What Is an Upper Respiratory Infection?

Upper respiratory tract infection, referred to as upper sensation, is a general term that includes acute inflammation of the nasal cavity, pharynx, or throat. The broad sense is not a diagnosis of a disease, but a group of diseases, including the common cold, viral pharyngitis, laryngitis, herpes angina, pharyngeal conjunctival fever, and bacterial pharyngo-tonsillitis. The upper sense in the narrow sense, also known as the common cold, is the most common acute respiratory infectious disease, mostly self-limiting, but with a high incidence. Adults occur 2 to 4 times a year, and children have a higher incidence, 6 to 8 times a year. Onset can occur throughout the year, more in winter and spring.

Basic Information

English name

upper respiratory tract infection

Visiting department

Respiratory Medicine

Multiple groups

Patients who are old, young, immunocompromised or have chronic respiratory diseases

Common causes

Cold, sudden weather changes, excessive fatigue, etc. can cause viruses or bacteria that already exist in the upper respiratory tract or invade from the outside to rapidly multiply, thereby inducing the disease

Common symptoms

Mainly nasal symptoms, such as sneezing, stuffy nose, running water-like snot

Causes of upper respiratory infections

70% to 80% of upper respiratory tract infections are caused by viruses. Including rhinovirus, coronavirus, adenovirus, respiratory syncytial virus, ecovirus, coxsackie virus, etc. Another 20% to 30% are caused by bacteria. Bacterial infection can be directly infected or secondary to viral infection. Hemolytic streptococcus is the most common, followed by Haemophilus influenzae, pneumococcus, staphylococcus, and sometimes Gram-negative bacteria.

Various causes that lead to a reduction in the overall defense function of the whole body or the respiratory tract, such as cold, rain, sudden weather changes, excessive fatigue, etc. can cause viruses or bacteria that already exist in the upper respiratory tract or invade from the outside to rapidly multiply, thereby inducing the disease. Old and young are weak, susceptible to patients with weakened immune function or chronic respiratory disease.

Clinical manifestations of upper respiratory tract infection

There are different types of clinical manifestations depending on the cause and extent of the disease:

Common cold

Commonly known as "cold fever", also known as acute rhinitis or upper respiratory tract catarrh, mostly caused by rhinovirus, followed by coronavirus, respiratory syncytial virus, ecovirus, coxsackie virus and so on.

Onset is more rapid, ranging from 1 to 3 days, depending on the virus, enteroviruses are shorter, and adenoviruses and respiratory syncytial viruses are longer. Mainly manifested as nasal symptoms, such as sneezing, nasal congestion, running water-like snot, but also as cough, dry throat, itching or burning sensation, or even post-nasal drip. Symptoms such as sneezing, nasal congestion, and running water-like snot may occur at the same time or several hours after the onset. After 2 to 3 days, the nose becomes thick, often accompanied by sore throat, tearing, decreased taste, poor breathing, and hoarseness. Generally no fever and systemic symptoms, or only low fever, discomfort, mild chills, headache. Physical examination showed congestion, edema, and secretions in the nasal mucosa, and mild congestion in the pharynx.

Hearing loss may occur in patients with eustachian tubeitis. Purulent sputum or severe lower respiratory symptoms suggest concomitant viral infections or secondary bacterial infections other than rhinovirus. 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, enterovirus, and respiratory syncytial virus. The clinical features are itching or burning sensation in the pharynx, rare coughing, and insignificant sore throat. When swallowing pain, streptococcal infections are often indicated. Adenovirus and other infections may have fever and fatigue. Adenoviral pharyngitis can be associated with ocular meningitis. On physical examination, the throat was markedly congested and edema, and the submandibular lymph nodes were enlarged and tender.

(2) Acute viral laryngitis is mostly caused by rhinovirus and adenovirus. Clinical features are hoarseness, difficulty speaking, pain when coughing, and often fever, sore throat, or cough. Physical examination showed edema and congestion in the throat, mild swelling and tenderness of local lymph nodes, and wheezing in the throat.

3. Acute herpetic angina

It is usually caused by Coxsackievirus A and manifests as obvious sore throat and fever. The course of disease is about 1 week, which is more frequent than summer attacks. It is more common in children and occasionally in adults. Physical examination revealed congestion of the pharynx, soft palate, uvula, pharyngeal and tonsil surfaces with off-white herpes and superficial ulcers, with redness around them, and herpes later formed.

