Allergic rhinitis in children, also known as allergic rhinitis in children, is a non-infectious inflammatory disease of the nasal mucosa mediated mainly by specific IgE in susceptible children after exposure to allergens, with a prevalence of 10%-40% in the population, accounting for about 40% of all rhinitis and continuing to increase as a global health problem.
Etiology
Genetic factors Patients with allergic rhinitis have an atopic constitution with a higher than normal ability to produce IgE antibodies, and most have a family history of asthma, urticaria or drug allergy aggregation.
Allergen exposure Allergens are antigens that induce specific IgE antibodies and react with them. They are mostly derived from animals, plants, insects, fungi or occupational substances. Their composition is proteins or glycoproteins and very rarely polysaccharides. Allergens are mainly divided into inhalant allergens and food allergens. Inhalant allergens are the main cause of allergic rhinitis and include house dust mites, dust mites, pollen, animal dander, fungi, cockroaches, etc. For infants, most food allergens are caused by milk and soy. For adults, common food allergens include: peanuts, nuts, fish, eggs, milk, soy, apples, pears, etc.
Classification
1, according to the duration of symptoms are divided into two categories: intermittent allergic rhinitis and persistent allergic rhinitis.
(1) Intermittent: symptom expression <4d/week, or <4 consecutive weeks.
(2) Persistent: symptom expression ≥ 4d/week and ≥ 4 consecutive weeks.
2. The classification of the disease is based on the severity of the symptoms and the impact on the quality of life: mild and moderate-severe.
(1) Mild: symptoms are mild and have no significant impact on learning, cultural and physical activities and sleep.
(2) Moderate-severe: symptoms are obvious and affect learning, cultural and sports activities and sleep.
Clinical manifestations
Clear watery mucus, nasal itching, nasal congestion, sneezing and other symptoms appear more than 2 (including 2), and the symptoms last or accumulate for about 1h or more per day. Itchy eyes, conjunctival congestion and other eye symptoms may be present. Children with severe symptoms may have the so-called “allergic salute”, i.e. rubbing the nose upward with the palm of the hand or fingers in order to relieve nasal itching and make the nasal passages clear.
Physical examination: pale and edematous nasal mucosa and watery nasal discharge are common. Children with severe symptoms may present with.
1. allergic dark circles: dark shadows on the lower eyelids due to swelling of the lower eyelids.
2. allergic folds: transverse wrinkles on the skin surface of the nose due to frequent upward rubbing of the nasal tip.
Laboratory tests
Skin prick test is performed at least 7 d after discontinuation of antihistamines. Using a standardized allergen reagent, the skin is punctured on the palmar side of the forearm and the results are observed for 20 min. Positive and negative controls should be performed for each test, with histamine used as the positive control and allergenic lysis medium used as the negative control. The results should be determined according to the corresponding standardized allergen reagent instructions. The serum-specific IgE test is suitable for any age and is one of the important laboratory indicators for the diagnosis of allergic rhinitis in children.
Diagnosis
The diagnosis of allergic rhinitis in children is confirmed by the presence of the above clinical manifestations (symptoms, signs) and a positive result of either of the 2 skin prick tests or the serum specific IgE test.
Treatment
Drug treatment
Antihistamines are recommended for oral or nasal use as second-generation or newer H1 antihistamines, which are effective in relieving symptoms such as nasal itching, sneezing and runny nose and are the treatment of choice for mild intermittent and mild persistent allergic rhinitis. Oral H1 antihistamines are also effective in relieving eye symptoms. The course of treatment is usually not less than 2 weeks. Syrup preparations are recommended for under 5 years of age, and oral tablets can be given above 5 years of age in doses calculated according to age and body weight.
Nasal glucocorticosteroids are the drug of choice for the treatment of moderate-severe persistent allergic rhinitis, but can also be applied to mild patients, and are useful for improving symptoms such as nasal congestion, runny nose, sneezing and nasal itching for at least 4 weeks. They should be used in children of different ages as recommended in the instructions for each type of drug.
Antileukotrienes are important drugs for the treatment of moderate-to-severe allergic rhinitis, especially for children with lower respiratory symptoms (e.g., combined with airway hyperresponsiveness, bronchial asthma, etc.), and are often used in combination with nasal sprays or inhaled glucocorticoids.
Chromones are effective in relieving nasal symptoms but have a slower onset of action. They can also be used as preventive medication before the pollen dispersal season for people who are allergic to pollen. Eye drops are effective in relieving eye symptoms.
Decongestants can be applied at low concentrations when nasal congestion is severe, for no more than 7 d. Hydroxymetazoline and Serozoline preparations for children are recommended, and preparations containing naphazoline are prohibited.
Nasal saline rinses are an adjunctive treatment to improve symptoms, cleanse the nasal cavity, and restore nasal mucosal function; saline or 1%-2% hypertonic saline is recommended.
Immunotherapy
Methods: Allergen-specific immunotherapy is commonly administered by subcutaneous injection and sublingual administration. The course of treatment is divided into a dose accrual phase and a dose maintenance phase, with a total course of not less than 2 years. Standardized allergen vaccines should be used. It is the only treatment modality that has the potential to alter the natural course of the disease through immunomodulatory mechanisms.
Indications: allergic rhinitis over 5 years of age, refractory to conventional drug therapy, caused primarily by dust mite allergy. The diagnosis is clear, the number of combined other allergens is low (1-2), and the parents of the child understand the risks and limitations of the treatment.
Adverse reactions to immunotherapy can be divided into local and systemic reactions. Systemic reactions are classified as rapid systemic reactions (occurring within 30 min after injection) and delayed systemic reactions (occurring after 30 min after injection).
Prevention
1. Avoid contact with known allergens, such as pets, feathers, pollen, etc.
2, do a good job of indoor environmental control, such as frequent ventilation, reduce the city dust, bedding and clothing to keep dry, do not use carpets, etc.
3, usually exercise to enhance physical fitness and prevent cold.
4.For children with seasonal onset, parents need to be prompted to use preventive medicine 2-3 weeks before the season.