Walnut belongs to the family of tree nuts. So, when a person is allergic to tree nuts, he might as well be allergic to walnuts but this is not always the case. Sometimes, a person is specifically allergic to walnuts. Walnut allergy is of two types. According to research reports, walnut causes most of the allergic reactions among all other tree nuts.
What is walnut allergy?
Walnut allergy is a hypersensitivity reaction to proteins found in walnuts. It can be categorized into two types on the basis of its manifestation. Walnut allergy is another instance of abnormal immune response.
The primary cause of walnut allergy is malfunctioning of the immune system. The proteins found in walnuts act as allergens and the immune system fails to recognize them as harmless. Instead, they are perceived to pose potential threat to the immune system due to which antibody production is triggered. The immunoglobulin E antibodies engulf the antigens during the consecutive attack by the same allergens and signal the immune system to release histamines and other chemicals. These harmful chemicals trigger allergic response in the body.
Another cause of walnut allergy is linked to tree pollen allergy. It occurs due to cross-reactivity between tree pollen protein and walnut protein.
Symptoms of walnut allergy
Both the categories of walnut allergy depict varied symptoms. The usual kind is marked by anaphylaxis reaction and is potentially severe. The second form of walnut allergy related to tree pollen allergy is usually characterized by mild symptoms.
The first type of walnut allergy includes the following symptoms:
- Severe breathing difficulties
- Abrupt drop in blood pressure
- Nausea or vomiting
- Weak or rapid pulse
- Fainting or loss of consciousness
The second type of walnut allergy includes invariably mild symptoms such as:
- Itchy throat and mouth
- Swelling of mouth, tongue and lips
- Skin reactions such as eczema and hives
- Swelling and redness of the face and other extremities
- Abdominal cramps or pain
- Nausea or vomiting
- Runny nose or nasal congestion
- Troubled breathing
The onset of symptoms takes place immediately after chewing or ingesting walnuts. The severity of symptoms greatly depends on the protein(s) in walnut to which patient is allergic.
Diagnosis & Tests
Since walnut allergy cannot be distinctly identified, therefore, diagnosis is important for confirmation of the presence of allergy. As soon as the symptoms persist, diagnostic center should be approached. Allergists note down the details of family history and symptoms before proceeding with the diagnosis process. Basically, two diagnosis methods are performed to check for the presence of walnut allergy. Those are discussed in detail:
Skin prick test
This test is quite commonly used to figure out if a person is allergic to walnuts. A small portion of the skin is pricked with the help of a needle and a meager amount of suspected allergen extract (in this case, walnut) is incorporated into the pricked portion and waited until any there is any reaction. If red bumps appear, it indicates that the person is allergic to walnuts.
Blood is checked for the presence of immunoglobulin E antibodies. If antibodies are found in the bloodstream, it signifies that the person is suffering from walnut allergy.
Although walnut allergy can happen to anyone yet there are some factors that play pivotal role in increasing the risk of developing the allergy. Such factors are explained in detail:
As walnut allergy is linked to tree pollen allergy, a person having tree pollen allergy symptoms like hay fever is most likely to be suffering from walnut allergy as well.
There is a chance of cross-contamination between walnut and peanut and also between walnut and other tree nuts due to which if a person is allergic to either peanut or some tree nut is at a considerable risk of developing allergy to walnuts.
Asthma or eczema
Prevalence of either asthma or eczema aggravates the possibility of being allergic to walnut allergy.
Younger siblings of children who are allergic to walnuts are at increased risk of developing allergy reactions.
If walnut allergy prevailed in a person sometime in the past, there is likeliness for the allergy to revive at a later point of time.
Walnut allergy is mostly known for causing fatal, life-threatening anaphylaxis reactions. In fact, after peanuts, walnuts are responsible for maximum deaths due to anaphylaxis according to reports. It is always wise to get the allergy diagnosed and treated accordingly at the right time to avoid the hazardous complications of walnut allergy.
Treatment of walnut allergy
The initial treatment of walnut allergy is certainly elimination diet. A walnut allergic patient should avoid walnuts under every circumstance. This is known as preventive treatment. Other treatment processes are adopted to treat the symptoms of walnut allergy. Anti-histamine medications are used to treat the mild symptoms. Anti-histamines are easily available as prescribed and over-the-counter drugs. Anaphylaxis reactions are managed with adrenaline (epinephrine) injections. The patients who are prone to anaphylaxis reactions are advised to carry epinephrine auto-injectors all the time with them. In spite of all the initial line of treatment, a trip to the emergency room is mandatory to treat an anaphylaxis patient completely and monitor the symptoms on a frequent basis.
Diet and caution
A regimented diet devoid of walnuts should be strictly followed by a patient of walnut allergy for which one should be aware of the range of food products that have walnut as essential content. Such food products are:
- Walnut butter
- Ice cream
- Sometimes in Worcester Sauce
- Pickled walnuts
- Walnut oil
Besides avoiding raw walnuts, one should avoid the ones listed above. As a matter of caution, people should always read labels while purchasing any product, whether it is a food product or cosmetic product because many cosmetic products have walnut as ingredient. While dining out at a restaurant, one should be very cautious so that the dish of choice does not contain walnut.