral keratitis, D. Fungal keratitis
B: Endogenous allergy
Answer: B: Endogenous allergy 
Explanation: Endogenous allergens in Phlyctenular conjunctivitis are staphylococcus aureus and tuberculosis Refer Khurana 6th edition page number 83