4. Pharyngeal conjunctival fever

Mainly caused by adenovirus, coxsackie virus and so on. Clinical manifestations include fever, sore throat, photophobia, and tearing. Physical examination showed significant congestion of the pharynx and conjunctiva. The course of the disease is 4 to 6 days, which often occurs in summer. Children are more common and swimmers are easy to spread.

5. Bacterial pharyngeal-tonsillitis

Mostly caused by hemolytic streptococcus, followed by Haemophilus influenzae, pneumococcus, staphylococcus and so on. Sudden onset, obvious sore throat, chills, and fever (body temperature can reach above 39 ° C). Physical examination showed obvious congestion of the pharynx, enlarged and congested tonsils, yellow purulent discharge on the surface, enlarged and tender submandibular lymph nodes, and no abnormal signs in the lungs.

Upper respiratory tract infection test

Blood routine

During a viral infection, the white blood cell count is usually normal or low, and the proportion of lymphocytes is increased. During a bacterial infection, the white blood cell count is often increased, with neutrophils increased or the nuclear left shift.

2. Etiological examination

Because there are many types of viruses, and the clear type does not significantly help the treatment, generally no clear etiology examination is required. If necessary, the type of virus can be determined by immunofluorescence, enzyme-linked immunosorbent assay, virus isolation and identification, and virus serology. Bacterial culture can determine the type of bacteria and conduct drug sensitivity tests to guide clinical medication.

Upper respiratory tract infection diagnosis

A clinical diagnosis can be made based on medical history, epidemiology, and symptoms and signs of the nasopharynx, combined with peripheral blood and negative chest imaging. In special cases, bacterial culture or virus isolation, or virus serological examination can be used to determine the pathogen.

Differential diagnosis of upper respiratory tract infection

The disease must be distinguished from other diseases that initially show cold-like symptoms:

Allergic rhinitis

It is clinically similar to "cold", with differences including:

(1) Sudden onset of illness, itching of the nasal cavity, frequent sneezing, clear nose like snot, no fever, and less cough;

(2) Mostly caused by allergic factors such as mites, dust, animal fur, low temperature and other stimuli;

(3) Symptoms disappear within a few minutes and within 1 to 2 hours if the allergen is removed;

(4) Physical examination showed pale nasal mucosa and edema;

(5) Nasal secretion smear showed increased eosinophils.

2. Influenza

Acute respiratory infectious diseases caused by influenza viruses are highly contagious and often have a wide range of epidemics. Clinical characteristics:

(1) Sudden onset, severe systemic symptoms, chills, high fever, systemic soreness, and obvious inflammation of the eye and conjunctiva. Some patients have nausea, vomiting, and diarrhea.

(2) The symptoms of the nasopharynx are mild.

(3) The virus is an influenza virus, which can be diagnosed by virus isolation or serology if necessary.

(4) Early application of anti-influenza virus drugs such as amantadine and oseltamivir has significant effects.

(5) It can be prevented by injection of influenza vaccine.

3. Acute infectious diseases

Some acute infectious diseases (such as measles, epidemic hemorrhagic fever, meningococcal meningitis, polio, typhoid fever, typhus typhoid fever) often have upper respiratory symptoms in the early stages of the disease. In the epidemic season or endemic area of these diseases Close observation and necessary laboratory inspections shall be conducted for identification.

(1) Symptoms of measles upper respiratory tract infection are prodromal symptoms. About 90% of patients can see small gray-white spots (Coriolis spots) on the buccal mucosa of the maxillary second molar site 2 to 3 days after the onset. Coriolis spots.

(2) Epidemic hemorrhagic fever The main source of infection is rodents, and the epidemic is regional. May have headache, low back pain, orbital pain (commonly known as triple pain), fever, bleeding and kidney damage are the three main symptoms, typical patients may have fever, hypotension shock, oliguria, polyuria and recovery period5 period. Symptoms of systemic poisoning are mild, mainly catarrhal symptoms in the nasopharynx.

