Frequency distribution | Food allergy

Frequency distribution

Food intolerances occur relatively frequently. For example, about 10% of the population suffer from lactose intolerance. The clinical picture of food allergy described here occurs much less frequently. 1.5 % of adults suffer from food allergy, food allergy is more frequent in infants.

Symptoms

Characteristic are reactions of the mucous membranes, more precisely swelling and itching of the mucous membranes of the mouth, nose and throat, as well as gastrointestinal complaints such as nausea, vomiting, flatulence, cramp-like abdominal pain and diarrhoea. In addition, asthmatic complaints with swelling of the bronchial mucous membranes and consequent shortness of breath can occur. Skin reactions manifest themselves as rashes and redness (exanthema and eczema), hives and itching.

Conjunctivitis of the eyes with redness, swelling and severe itching as well as increased sensitivity to light can also occur. Other symptoms may include fever and inflammation of the joints (arthritis). Symptoms of food allergy typically appear immediately after ingestion of the food against which hypersensitivity exists.

The skin may be reddened and itching may occur. Less frequent symptoms on the skin include acute urticaria (hives) or neurodermatitis (atopic dermatitis). Acute urticaria is defined as hives that do not persist for more than 6 weeks.

Patients with acute urticaria complain of extraordinary itching and have visible wheals. The clinical picture is similar to that after accidentally touching nettles. If neurodermatitis is caused by food allergy, red, scaly and sometimes weeping eczema is the main symptom, which appears in phases.

Food allergies are mainly characterized by symptoms of the gastrointestinal tract. Classically, symptoms first appear in places at the beginning of the food passage. This means that initially there may be complaints in the oral cavity, such as swelling.

A few hours after eating, nausea and vomiting may also occur. Finally, cramp-like pain (colics) and diarrhea are also possible, which can appear up to 6 hours after ingestion of the food. Complaints with the respiratory tract occur mainly in the context of anaphylactic shock.

This is the maximum of the hypersensitivity reaction of our immune system and is acutely life-threatening. In the course of the anaphylactic shock, respiratory distress is in the foreground.Even chronic asthma can be attributed to a food allergy in about 10% of cases. It is also worth mentioning that various factors are known to aggravate the symptoms of a food allergy.

These primarily include psychological stress, physical exertion and the consumption of alcohol. If infants and toddlers suffer from a food allergy for a long period of time, it can manifest itself as a growth disorder. In such cases, a deviation from the age-typical height and weight can be seen.

It is important that in such cases a pediatrician is consulted so that it can be found out what is the real cause of the growth disorder. A symptom that very often occurs in the context of food allergies is diarrhea, which occurs about one to two hours after consumption of the respective allergen. It is usually preceded by symptoms such as nausea and cramp-like abdominal pain.

The diarrhea itself is usually very runny, since the too short intestinal passage does not allow sufficient water absorption through the colon mucosa. However, the consistency of the diarrhea can also be of a different nature and thus possibly provide information about the causative food allergen. For example, the sprue (also called celiac disease) caused by the gluten protein gluten is characterized by mushy, malodorous diarrhea.

A treatment of the diarrhea should be primarily causal. Ultimately, this means that the affected person should refrain as far as possible from using the food allergens specific to him or her. About half of all food allergy sufferers are affected by a skin rash (exanthema).

It is therefore the most common symptom of the food allergy clinical picture. The skin symptoms typical of a food allergy can be varied and range from extensive reddening of the skin, swelling (edema), fine-bubble rash to hives (urticaria). Treatment of the skin rash is possible, but usually not necessary, as it is self-limiting with the excretion of the responsible allergen and thus subsides within hours or days.

If a therapy is nevertheless desired, it can possibly be carried out by applying an ointment containing cortisol. Even if the exact mechanisms are not yet known, the skin can be affected by an allergy in many ways. For example, the development of pimples or other skin impurities can also be favored by an allergic reaction.

This is supported by the hypothesis that an allergic reaction releases inflammation-promoting messenger substances. These can then also contribute to the development of skin impurities. A good indication for the development of skin impurities through a food allergy is that the skin impurities decrease as soon as the suspected food is no longer consumed for some time.