If you develop allergy symptoms every time you eat basil pesto, you are most likely allergic to one of the ingredients, not the basil. Basil is not a common food allergen and should not cause an allergic reaction. Basil pesto can be made various ways and may contain various ingredients. According to the Food Network, basil pesto may contain milk and tree nuts that can trigger an allergic reaction. If you experience adverse reactions when eating basil pesto, stop eating it until you can see your doctor.
Highly Allergic Ingredients
The two most common allergens in basil pesto are milk and tree nuts, such as pine nuts. These two foods can trigger an allergic reaction, even in small quantities. If you have been diagnosed with a milk or tree nut allergy you should not eat basil pesto. It's important that before you eat anything you know what ingredients are in the food product. If you purchase basil pesto pre-packaged, the manufacturer is required by law to disclose the use of these ingredients.
The majority of all food allergies are to seven basic foods, according to the MayoClinic: peanuts, soy, milk, eggs, wheat, fish and tree nuts. Instead of your immune system recognizing that the proteins in these foods are harmless, the immune system overreacts, causing the body to release different chemicals. Most of the chemicals that are released during an allergic reaction cause swelling, irritation and inflammation in soft tissue. This chemical release is what causes common allergy symptoms.
Symptoms from a food allergy typically affect your digestive system, skin and respiratory system. You may develop diarrhea, vomiting, nausea, rashes, skin irritation, itching, swelling, sinus congestion, sneezing, shortness of breath, difficulty breathing, coughing and wheezing, according to the U.S. National Library of Medicine. A severe allergic reaction will cause your throat to swell and your heart rate to increase and may cause lightheadedness and dizziness.
An adverse reaction after eating basil pesto may not be related to an allergic reaction. If you develop gas, bloating or an upset stomach you may be sensitive to some of the ingredients, such as garlic or olive oil. Make an appointment for further evaluation to diagnose your condition.