Watermelon allergies are uncommon. However, if a person reacts to this fruit, there may still be additional foods to avoid. The symptoms are also similar to those of other food allergies and it can be determined by performing several tests. A watermelon allergy usually develops during childhood but some people get it during adulthood.

Symptoms

Watermelon allergies share symptoms with other food allergies. Symptoms usually occur within a few minutes of contact with the fruit. Some of these include:

• persistent coughing
• hives
• itchy tongue or throat
• stomach ache
• nausea or vomiting

Like other allergies, an allergy to watermelon can also trigger anaphylaxis, which is life-threatening. Symptoms of which include difficulty breathing and swallowing, shortness of breath, swelling of the throat, face, and tongue, nausea, wheezing, shock (from low blood pressure) and vertigo or a feeling of dizziness.

Anyone experiencing these symptoms should receive immediate medical attention.

Diagnosis

Doctors usually perform a skin prick test to diagnose this kind of allergy. A skin prick test involves pricking the skin and placing a small sample of watermelon on the area. A raised bump will appear on the skin after a few minutes if the person is allergic. They may also order a blood test but it takes a few days before the results come out, or a challenge test, which requires the person to eat a small amount of food in a clinical setting to see if a reaction occurs.

However, some people may test positive for an allergy but experience no symptoms from the food, according to the American College of Allergy, Asthma, and Immunology. 

Treatment

Usually, over-the-counter medications can treat a mild allergic reaction. People with severe allergy to watermelon should carry an epinephrine auto-injector in case of accidental exposure. Call emergency medical services when you see someone who is experiencing anaphylaxis. 

See a doctor at first sign of an allergic reaction, so you will be given proper advise and treatment, and referral to an allergist if necessary. 

Foods to Avoid

Anyone allergic to watermelon should avoid similar foods and vegetables such as honeydew melons, cucumbers, cantaloupes. People with watermelon allergy may also want to avoid foods that cause similar reactions including kiwi, celery, peaches, bananas, oranges, avocados, zucchini, tomatoes, and papayas, among others. Ragweed pollen can also trigger reactions during the summer months.