Acute upper respiratory tract infection

Introduction to acute upper respiratory infection Acute upper respiratory tract infection is a general term for acute inflammation from the nasal cavity to the larynx and is the most common infectious disease. About 90% are caused by viruses, and bacterial infections are often followed by viral infections. The disease can occur in all seasons and at any age, and spreads through droplets, mists, or contaminated utensils containing viruses. Often when the body's resistance is reduced, such as cold, fatigue, rain, etc., viruses or (and) bacteria that have existed or are invaded by the outside world, rapidly grow and multiply, leading to infection. The disease has a good prognosis and is self-limiting. It usually heals in 5-7 days. Often secondary to bronchitis, pneumonia, paranasal sinusitis, a small number of people can be complicated by acute myocarditis, nephritis, rheumatic fever and so on. basic knowledge The proportion of illness: 90% Susceptible people: no special people Mode of infection: non-infectious Complications: sinusitis otitis media acute tracheal-bronchitis rheumatism glomerulonephritis myocarditis

Causes of acute upper respiratory tract infection

Direct factor (80%):

About 70%-80% of acute upper respiratory tract infections are caused by viruses. There are mainly influenza viruses (A, B, C), parainfluenza viruses, respiratory syncytial virus, adenovirus, rhinovirus, echovirus, coxsackie virus, measles virus, rubella virus. Bacterial infection can occur directly or after viral infection, with hemolytic streptococcus being more common, followed by Haemophilus influenzae, pneumococcus and staphylococcus. Occasionally Gram-negative bacilli. The main manifestations of infection are rhinitis, pharyngitis or tonsillitis.

Systemic factors (20%):

When there are induced factors such as cold, rain, excessive fatigue, etc., the systemic or respiratory local defense function is reduced, the virus or bacteria that have existed in the upper respiratory tract or invaded from the outside can rapidly multiply, causing the disease, especially the weak young and old. Or chronic respiratory diseases such as paranasal sinusitis, tonsillitis, more susceptible to rickets.

Acute upper respiratory infection prevention

The disease can occur throughout the year, often in winter and spring, and can be spread by droplets containing viruses or contaminated utensils. Most of them are sporadic, but they are often prevalent in climate change. Due to the large number of viruses, the human body has weak and short-lived immunity against various viruses, and there is no cross-immunization. At the same time, there are virus carriers in healthy people, so one person can have multiple diseases within one year.

Enhancing the body's own disease resistance is the best way to prevent acute upper respiratory infections. Such as adhering to regular and appropriate physical exercise, adhering to the cold water bath, improve the body's ability to prevent disease and adapt to the cold. Do a good job in cold protection to avoid the cause of the disease. Life is regular, avoiding overwork, especially at night. Pay attention to the isolation of respiratory patients, prevent cross-infection, etc.

Acute upper respiratory tract infection Complications sinusitis otitis media acute tracheal-bronchitis rheumatism glomerulonephritis myocarditis

Can be complicated by acute sinusitis, otitis media, tracheal-bronchitis. Some patients may be secondary to rheumatism, glomerulonephritis, myocarditis and other diseases.

Symptoms of acute upper respiratory tract infections Common symptoms Appetite loss, sore throat and pharyngeal burning, throat congestion, fever, chills, runny nose, hoarseness, nasal distraction, submandibular lymph nodes, swelling, tenderness

Depending on the cause, clinical manifestations can be of different types:

First, the common cold (common cold)

Commonly known as "cold", also known as acute rhinitis or upper respiratory catarrh, with nasopharynx catarrhal symptoms as the main performance. Adults are mostly caused by rhinoviruses, followed by parainfluenza viruses, respiratory syncytial virus, echovirus, and Coxsackie virus. The onset is more urgent. In the early stage, there is dry throat, itchy itch or burning sensation. At the same time or several hours after the onset, there may be sneezing, nasal congestion, and clear watery nose, which will thicken after 2-3 days. May be associated with sore throat, sometimes due to eustachian tube inflammation, hearing loss, tearing, slow taste, poor breathing, hoarseness, a small amount of cough. Generally no fever and systemic symptoms, or only low fever, discomfort, mild chills and headaches. Examination revealed nasal congestion, edema, secretions, and mild congestion of the pharynx. If there is no complication, it usually recovers after 5-7d.

Second, viral pharyngitis, laryngitis and bronchitis

According to the inflammatory reaction caused by the virus on the anatomical parts of the upper and lower respiratory tract infections, the clinical manifestations are pharyngitis, laryngitis and bronchitis.

