M O N D A Y 643 Profile of Seasonal Differences in Angioedema Presenting to an Inner City Hospital Karyn Winkler, MD, Tukisa Smith, MD, Ashlei Mathew, MD, Rauno Joks, MD; Center for Allergy and Asthma Research, SUNY Downstate Medical Center. RATIONALE: We have previously reported there is a significant increase in angioedema, but not urticaria, in the summer months. In order to further understand this increase, we have investigated the difference in the clinical profiles of patients who are diagnosed in summer months vs. those treated in the winter months. METHODS: A retrospective EMR chart review of the cases of patients treated for angioedema from 2007 to 2012 in either summer (June, July, August) or winter (December, January, February). Data gathered included probable triggers (medication, food, or unknown), body location (face, lips, mouth/throat, and/or extremities/other), duration of symptoms before seeking medical care, and AM or PM presentation at the hospital. Statistical methods included Chi-square test, Fisher’s Exact test, and Mann-Whitney test. RESULTS: A total of 96 cases of angioedema were diagnosed in summer, vs. 65 in winter (p50.015).There was no significant difference in associated triggers between the two seasons (p50.186). There was a significant increase in facial edema occurring with winter presentation (24/ 65) vs. summer (19/65) (p50.016). There was no difference in AM vs. PM presentation (AM summer 49/88 (59%) vs AM winter 34/63 (41%), p50.87) or duration of symptoms (mean6 SD: summer: 2.06 2.2 hours vs. winter 1.6 6 1.6 hours) before presentation (0.09). CONCLUSIONS: Seasonal influence on angioedema includes increase in frequency in summer months and increased facial angioedema in winter months.