Cross-allergies occur more frequently in connection with hay fever. Those who suffer from a pollen allergy, not only have to do without spring walks - often even a bite into an apple or eating a peanut for allergic people can have serious consequences. Because with them, the immune system reacts hypersensitive to foreign substances, the so-called allergens. Since some allergens, for example the allergens of pollen, are similar to those of some foods, allergy sufferers can develop so-called cross-allergies. Often it is certain fruit, vegetable or nut varieties that cause such a cross allergy.
Hay fever: trigger of cross-allergies
Hay fever is often referred to as pollen allergy because it is triggered by pollen from grasses, trees or herbs. Depending on which substances cause the allergy, the intensity of the symptoms may vary seasonally:
- Usually the pollen load is highest in the spring and summer months.
- Already in February or March awake the first Frühblüher, to which among other things the alder and the hazel belong.
- As the year progresses, allergy sufferers are especially troubled by pollen from the birch.
- The flowering period of the grasses, however, typically ranges from May to August, so that an allergy to rye or oats sometimes makes itself felt only in the summer months.
One of the most allergenic substances is mugwort. This weed can cause very severe discomfort even in small amounts.
Since the allergy can spread to the bronchi and cause allergic asthma there, all cases of hay fever should be treated professionally by the allergist. This should also check whether the hay fever is associated with a cross-allergy.
What is a cross-allergy?
The allergens of pollen and some foods are partly similar in their chemical structure. Since the immune system can not always distinguish the individual substances from one another, pollen allergy sufferers are often sensitive to certain foods. This is called "cross allergy" or "pollen-associated food allergy".
However, cross-allergies occur not only in connection with hay fever - other allergies come as a trigger in question.
Common forms of cross-allergy
Which foods cause discomfort depends on the nature of the allergy:
- Often there is a cross allergy between tree pollen and various types of fruit, vegetables, nuts and herbs.
- Those who are allergic to birch pollen often also show symptoms of eating stone and pome fruit (for example apple, pear, cherry, plum or peach), strawberries, tomatoes, hazelnuts or soybeans.
- There is also a relationship between mugwort pollen and certain spices, such as cumin, pepper or anise, but also with vegetables such as paprika, celery, carrot or cucumber.
- Grass pollen allergies often cause hypersensitivity to other crops as well as various types of fruits, vegetables, nuts and spices (for example, rye, oats, melon, kiwi, peas, peanut or peppermint).
- House dust allergies are often associated with a cross-reaction to shellfish or crustaceans.
- Also cross-reactions between similar foods are possible, for example between different types of nuts, cereals or fish.
- An allergy to penicillin can lead to a cross allergy to a certain group of antibiotics.
There is also a link between contact and food allergens. A typical example of a contact allergy is the latex allergy. This allergy form is often associated with an allergy to nuts, fruits (for example, avocado, banana or kiwi) or vegetables (for example, potato, celery or tomato).
How is a cross-allergy noticeable?
The symptoms of a cross allergy usually occur immediately after eating and are usually local to the mouth area limited.
For example, the following symptoms may occur:
- Swelling, tingling or itching of the oral mucosa
- Blistering on the lips
- Skin redness around the mouth
Only rarely does the allergy spread to the entire body. In these cases, the following symptoms may occur:
- Discomfort in the gastrointestinal area
- Circulation problems
- difficulty in breathing
In the worst case, there is a risk of circulatory collapse, acute respiratory distress or even a life-threatening allergic shock.
Treatment of a cross allergy with antihistamines
Medications can relieve the symptoms of cross-allergies. Antihistamines, for example, reduce the effect of the body's own messenger histamine. This is released in an allergic reaction to a high degree and triggers the typical symptoms.
Depending on the active ingredient, antihistamines are available as a nasal spray, eye drops, tablets, syrup or drops. They not only relieve the symptoms of cross-allergy but are also used to treat hay fever. Occasionally, however, they can cause fatigue as a side effect.
Hyposensitization in cross-allergies
The cause of a cross-allergy can only fight a so-called hyposensitization. The aim of this treatment is to gradually get used to the immune system to the allergens. For several years, the patient is given the specific allergen at regular intervals - usually via a syringe. The dose is increased over time.
Although this form of therapy is tedious, but can counteract the cause of allergy as the only known method. The treatment can lead to an improvement of the symptoms or even the complete cessation of the allergy. At least, however, the quality of life of those affected is noticeably improved.
Hyposensitization can be performed in both adults and children. This therapy is recommended especially for patients suffering from hay fever. Autumn is the best time of year to start treatment, as at this time the general pollen load is low.
For serious illnesses, such as asthma, this type of treatment should be avoided.
Do food have to be avoided?
In a cross-allergy is a total waiver of allergenic food is the safest option to avoid the onset of symptoms - because sometimes even small traces of the allergen can cause severe discomfort. However, many foods can be made compatible by heating or prolonged freezing.
Especially fruits and vegetables can be "made harmless" by heating. Also in the form of nutmeg, juice, marmalade or cake, many types of fruit, such as the apple, are generally also tolerated by allergy sufferers.
Other allergens, on the other hand, are heat resistant. This is especially true for nuts, celery, fish, soy and many other animal products. These foods should be avoided altogether in case of allergy.
Often the complaints occur when eating the food, especially when the corresponding pollen have just flight time. In this case, a seasonal waiver of the respective food may be useful.
Always keep an eye on the cross-allergy
As an allergic person, you should be careful about what foods you eat. The focus is always on the question of the ingredients. Especially with finished products, it is sometimes necessary to read the ingredients very thoroughly: So can hide behind labels such as "vegetable oil" or "emulator lecithin", for example, soy.
In order to find alternatives to the allergenic foods, it is advisable to set up a nutrition plan with a nutritionist. This procedure is advisable, especially if certain foods are to be avoided altogether, in order to prevent malnutrition.
In addition, allergy sufferers should be examined at regular intervals by the allergist. Food allergies can become weaker or disappear over time. An allergy test can be used to determine if the allergy is still active.
Keeping a food diary can also reveal which foods might be harmful.
Always with you: the emergency kit
If an allergy has been confirmed or severe reactions have already occurred, it is recommended that you carry an emergency kit. This includes antihistamines, cortisone and an adrenaline spray.
In the event of a so-called allergic shock, in which the person is in a life-threatening state of shock, the medicines contained in the emergency kit should be administered immediately after calling the emergency physician.