Acute viral pharyngitis is caused by rhinovirus, adenovirus, influenza virus, parainfluenza virus, enterovirus, respiratory syncytial virus and the like. The clinical features are itchy and burning sensation in the pharynx, and the pain is not persistent and does not stand out. When there is swallow pain, it is often suggested to have streptococcal infection. Cough is rare. Influenza and adenovirus infections can have fever and fatigue. Physical examination of the pharynx was marked by congestion and edema. The submandibular lymph nodes are swollen and tender. Adenovirus pharyngitis can be associated with ocular colitis.

Acute viral laryngitis is caused by rhinovirus, influenza A, parainfluenza and adenovirus. The clinical features are hoarseness, difficulty in speech, pain during coughing, often fever, pharyngitis or cough. Physical examination shows laryngeal edema, congestion, mild lymphadenopathy and tenderness of the local lymph nodes, and can be heard and wheezing.

Acute viral bronchitis is caused by respiratory syncytial virus, influenza virus, coronavirus, parainfluenza virus, rhinovirus, adenovirus and the like. The clinical manifestations are cough, no sputum or sputum mucus, accompanied by fever and fatigue. Other symptoms often include hoarseness and non-pleural subpleural pain. It can be smelled dry or wet. X-ray films showed increased and increased vascular shadows, but no lung infiltration shadows. Influenza or coronavirus Acute bronchitis often occurs in acute attacks of chronic bronchitis.

Third, herpes angina

Often caused by coxsackievirus A, manifested as obvious sore throat, fever, and the course of disease is about one week. Examination showed visible pharyngeal congestion, soft palate, sag, pharyngeal and tonsil surface with grayish white herpes and superficial ulcers, surrounded by redness. More than in summer, more common children, occasionally in adults.

Fourth, pharyngeal conjunctival fever

Mainly caused by adenovirus, Coxsackie virus, etc. Clinical manifestations of fever, sore throat, photophobia, tearing, pharyngeal and combined membranes were significantly congested. The course of disease is 4-6 days, which often occurs in summer and spreads during swimming. More common in children.

5. Bacterial pharyngeal-tocalitis

Mostly caused by hemolytic streptococcus, followed by Haemophilus influenzae, pneumococcus, staphylococcus and the like. Acute onset, obvious sore throat, chills, fever, body temperature can reach above 39 °C. Examination showed obvious hyperemia of the pharynx, tonsil enlargement, hyperemia, yellow spotted exudate on the surface, enlarged submandibular lymph nodes, tenderness, and no abnormal signs in the lungs.

Examination of acute upper respiratory tract infection

Leukocytes are low and early neutrophils are slightly elevated. The total number of white blood cells and neutrophils in the combined bacterial infection can be increased.

First, the blood

For viral infections, the white blood cell count is normal or low, and the proportion of lymphocytes is elevated. Bacterial infections have white blood cell counts and neutrophil enlargement and nuclear left shift.

Second, the determination of virus and virus antigen

Immunofluorescence, enzyme-linked immunosorbent assay, serological diagnostics, and virus isolation and identification can be used as needed to determine the type of virus and distinguish between viral and bacterial infections. Bacterial culture determines the type of bacteria and drug susceptibility test.

Diagnosis and diagnosis of acute upper respiratory tract infection

diagnosis

According to the history, prevalence, symptoms and signs of nasopharynx inflammation, combined with peripheral blood and chest X-ray examination can make a clinical diagnosis. Bacterial culture and virus isolation, or virus serology, immunofluorescence, enzyme-linked immunosorbent assay, hemagglutination inhibition test, etc., can determine the cause of diagnosis.

Diagnose based on

1. Different degrees of fever.

2. Sore throat discomfort, nasal congestion, runny nose, cough, may be accompanied by loss of appetite, fatigue, body aches.

3. The nose, throat and throat are obviously congested and edematous.

4. Exclude other acute infectious diseases.

Differential diagnosis

The disease needs to be identified with the following diseases;

First, allergic rhinitis

Clinically, it is very similar to "cold". The different patients have acute onset, itchy nose, frequent sneezing, and clear watery nose. The attack is related to the environment or temperature change. Sometimes abnormal smell can also occur. After several minutes to 1-2h. get well. Examination: pale nasal mucosa, edema, and smears of nasal secretions showed eosinophilia.

Second, influenza

Often there is a clear popularity. The onset is urgent, the systemic symptoms are heavier, high fever, body aches, and conjunctival inflammation are obvious, but the symptoms of the nasopharynx are mild. Smear specimens of mucosal epithelial cells in the nasal wash of the patient were stained with fluorescently labeled influenza virus immune serum and examined under a fluorescent microscope to facilitate early diagnosis, or virus isolation or serological diagnosis.

Third, acute infectious disease prodromal symptoms

For example, measles, poliomyelitis, encephalitis, etc. often have upper respiratory symptoms in the early stages of the disease, and should be closely observed in the epidemic season or epidemic areas of these diseases, and necessary laboratory tests should be carried out to distinguish them.

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