A watermelon allergy is rare. However, if a person reacts to watermelon, there may be additional foods to avoid.
If a person with an allergy does not eat watermelon often, they may not know what has caused their symptoms. It could be an allergy to a different food, or an unrelated illness.
The symptoms of a watermelon allergy are similar to those of other food allergies. A doctor can perform tests to identify the problematic food.
A watermelon allergy usually develops during childhood, but some people develop it as adults.
Watermelon allergies share symptoms with other food allergies. Symptoms usually occur within a few minutes of contact with the melon.
Some of the most common watermelon allergy symptoms include:
- persistent coughing
- an itchy tongue or throat
- stomach cramps
- stomach pain
- nausea or vomiting
A severe allergic reaction can trigger anaphylaxis, which can be life-threatening.
Anyone experiencing a severe reaction to watermelon should receive immediate medical attention. They may require an injection from an epinephrine auto-injector, such as an EpiPen, before help arrives.
Symptoms of anaphylaxis include:
- trouble breathing
- trouble swallowing
- shortness of breath
- swelling of the throat, face, or tongue
- abdominal pain
- shock (from low blood pressure)
- vertigo (a feeling of dizziness)
Anyone experiencing a watermelon allergy for the first time should talk to a doctor. The doctor can confirm the diagnosis and provide suggestions about treating and preventing future reactions.
A skin prick test is the most common way to diagnose a watermelon allergy.
The test involves pricking the skin and placing a small sample of watermelon on the area. If a person is allergic, a raised bump is likely to appear on the skin after a few minutes.
Results of a blood test can also indicate an allergy. However, it can take a few days or weeks to receive them.
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.
A doctor may request a challenge test, which requires a person to eat a small amount of the food in a clinical setting to see if a reaction occurs.
An individual can usually treat a mild allergic reaction with over-the-counter medication.
If a person knows that they have a severe allergy to watermelon, they should carry an epinephrine auto-injector, in case of accidental exposure.
Anyone who witnesses someone experiencing anaphylaxis should:
- call emergency medical services
- assist in using an epinephrine auto-injector
- help the person remain calm
- remove restricting clothes, particularly those around the throat
- lay the person flat with their feet elevated
- if the person starts to vomit, turn their head without raising it
- if needed, administer CPR
Do not offer food or drink to a person experiencing anaphylaxis.
If a person has a severe allergic reaction, they should talk to a doctor right away about prescribing an epinephrine auto-injector.
A person should see a doctor after their first allergic reaction, particularly if the reaction was severe.
The doctor will take a medical history and discuss symptoms. They may be able to diagnose an allergy, which will be especially helpful for people who are unsure of the cause of their symptoms.
If necessary, the doctor may refer a person to an allergist. They can test for various triggers, prescribe an epinephrine auto-injector, and offer advice.
Young children are more likely to develop watermelon allergies than adults.
A doctor will need to diagnose the allergy in a child, and the treatments are similar for children and adults.
Though uncommon, it is possible for babies to be allergic to watermelon. Follow a pediatrician's advice, and introduce new foods gradually. This can make identifying allergies easier.
Anyone allergic to watermelon should avoid similar foods and vegetables, such as:
- honeydew melons
A person may also want to avoid foods that cause similar reactions in the body, including:
Ragweed pollen can also trigger reactions during the summer months.
Before ordering a restaurant in a meal, inform the server about any food allergies.
Watermelon allergies are uncommon, but they can trigger reactions ranging from mild to severe. The allergy is most common in children.
Most people can control or prevent allergic reactions by taking over-the-counter medications and avoiding triggers.
A doctor can help a person with a severe allergy to prepare for accidental exposure.