Symptoms
Peanut allergy most commonly affects the skin, digestive tract, and respiratory system. Possible symptoms include:
- Rhinitis, stuffy nose
- Itching
- Hives
- Skin redness
- Swelling, angioedema
- Nausea and vomiting
- Abdominal cramps
- Diarrhea
- Cough, whistling breathing
- Tightness in the throat, larynxoedema.
- Voice changes
Peanuts are among the food allergens that most commonly cause severe anaphylactic reactions, which can lead to death if left untreated. Anaphylaxis can cause airway constriction, low blood pressure and cardiac arrhythmias. It should be noted that the course is often biphasic. A second late reaction may follow 1-8 hours after the initial reaction has resolved.
Causes
Peanut allergy is a type I food allergy to peanuts ( L.). Peanuts are consumed roasted and salted on the one hand, but are also present in numerous processed foods as an ingredient or contaminant. Triggers are several so-called Ara-h allergens, which are proteins. The acute symptoms are caused by binding of the allergens to IgE antibodies on mast cells and basophils, which leads to the release of inflammatory mediators. For a severe reaction to occur, oral administration of a small amount of peanut protein is necessary. Even trace amounts can be sufficient. Skin contact can also cause a mild allergy and rash. Cases have also been reported in which the allergens entered the body by inhalation, such as through airplane ventilation. The allergy is persistent. Only about 20% of affected children outgrow it. In industrialized nations, about 0.5-1% of the population is affected.
Diagnosis
Diagnosis is made on the basis of patient history, clinical symptoms, and with an allergy test (epicutaneous test, detection of antibodies). Double-blind exposure to peanuts is considered the gold standard, although this test is not undisputed in the scientific literature because of the potential risks.
Prevention
Peanuts and foods containing peanuts should be strictly avoided. In practice, however, this is not easy, and accidental ingestion is common. Purified peanut oil is considered safe, but there are also allergenic peanut oils, so allergy sufferers usually avoid it.
Treatment
Patients should carry an emergency allergy kit with a pre-filled epinephrine shot and antihistamines at all times in case of emergency. In many countries, it usually also contains glucocorticoids. It is important to provide good education to the affected person and family members so that the first symptoms are recognized quickly. The injection should be applied when a severe reaction occurs or has occurred previously. Medical help should be sought quickly after application. In medical treatment, acute reactions are treated with oxygen, adrenaline, beta2-sympathomimetics, antihistamines and glucocorticoids, among others. Because of a possible late reaction, patients must be monitored for a sufficiently long time.
