59 yo Female c/o itchy nose but more tingling nose, lightheadedness, weakness to the point that she has to sit down. Pt thinks this may be related to Histamine in foods, b/c she notices that Benadryl helps and initially thought nose was itchy. No flushing. Her husband has noted her blood pressure seems to drop and her heart rate increases then. The episodes started about 9 months ago, and can have several in the same day and subsequent days. Can disappear for one month and then recur. Recent episode started with 10 episodes that day, each lasting 15-30 seconds only. Last year, she passed out and found herself on kitchen floor. Benadryl 25-50 mg q4 hrs prevents future episodes that day or later that week if she continues the Benadryl.
Food Allergies-Known Triggers: Occurred once after shrimp and avoiding all seafood since. Also was eating a trail mix daily with dried cranberries and dried cherries, tree nuts but after syncope, stopped since then. Does not drink wine. She is afraid of eating foods and therefore is losing weight. Avoids egg, shrimp, fish, yogurt, yeast, bread.
Lab results: Normal CMP, CBC diff; IGE total; TSH, ANA, SIGE to shrimp, wheat, yeast, ovalbumin and ovomucoid. DURING episode, had Normal Serum total catecholamines, complement, Histamine, normal Urine 5 HIAA and tryptase NORMAL.
ABNORMAL: low serum serotonin 28 (56-244)
Assessment: Episodes of lightheadedness, tingling, and syncope.
Do you think this is food related or other? It may not be an allergy issue but thinking of who to refer her to.