Allergies can also be fatal. Do you know how to prevent and treat them?

Author: Wang Changyuan, Chief Physician, Xuanwu Hospital, Capital Medical University

Reviewer: He Jingyu, Chief Physician, Xuanwu Hospital, Capital Medical University

Allergic disease refers to an immediate or delayed immune hypersensitivity disease in systemic tissues or organs caused by inhalation, ingestion, injection or contact of a certain allergen. Common allergic diseases in life include allergic asthma, allergic laryngeal edema, allergic rhinitis, allergic conjunctivitis, urticaria, eczema and anaphylactic shock. Globally, about 400 million people suffer from allergic rhinitis, 300 million people suffer from asthma, and 250 million people have food allergies. Allergic diseases have been listed as one of the six most common chronic diseases by the World Health Organization. Allergic diseases not only affect the quality of life of patients, but severe conditions may also endanger their lives, bringing a heavy economic burden to families and society.

Common inhaled allergens in life include pollen, dust mites, fungi, animal fur and excrement, insect scales and debris, etc. Foods that can cause allergies include: ① aquatic products such as fish, shrimp, and crab; ② peanuts, almonds, pistachios, etc.; ③ eggs, milk, meat, etc.; ④ peaches, mangoes, apples, etc.; ⑤ other foods or drinks and condiments such as alcohol and pepper. Drugs are one of the important causes of allergies. Common drugs include penicillin, aspirin, cephalosporins, and iodides.

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Among common allergic diseases, anaphylactic shock, allergic asthma and acute allergic laryngeal edema can be life-threatening and lead to death of patients if not treated promptly.

1. Clinical manifestations of allergic diseases

Depending on the organs affected by the allergy, patients will show varying degrees of respiratory symptoms, skin symptoms, digestive symptoms and other systemic symptoms. Respiratory symptoms may include nasal congestion, nasal itching, sneezing, throat itching, runny nose and other discomforts. Severe allergies can lead to acute laryngeal edema or asthma, with obvious hoarseness, difficulty breathing, changes in consciousness, sweating, cyanosis and other manifestations; skin symptoms may include edema, papules, macules, erythema, purpura, wheals, pain and itching symptoms, etc.; digestive symptoms include abdominal pain, diarrhea, nausea and vomiting and other discomfort symptoms. In severe cases of allergies, anaphylactic shock may occur, and patients may experience symptoms such as fainting, coma, convulsions, and a drop in blood pressure. They should call the emergency number immediately and go to the hospital for treatment.

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Although anaphylactic shock, allergic asthma and acute allergic laryngeal edema are dangerous and have a high mortality rate, they can be avoided if effectively prevented and treated in time. Let's learn about the prevention and treatment of allergic diseases.

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2. Prevention of allergic diseases

Allergic diseases are the result of the combined effects of genetic and environmental factors. Patients with genetic factors cannot make their own choices, but good control of the environment in which patients live and isolating or reducing allergens in the environment can reduce the occurrence of allergic diseases.

Common inhaled indoor allergens include dust mites, animal fur, fungi and cockroaches, while outdoor allergens include pollen from trees, grasses and weeds and outdoor fungi. Dust mites are the main indoor allergens, and carpets, bedding, sofas, mattresses and other places are the most likely to breed dust mites. It is difficult to completely eliminate dust mites, but measures such as lowering indoor relative humidity, using anti-mite household products, and regular cleaning can reduce the number of indoor dust mites and reduce allergen exposure. People who are allergic to animal fur should try not to keep pets and try to avoid contact with pets. Dark, damp, and poorly ventilated basements are ideal places for indoor fungi to breed. Therefore, in life, attention should be paid to ventilation, lowering humidity, and regularly cleaning household facilities to prevent fungal growth. Cockroaches are common indoor allergens. The body, eggs, and feces of cockroaches are all allergens. The living place should block the way for cockroaches to enter the room, and insecticides should be placed to eliminate cockroaches. At the same time, attention should be paid to the hygiene of the living place and reduce food residues.

Outdoor allergens cannot often be effectively avoided. For those who are allergic to pollen, staying indoors as much as possible during the pollen season, closing doors and windows, and reducing going out are effective means of preventing allergies. Avoiding contact with humid environments that breed mold can prevent allergic diseases caused by mold. In addition, if economic conditions allow, long-distance migration or relocation is also an effective measure to avoid contact with outdoor allergens.

Once a food allergy is diagnosed, avoiding eating allergenic foods is the best preventive method, which can reduce the occurrence of allergic reactions, but may have adverse effects on the patient's growth, development and nutritional status. In some cases, it is impossible for patients with food allergies to completely avoid certain types of food. With age, patients with allergies to milk and soy will have some relief, while allergies to peanuts, nuts and seafood will persist. At the same time, the structure of allergens will change during food processing or cooking, and the allergenicity will decrease. For example, some patients are allergic to fresh milk or eggs, but can eat baked milk or eggs. Therefore, when it is completely impossible to avoid eating a certain type of food that may be allergic, you should choose the appropriate cooking method to eat allergenic foods under the guidance of medical professionals, after comprehensively considering your personal conditions and risk factors.

3. Treatment of allergic diseases

The treatment of allergic diseases is a long-term management process. Allergen vaccine desensitization therapy is one of the methods for treating allergic diseases, but antiallergic drugs are the main means of common treatment of allergic diseases and can effectively control symptoms. Commonly used antiallergic drugs include glucocorticoids, antihistamines, leukotriene receptor antagonists, anticholinergics, etc. Allergic skin diseases can be treated with topical glucocorticoid preparations, phosphodiesterase inhibitors, etc. Allergic conjunctivitis can be treated with drugs such as eye drops or eye ointments.

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If the patient has acute allergic laryngeal edema or anaphylactic shock, he should call 120 immediately, explain the condition in detail to the emergency center dispatcher, stay calm and keep the phone open, and give oxygen if conditions permit. After the medical staff arrives, they will give treatment such as epinephrine and dexamethasone according to the condition. If the treatment does not relieve the symptoms or the airway obstruction is severe, first aid measures such as cricothyroid membrane puncture should be performed as soon as possible to save lives.

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References

[1] Han Peng, Yin Ju, Gao Qi, et al. Interpretation of the 2022 Food Allergy Management Guidelines of the Global Allergy and Asthma European Network[J]. Chinese Journal of Practical Pediatrics, 2023, 38(6): 421-426.

[2] Beijing Medical Association Allergy and Allergy Branch. Expert consensus on diagnosis, treatment and prevention of allergic diseases (I) [J]. Chinese Journal of Preventive Medicine, 2022, 56(10): 1387-1394.