Introduction:
70%~80% of acute upper respiratory tract infections are caused by viruses. Including rhinovirus, coronavirus, adenovirus, influenza and parainfluenza viruses, respiratory syncytial virus, echovirus, coxsackievirus, etc. Another 20%~30% of the upper sensation is caused by bacteria. Bacterial infections can be directly infected or secondary to viral infection, with hemolytic streptococcus being the most common, followed by Haemophiles influenzae, pneumococcus, staphylococcus, etc., and occasionally gram-negative bacteria.
Various causes that lead to the reduction of local defense function of the whole body or respiratory tract, such as cold, rain, sudden climate changes, excessive fatigue, can make the virus or bacteria that already exist in the upper respiratory tract or invade from the outside rapidly multiply, thereby inducing the disease. Patients who are frail in old and young, immunocompromised or have chronic respiratory diseases are susceptible.
Clinical manifest
Depending on the cause and extent of the lesion, clinical manifestations can be of different types:
1. The common cold
Commonly known as "cold", also known as acute rhinitis or upper respiratory tract catarrhal, mostly caused by rhinovirus, followed by coronavirus, parainfluenza virus, respiratory syncytial virus, echovirus, coxsackievirus and so on.
The onset is more acute, the incubation period varies from 1~3 days, depending on the virus, enterovirus is shorter, adenovirus, respiratory syncytial virus and so on are longer. Mainly manifested as nasal symptoms, such as sneezing, nasal congestion, watery nasal discharge, can also be manifested as cough, dry throat, itchy throat or burning sensation, and even postnasal drip sensation. At the same time or a few hours after the onset, there may be symptoms such as sneezing, nasal congestion, and watery nasal discharge. After 2~3 days, the nasal discharge becomes thicker, often accompanied by sore throat, tearing, loss of taste, poor breathing, hoarseness, etc. There is usually no fever and constitutional symptoms, or only low-grade fever, malaise, mild chills, and headache. Physical examination showed nasal mucosal hyperemia, edema, discharge, and mild pharyngeal hyperemia.
Symptoms such as hearing loss may occur when complicated by eustachian tubesitis. Purulent sputum or severe lower respiratory tract symptoms suggest a viral infection other than rhinovirus or secondary bacterial infection. If there are no complications, it can be cured in 5~7 days.
2. Acute viral pharyngitis or laryngitis
(1) Acute viral pharyngitis is mostly caused by rhinovirus, adenovirus, influenza virus, parainfluenza virus, respiratory syncytial virus, etc. Clinical features are itching or burning sensation in the pharynx, uncommon cough, and inconspicuous sore throat. When swallowing is painful, it often indicates streptococcal infection. Influenza virus and adenovirus infection may present with fever and fatigue. Adenoviral pharyngitis may be accompanied by conjugitis of the eye. Physical examination of the pharynx is marked with hyperemia and edema, and submandibular lymph nodes are swollen and tender.
(2) Acute viral laryngitis is mostly caused by rhinovirus, influenza A virus, parainfluenza virus and adenovirus. Clinical features are hoarseness, difficulty speaking, pain in cough, and often fever, sore throat, or cough. Physical examination reveals laryngeal edema, hyperemia, mild swelling and tenderness of regional lymph nodes, and laryngeal stridor.
3. Acute herpangina
Often caused by coxsackievirus A, manifested as obvious sore throat and fever, the course of the disease is about 1 week, more than summer attacks, more common in children, occasionally in adults. Physical examination showed pharyngeal hyperemia, gray-white herpes and superficial ulcers on the surface of the soft palate, uvula, pharynx and tonsils, and a red halo around it, and later herpes.
4. Pharyngeal conjunctival fever
Mainly caused by adenovirus, coxsackievirus, etc. Clinical manifestations include fever, sore throat, photophobia, and lacrimation, and physical examination shows obvious hyperemia of the pharynx and conjugated membrane. The course of the disease is 4~6 days, often occurs in summer, children are more common, swimmers are easy to transmit.
If left untreated, upper respiratory tract infection can spread to other organs and cause corresponding symptoms, and systemic symptoms will be aggravated. Common complications include sinusitis, otitis media, conjuntos, cervical lymphadenitis, and posterior pharyngeal (or lateral) wall abscesses. Complicated by acute otitis media, how high fever does not subside, due to ear pain crying and restlessness, shaking the head, scratching the ears, early tympanic membrane congestion, swelling, later perforation and outflow of serous or pus, untimely treatment can affect hearing. In the case of pharyngeal wall abscess, symptoms such as refusal to eat, dysphagia, slurred speech, head tilted back, mouth breathing and other symptoms can be seen, and the examination can show pharyngeal hyperemia and swelling, and the pharyngeal wall is semicircular protrusion, pushing the soft palate and the ipsilateral pharyngeal palatine arch forward. Young and frail children, upper respiratory tract infections tend to develop downward, causing bronchitis and pneumonia. When complicated by mesenteric lymphadenitis, there is periumbilical paroxysmal abdominal pain without fixed tender points and muscle tension. A small number of bacterial infections can cause systemic and other complications in frail children, such as sepsis, meningitis, and nephritis. When children with streptococcal infections cause upper respiratory tract infections, they are often complicated by allergic diseases such as acute glomerulonephritis and rheumatic fever.
First, blood routine viral infection, the white blood cell count is normal or low, and the proportion of lymphocytes is increased; In bacterial infection, the white blood cell count is often increased, with neutrophilia or left-shifted nucleus.
Second, etiological examination Because there are many types of viruses, and a clear type is not obviously helpful for treatment, there is generally no need to clarify the etiology examination. If necessary, immunofluorescence, enzyme-linked immunosorbent, virus isolation and identification, virus serological examination, etc. can be used to determine the virus type. Bacterial culture can determine the type of bacteria and do drug susceptibility tests to guide clinical use.
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