Abstract:AIM: To analyze the possible risk factors in the development of seasonal allergic conjunctivitis (SAC) through an evaluation of skin allergy tests and data obtained from questionnaires. METHODS: The study included a total of 75 SAC patients and 71 control subjects without SAC diagnosis who were admitted to the Abant Izzet Baysal University Medical Faculty Ophthalmology Clinic between March 2016 and December 2016. Skin prick tests were performed for all participants. Serum levels of total IgE and 25-OH vitamin D were also measured. In the tear, total IgE levels were measured. Moreover, possible risk factors for the onset of SAC (smoking, paracetamol exposure, vitamin D supplementation and environmental factors etc.) were examined for all patients by both prenatal and postnatal aspects. RESULTS: The patients with SAC were found to have a history of maternal paracetamol exposure during the prenatal period. Likewise, in the same patient group, the duration of postnatal vitamin D supplementation was shorter (P<0.001). However, no significant correlation was found between SAC and maternal antibiotic exposure, maternal smoking, the mode of delivery and birth weight, as well as presence of pets. Moreover, patients with SAC were more likely to have asthma, allergic rhinitis and oral allergy syndrome. We have also found that SAC patients’ mothers and siblings were more likely to have allergic conjunctivitis. Likewise, their fathers were more likely to have allergic rhinitis. CONCLUSION: Prenatal maternal paracetamol exposure and shorter duration of vitamin D supplementation in the postnatal period may play a role in development of SAC. Therefore prevention of unnecessary gestational paracetamol intake and vitamin D supplementation during infancy could potentially reduce the onset and development of SAC.