When the immune system reacts to similar allergens
pollen allergy sufferers should be careful with these foods
The immune system reacts to two different substances that are very similar in structure. For example, it is possible that the immune system not only overreacts to wormwood pollen, but that an allergic reaction also occurs after eating celery, tomatoes or peppers.
Cross allergies are among the food allergies most common in adults. They are particularly common in allergy sufferers who react to so-called early bloomers such as hazel, alder and birch. Because they often go hand in hand with a pollen allergy, they are also called pollen-associated food allergies.
Primary and secondary food allergies
In principle, a distinction is made between primary and secondary allergies in food allergies.
Which foods trigger cross allergies?
Numerous fruits and vegetables, nuts, legumes and grains can cause cross allergies. In general, the more natural (unprocessed) a food is, the greater the chance that it will also trigger an allergic reaction.
Tree pollen (birch, alder, hazel)
Fruits: apple, kiwi, nectarine, cherries, peaches, plums, pears, almonds, lychees
Vegetables: raw potatoes, carrots, celery
Nuts: hazelnuts, walnuts
Grass pollen and grain pollen (wheat, rye)
Grain: wheat, rye, spelt, barley, oats, millet, maize
Various flours, clays
Fruit: melon, kiwi, mango, wine grapes, lychees
Vegetables: potatoes, bell pepper, celery, tomatoes, carrots
Spices/herbs: cumin, anise, coriander, fennel seed, parsley, pepper or paprika
Fruit: banana, melon
Vegetables: cucumber, zucchini, salad
What are the symptoms of a cross allergy?
A cross-allergy usually manifests itself in mild and topical limited symptoms that appear a few minutes to two hours after eating certain foods. Typical signs of food allergy are:
- Swellings and blisters on the oral mucosa (oral allergy syndrome)
- Itchy stimulus on the lips, tongue, palate, ears and pharynx
- Swelling, red spots and bumps on the skin
- Allergic asthma
- Sniffle, sneeze
Our immune system can’t distinguish whether the proteins are those of birch or apple. It only recognizes the allergen as dangerous – and a cross-reaction occurs.
A serious allergic reaction is rare, but it is certainly possible. For example, when an allergy sufferer has ingested a large amount of the allergen.
When do the symptoms of a cross allergy occur?
In some cases, the symptoms of a cross-allergy only occur when the inhalant allergen is also rampant. In autumn and winter, the foodstuffs concerned can then be eaten again without any problem. In other cases, the intolerance persists throughout the year.
How is the cause of a cross allergy diagnosed?
A history is often the key to diagnosing a cross allergy. The doctor first talks to the patient about his eating habits and the complaints.
If a diagnosis cannot be made on the basis of the conversation alone, the doctor may ask the patient to keep a food diary. In it, he/she records his meals and also when which symptoms occurred. This diary helps the doctor determine the cause.
If a suspected cause can then be derived from this, this suspicion can in turn be checked with a so-called skin prick test or a blood test. If these tests are also unsuccessful, the doctor can perform an oral challenge test under special supervision.
How is a cross allergy treated?
Also with food allergies, a “waiting time” (avoiding exposure to the suspected allergen) can ensure that an allergic reaction does not even break out. If you know which food triggers the reaction, you should avoid it. With vegetables, it may be sufficient to cook the food instead of eating it raw.
The acute signs of a cross-reaction are treated symptomatically, as with other allergies, to relieve the symptoms. There are various products for this that are available without a prescription, for example anti-allergics or nasal ointments and nasal douches against sniffling.
Only desensitization or allergy immunotherapy is suitable for a lasting improvement. This fights the cause of the allergy.
Cross allergies – what can you do?
Allergy sufferers can pay attention to a few points in their diet to limit their suffering.
Cooking off foods
Choosing the right kind
Avoiding alcohol Avoiding
Choosing the right kind
Not all kinds of fruit elicit an allergic reaction to the same degree with certain fruits. For apples, for example, the Hammerstein, Gloster and Altländer apple varieties are known to be well tolerated.
alcohol Alcohol can intensify the allergic reaction. So it is best for people with a cross allergy to abstain from alcohol.
stress The stress and strain of everyday life can have a negative influence on an allergic reaction. Sport, enough sleep, relaxation techniques and conscious living can help to get stress under control.