(3) Epidemic cerebrospinal meningitis Some patients have symptoms of sore throat and increased nasopharyngeal secretions at the initial stage, and soon enter the stage of sepsis and meningitis, with chills, high fever, headache, and rash. Meningeal irritation may occur in severe headache at a later stage. The main source of infection is carrier, which is transmitted by droplets.

(4) Poliomyelitis is an acute infectious disease caused by polio virus. Children who have not applied the vaccine are susceptible. Most of the prodromal symptoms are symptomatic, and some of them enter the pre-paralysis stage, with neurological symptoms such as temperature rise, limb pain, hypersensitivity, and paralyzed limbs with asymmetry and flaccid paralysis, which are more common in unilateral lower limbs.

(5) Typhoid fever is the earliest symptom of fever, which may be accompanied by upper symptom symptoms, but often with slow pulses, splenomegaly, or roseola. Typhoid etiology and serology are positive, and the course is long.

(6) typhus typhus is more common in winter and spring, and endemic typhus is more common in summer and autumn. Generally, the onset is rapid, the pulse is fast, and there are obvious headaches. A rash appears on the 5th to 6th days after the onset of illness, with a large number and a bleeding rash. Wai Fei reaction was positive.

Upper respiratory tract infection treatment

Symptomatic treatment

(1) Rest: Those who are seriously ill or old and infirm should rest in bed, avoid smoking and drink plenty of water, and maintain indoor air circulation.

(2) Antipyretic and analgesic If you have fever, headache, muscle soreness and other symptoms, you can choose antipyretic and analgesics, such as compound aspirin, acetaminophen, indomethacin (indomethacin), analgesic tablets, cloth Loven et al. Sore throat can be taken orally with various throat tablets such as lysozyme tablets, throat tablets, or traditional Chinese medicine Liushen pills.

(3) Decongestants For nasal congestion and nasal congestion and edema, pseudoephedrine hydrochloride can be used, and 1% ephedrine nasal drops can also be used.

(4) Antihistamines In the case of colds, nasal mucosa sensitivity is often increased, and sneezing and runny nose are frequent. Antihistamines such as chlorpheniramine maleate or diphenhydramine can be used.

(5) Antitussive agents For those with more obvious cough symptoms, dextromethorphan and pentovirin can be given.

2. Etiology treatment

(1) Antibacterial drugs do not require antibacterial drugs to treat simple viral infections. Penicillin, first-generation cephalosporins, and macrolides can be used as appropriate when there is evidence of bacterial infections such as increased white blood cell counts, pus in the pharynx, and yellow sputum. Or quinolone. It is rarely necessary to select sensitive antibacterial drugs according to the pathogen.

(2) Antiviral drug treatment There are currently no specific antiviral drugs, and abuse of antiviral drugs can cause resistance to cold viruses. Therefore, if there is no fever, the immune function is normal, and patients with onset of disease for more than two days generally do not need to be applied. Patients with immunodeficiency can be routinely used early. Broad-spectrum antiviral drugs ribavirin and oseltamivir have a strong inhibitory effect on respiratory syncytial virus and so on, which can shorten the course of the disease.

3. TCM and Chinese medicine treatment

Traditional Chinese medicine with antipyretic and detoxifying effects can also be selected to help improve symptoms and shorten the course of the disease. Xiao Chaihu Granule and Banlangen Granule are widely used.

Prognosis of upper respiratory infections

The disease is mild, has a short course, and is a self-limiting disease. Most patients have a good prognosis. However, very few elderly, frail, and more basic diseases, especially those with severe chronic lung diseases such as chronic obstructive pulmonary disease (COPD), may have poor prognosis due to serious complications.

Upper respiratory tract infection prevention

1. Avoid incentives

Avoid being exposed to cold, rain, and excessive fatigue; avoid contact with cold patients, and avoid contact of dirty hands with mouth, eyes, and nose. The elderly who are vulnerable and susceptible should pay more attention to protection, and wear masks when epidemic of upper respiratory tract is prevalent, to avoid entering and exiting in public places with many people.

2. Enhance physical fitness

Adhering to moderate and regular outdoor sports to improve the body's immunity and cold tolerance is the main method to prevent this disease.

3. Immunomodulatory drugs and vaccines

For frequent and recurrent occurrence of the disease and elderly patients with low immunity, immune boosters can be applied as appropriate.