While it may seem counter-intuitive, certain foods can worsen antihistamine allergy symptoms due to a phenomenon known as cross-reactivity. This is where the proteins in certain foods closely resemble those in allergens - in this case, sk chemicals like histamines.

Foods Containing High Levels of Histamines

• Cheese: Aged cheeses have been shown to carry vast amounts of histamine.
• Alcohol: Alcoholic beverages, particularly wine, champagne, and beer, contain high levels of histamine.
• Fermented Foods: Foods such as sauerkraut, vinegar, soy sauce, kefir, yogurt, and fermented sausage like salami contain significant histamine levels.

Foods Causing Histamine Release

• Citrus Fruits: Oranges, lemons, limes, and grapefruit can trigger the body to release histamine.
• Chocolate: Cocoa beans, used in the manufacturing of chocolate, are known to cause histamine release.
• Cow Milk: Cow milk and certain other dairy products can stimulate histamine release.

Foods which carry Natural Source of Histamine

• Fish: Tuna, mackerel, mahi-mahi, sardines, and anchovies are some of the fish known for their high histamine content.
• Spinach: Spinach is another food high in histamines.
• Tomatoes: Tomatoes, along with tomato-based products and sauces, contain significant amounts of histamine.

Note that individual responses to these foods vary, and not every person with an antihistamine allergy will react to all or any of these foods. It is advisable to seek professional medical advice for managing allergies.