This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Conjunctiva, Subject name: Ophthalmology
After a leisure trip, a patient comes with gritty pain in eye and joint pain. What is the most probable diagnosis? 
Select and explain. 
A. Reiter's syndrome, B. Behcet's syndrome, C. Sarcoidosis, D. SLE
A: Reiter's syndrome
Answer: A: Reiter's syndrome 
Explanation: Joint pain is a feature of Reiter's syndrome. It's a triad of urethritis, ahritis and conjunctivitis. It is causes by Chlamydia(m/c), Salmonella, Yersinia, Campylobacter, Ureaplasma, Shigella OTHER OPTIONS: Behcet syndrome: inlude mouth and genital soresa, inflamed eyes and rashes. Sarcoidosis: symptoms vary depending on the organs affected SLE : can affects skin, kidney, joints, brain and other organs.