upper respiratory tract infection Broadly speaking, upper respiratory tract infection (URTI) is a collective term for acute inflammation in the nasal cavity, pharynx, or larynx, including primarily acute nasopharyngitis, as well as viral pharyngitis, laryngitis, herpetic pharyngitis, pharyngoconjunctival fever, bacterial pharyngotonsillitis, and similar conditions. Narrowly defined, upper respiratory tract infection, also known as the common cold, is the most common acute respiratory infectious disease, with a high incidence and is mostly self-limiting.

Broadly speaking, upper respiratory tract infection refers to acute inflammation of the nasal cavity, pharynx, or larynx. It includes conditions such as acute nasopharyngitis (common cold), viral pharyngitis, laryngitis, herpetic pharyngitis, pharyngoconjunctival fever, and bacterial pharyngotonsillitis. The common cold, also known as acute nasopharyngitis, is the most prevalent acute respiratory infectious disease, often self-limiting. Upper respiratory tract infections, commonly referred to as "upper respiratory infections," are primarily caused by viruses, with a minority being bacterial in origin. Influenza, caused by the influenza virus, is a seasonal infectious disease that requires attention.

"Common cold" characterized by acute nasopharyngitis.

Upper respiratory tract infections with pharyngitis as the main manifestation include the following:

Acute viral pharyngitis

Acute viral laryngitis

Herpetic pharyngitis

Pharyngoconjunctival fever

Bacterial pharyngotonsillitis

"Common cold" characterized by acute nasopharyngitis: Most commonly caused by rhinoviruses, but can also be caused by coronaviruses, parainfluenza viruses, respiratory syncytial virus, adenoviruses, echoviruses, and coxsackieviruses.

Upper respiratory tract infections with pharyngitis as the main manifestation mainly include:

Acute viral pharyngitis: Primarily caused by influenza viruses and adenoviruses.

Acute viral laryngitis: Often caused by influenza viruses, rhinoviruses, parainfluenza viruses, or adenoviruses.

Herpetic pharyngitis: Mainly caused by coxsackievirus A.

Pharyngoconjunctival fever: Mainly caused by adenoviruses and coxsackieviruses, often occurring in summer and transmitted during swimming.

Pharyngotonsillitis: Mainly caused by Streptococcus pyogenes, but can also be caused by Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus, and others.

Various factors that lead to a decrease in overall or local respiratory defense function can trigger upper respiratory tract infections:

Getting caught in the rain, getting chilled, sudden climate changes, and excessive fatigue.

Anemia, deficiency of vitamins A and D, etc.

Immune deficiency in the elderly, frail individuals, and young children.

Patients with chronic respiratory diseases.

Additionally, factors such as crowded environments, sedentary lifestyles, air pollution, age, smoking, malnutrition, stress, insomnia, etc., are also risk factors for upper respiratory tract infections.

Common Cold

Characterized by inflammation of the nasal and pharyngeal mucosa, including symptoms such as cough, rhinorrhea, sneezing, and nasal congestion.

Early symptoms mainly involve nasal inflammation, with sneezing, nasal congestion, and clear nasal discharge. Initially, there might be discomfort or dryness in the throat, or a scratchy or burning sensation.

After 2-3 days, the discharge becomes thicker, and there may be sore throat or hoarseness. Due to eustachian tube inflammation, hearing loss may occur. Other symptoms may include tearing, dulled sense of taste, difficulty breathing, cough, and occasional production of small amounts of sputum.

Generally, there is no fever or systemic symptoms, or only mild fever. In severe cases, in addition to fever, there may be a sense of fatigue, chills, limb pain, headaches, and loss of appetite, among other systemic symptoms.

Examination by a doctor may reveal congested and edematous nasal mucosa, mild congestion in the throat, and no abnormalities in the chest.

Upper Respiratory Infections with Pharyngitis as the Main Manifestation

Acute viral pharyngitis

Clinically, it mainly presents with throat itching and burning, with cough being rare. Fever and fatigue may be present. Examination by a doctor may reveal significant congestion and edema in the throat, and tender cervical lymph nodes.

Acute viral laryngitis

Clinical presentation includes hoarseness, cough with throat pain, and fever. Examination by a doctor may reveal congestion and edema in the larynx, mild enlargement of local lymph nodes with tenderness, and sometimes wheezing may be heard.

Herpetic pharyngitis

Clinical presentation includes significant throat pain and fever. Examination by a doctor may reveal throat congestion, with grey-white vesicles and shallow ulcers on the soft palate, uvula, pharynx, and tonsils, surrounded by erythema, which later develop into vesicles.

Pharyngoconjunctival fever

Clinical presentation includes fever, sore throat, photophobia, tearing, etc. Examination by a doctor may reveal significant congestion in the throat and conjunctiva. Its characteristic features include fever, pharyngitis, and acute follicular conjunctivitis in one or both eyes.

Pharyngotonsillitis

Clinical presentation includes significant throat pain, chills, and high fever (temperature may reach 39°C or higher). Examination by a doctor may reveal significant congestion in the throat, enlarged and congested tonsils with purulent secretions, tender and enlarged submandibular lymph nodes, and no abnormal findings in the lungs.

If a patient experiences symptoms such as rhinorrhea, nasal congestion, sneezing, and cough, it is likely caused by a virus. If a patient experiences throat pain along with sudden high fever and swollen lymph nodes but without symptoms of the common cold, it may be caused by a bacterial infection. This indicates the need for medical consultation and possibly microbial testing, such as a streptococcal test.

Close contact with patients with upper respiratory tract infections can lead to transmission, so it is important to practice relative isolation.

Develop healthy habits: wash hands frequently, drink plenty of water, maintain nasal hygiene, and avoid touching the mouth, eyes, and nose with dirty hands.

Avoid getting chilled, caught in the rain, and excessive fatigue.

Maintain a balanced diet, adequate sleep, exercise, strengthen the body, and avoid passive smoking.

Elderly and frail individuals should take precautions, such as wearing masks when going out during peak seasons and avoiding crowded public places.

As there are numerous serotypes of viruses that cause the common cold and the viruses mutate frequently, a vaccine for the common cold has not been developed to date. The influenza vaccine is ineffective against the common cold.

For individuals who frequently experience upper respiratory tract infections or those who are elderly or immunocompromised, it may be appropriate to take immune-enhancing agents or receive traditional Chinese medicine treatment as needed.