Symptoms of histamine intolerance include nausea, hives, headaches, hypertension and changes in heart rate, according to mindbodygreen. Histamine intolerance may cause a runny nose or itchy tongue after eating eggplants, avocados or bananas. Other symptoms are irregular menstrual cycles, anxiety, fatigue and congestion.
Histamine is a naturally occurring substance in the body that works as part of the immune system, explains mindbodygreen. Histamine intolerance sometimes results if levels rise too high, which may occur due to gastrointestinal bleeding, allergies, bacterial imbalance, certain foods or low levels of an enzyme called diamine oxidase. Consuming foods or beverages that contain histamine, or cause the body to increase histamine levels, may cause a reaction. Foods that block diamine oxidase in the digestive tract can cause symptoms of histamine intolerance.
Doctors use lab tests to check histamine and diamine oxidase levels in individuals who experience symptoms of histamine intolerance, according to mindbodygreen. Treating histamine intolerance revolves around discovering and addressing the root cause, which may be medications, digestive conditions or diet. Doctors sometimes recommend eliminating particular foods and beverages from the diet and supplementing the body's diamine oxidase production with two enzyme pills at each meal. Once enzyme and histamine levels return to normal, patients can usually return to a normal diet.