Overview
Allergic rhinitis, also known as allergic rhinitis, is a chronic inflammatory disease of the nasal mucosa caused by IgE-mediated release of mediators (mainly histamine) in atopic individuals after exposure to allergens, with the involvement of various immunologically active cells and cytokines, and characterized by nasal itching, sneezing, nasal hypersecretion, and swelling of the nasal mucosa. The disease is often clinically divided into perennial allergic rhinitis and seasonal allergic rhinitis, the latter also known as “hay fever”. Although allergic rhinitis is not a serious disease, it can affect the patient’s daily life, study and work efficiency, and cause a heavy financial burden. It can lead to bronchial asthma, sinusitis, nasal polyps, otitis media, or occur simultaneously with allergic conjunctivitis.
Signs and symptoms
1.The typical symptoms of allergic rhinitis are mainly paroxysmal sneezing with continuous episodes and large amount of watery clear mucus, followed by nasal congestion and nasal itching. Some patients have hyposmia, but it is temporary.
(1) Sneezing: It is a reflex action with paroxysmal episodes, ranging from several to dozens at a time, mostly in the morning, at night or after exposure to allergens.
(2) Clear nasal discharge: it is a large amount of clear water-like nasal discharge, which is a characteristic manifestation of nasal hypersecretion.
(3) Nasal itch: It is a special sensation that occurs locally after the sensory nerve endings of nasal mucosa are stimulated. Seasonal rhinitis may be accompanied by itchy eyes, itchy ears, itchy throat, etc.
(4) Nasal congestion: varying in severity, intermittent or persistent, unilateral, bilateral or alternating on both sides.
(5) Hyposmia: Due to the obvious edema of nasal mucosa, some patients still have hyposmia, mostly temporary, but it can also be persistent.
(6) Headache: Headache may occur in those with combined allergic sinusitis.
The nasal mucosa can be pale, gray or light blue, the inferior turbinates are edematous, and clear or mucus can be seen in the common nasal passage and the bottom of the nasal cavity. If combined with infection, the mucosa is congested, the bilateral inferior turbinates are dark red, and the secretion is mucopurulent or purulent. In cases with a long history, polypoid changes in the middle turbinates, enlarged inferior turbinates or polyps in the middle nasal tract can be seen.
Treatment
1. Avoiding contact with allergens is the most effective way to prevent and treat allergic rhinitis. However, some allergens, especially inhalational allergens, are often difficult to avoid, but they are a necessary part of the treatment strategy.
2, drug therapy In recent years, due to the continuous introduction of efficient, long-acting and safe drugs, drug therapy plays an important role in the treatment of allergic rhinitis, and it is best to combine drugs at first, and then reduce the amount of drugs used after the symptoms are stabilized.
(1) antihistamines: mainly by competing with histamine for histamine receptors on the effector cell membrane to play the role of anti-H1 receptors. Traditional oral antihistamines, such as chlorpheniramine (paracetamol) because of its central inhibitory effect, should be used with caution or not to engage in precision machinery operations and drivers and passengers, and personnel working at height. The new antihistamines, widely used in recent years, non-sedating H1 receptor antagonists such as cetirizine (10mg per time, once a day), loratadine (also known as keratan, Keminergy, 10mg per time, once a day), loratadine citrate (also known as Beixue, Enrette, 10mg per time, once a day), not only to overcome the central inhibitory effect of traditional antihistamines, and anti-H1 receptor effects are significantly enhanced. Antihistamines for nasal spray, such as Lefotene (levocabastine hydrochloride nasal spray) and Elserpine (azelastine hydrochloride nasal spray), have positive efficacy, safety and little side effects.
(2) Mast cell stabilizer: Sodium cromoglycate has the effect of blocking the activation of phosphodiesterase A on the surface of mast cells and preventing the degranulation of mast cells. Spray nasal 4 times a day, 10mg each time, or 2% sodium cromoglycate aqueous solution nasal drops. The main disadvantage is the slow onset of action, need to be used 1 to 2 weeks in advance, and the maintenance time is short.
(3) Decongestants: Nasal drops or oral administration such as 1% ephedrine nasal drops, Daphnin, Ergonan (generic name: phenylephrine bromfenamine capsule, each capsule contains 4mg of bromfenamine maleate and 10mg of epinephrine hydrochloride), etc., can effectively relieve nasal congestion, but if used improperly, can cause drug rhinitis, central excitement and increased blood pressure, etc.
(4) Corticosteroids: with anti-metabolic and anti-inflammatory effects, can significantly reduce various inflammatory reactions and relieve nasal metabolic reactions, including nasal congestion symptoms. Intranasal corticosteroids are the most effective drugs for the treatment of allergic rhinitis, and their efficacy exceeds that of antihistamines, decongestants and sodium cromoglycate, and are increasingly becoming the first-line treatment drugs. It is not only effective in the treatment of perennial and seasonal allergic rhinitis, but has also been shown to prevent recurrence after removal of nasal polyps. Existing intranasal corticosteroid preparations include mometasone furoate nasal spray (endosulfan), budesonide (rhinocort), and fluticasone propionate (co-cortisone). After 1 to 2 weeks of using this type of preparation at the dose used, the disease is evaluated and the dose is adjusted according to the efficacy. The principle of dosing is to use the minimum dose to achieve good efficacy. Local irritation is the most common adverse effect. About 10% of patients have different kinds of nasal irritation such as nasal burning sensation or sneezing after medication, and 2% have bloody nasal discharge, but there is no risk of mucosal morphological changes with long-term medication. Systemic side effects are not a serious problem, but prolonged (many years) use of corticosteroids and overdosing still put patients at risk of subthalamic-pituitary-adrenal axis suppression.
(5) Nasal irrigation: saline irrigation of the nasal cavity, or 2.3% hypertonic saline spraying of the nasal cavity, can effectively treat and prevent allergic rhinitis.
(6) Chinese herbal medicine treatment.
3, immunological treatment Traditional immunotherapy by subcutaneous injection of small doses of antigen and gradually increasing the concentration has been used for nearly 100 years. There are many theories about the mechanism of this therapy, but at present most scholars and allergists mostly favor the theory of specific IgE closed antibody that blocks the binding of allergens to IgE. Although immunotherapy relieves clinical symptoms in 60% to 90% of patients, side effects such as allergic-like reactions occur. At present, the best acceptable degree is sublingual desensitization therapy, in addition, there are subcutaneous injection of desensitization preparations.
4.Treatment to reduce the sensitivity of nasal mucosa such as nasal turbinate freezing, laser, radiofrequency and microwave treatment can reduce the sensitivity of nerve endings and nasal congestion symptoms, but the long-term effect may be poor.