Upper respiratory tract infections (URI or URTI) are the illnesses caused by an acute infection which involves the upper respiratory tract: nose, sinuses, pharynx or larynx. This commonly includes: tonsillitis, pharyngitis, laryngitis, sinusitis, otitis media, and the common cold.
The upper respiratory tract includes the sinuses, nasal passages, pharynx, and larynx. These structures direct the air we breath from the outside to the trachea and eventually to the lungs for respiration to take place.
An upper respiratory tract infection, or upper respiratory infection, is an infectious process of any of the components of the upper airway.
Infection of the specific areas of the upper respiratory tract can be named specifically. Examples of these may include rhinitis (inflammation of the nasal cavity), sinus infection (sinusitis or rhinosinusitis) - inflammation of the sinuses located around the nose, common cold (nasopharyngitis) - inflammation of the nares, pharynx, hypopharynx, uvula, and tonsils, pharyngitis (inflammation of the pharynx, uvula, and tonsils), epiglottitis (inflammation of the upper portion of the larynx or the epiglottis), laryngitis(inflammation of the larynx), laryngotracheitis (inflammation of the larynx and the trachea), and tracheitis (inflammation of the trachea).
Upper respiratory infections are one of the most frequent causes of doctors visits with varying symptoms ranging from runny nose, sore throat, cough, to breathing difficulty, and lethargy. In the United States, upper respiratory infections are the most common illness leading to missing school or work.
Although upper respiratory infections can happen at any time, they are most common in the fall and winter months, from September until March. This may be explained because these are the usual school months when children and adolescents spend a lot of time in groups and inside closed doors. Furthermore, many viruses of upper respiratory infection thrive in the low humidity of the winter.
Generally, the symptoms of upper respiratory infection result from the toxins released by the pathogens as well as the inflammatory response mounted by the immune system to fight the infection.
Common symptoms of upper respiratory infection generally include:
- nasal congestion,
- runny nose (rhinorrhea),
- nasal discharge (may change from clear to white to green)
- nasal breathing,
- sore or scratchy throat,
- painful swallowing (odynophagia),
- cough (from laryngeal swelling and post nasal drip),
- fever (more common in children).
Other less common symptoms may include foul breath, poor smelling sensation (hyposmia), headache, shortness of breath, sinus pain, itchy andwatery eye (conjunctivitis), nausea, vomiting, diarrhea, and body aches.
The symptoms of upper respiratory infection usually last between 3-14 days; if symptoms last longer than 14 days, an alternative diagnosis can be considered such as, sinusitis, allergy, pneumonia, or bronchitis.
Bacterial pharyngitis (strep throat due to group A streptococcus) may be considered if symptoms continue to worsen after the first week in the absence of runny nose, cough, or conjunctivitis. Prompt testing and initiation of appropriate antibiotics is important due to the risk of developing rheumatic fever, especially in children.
Epiglottitis is an upper respiratory infection in children that may have a more sudden onset of sore throat, feeling of a lump in the throat, muffled voice, dry cough, very painful swallowing, and drooling.
Upper respiratory infections in the lower part of the upper respiratory tract, such as, laryngotracheitis, are more commonly featured with dry cough and hoarseness or loss of voice. Barking or whooping cough, gagging, rib pain (from severe cough) are other presenting features.
People "catch" colds when they come into contact with airborne viruses. Most often, the virus spreads from person to person in respiratory droplets from sneezing or coughing. Transmission of viruses can also spread due to poor hand washing techniques as the virus can be passed from person to person by coming in contact with respiratory droplets from an infected person with a handshake, touching the nose, eyes, or mouth after coming in contact with the virus.
Some viruses can live on surfaces such as sink faucets, door and drawer handles, table surfaces, pens, and computer keyboards for up to two hours.
People should understand that upper respiratory infections are contagious and are spread from person to person. Individuals are infected with the virus before symptoms arise and are therefore potentially contagious even before they know they are ill.
Thus, hygienic measures such as covering sneezes and coughs, and regular hand washing should be a routine habit practiced by everyone even when not ill.
Rhinovirus (rhino from the Greek word for nose) and coronavirus are the two most common viruses causing upper respiratory infections. Other viruses including parainfluenza virus, respiratory syncytial virus, and adenovirus can cause colds but may also cause pneumonia, especially in infants and children.
Most cases of upper respiratory infection are caused by viruses and therefore, require no specific treatment and are self-limited. People with upper respiratory infections typically diagnose themselves and treat their symptoms at home without requiring doctor's visit or prescription medications.
Rest is an important step in treating upper respiratory infections. Usual activities, such as, working and light exercising may be continued as much as tolerated.
Increased intake of oral fluids are also generally advised to keep up with the fluid loss from runny nose, fevers, and poor appetite associated with upper respiratory infections.
Treatment of the symptoms of upper respiratory infection are usually continued until the infection has resolved.
Some of the most common upper respiratory infection or cold medications used to treat these symptoms are the following:
Acetaminophen (Tylenol) can be used to reduce fever and body aches.
Nonsteroidal antiinflammatory drugs such as ibuprofen (Motrin, Advil) can be used for body aches and fever.
Antihistamines such as diphenhydramine (Benadryl) are helpful in decreasing nasal secretions and congestions.
Nasal ipratropium (topical) can be used to diminish nasal secretions.
Cough medications (antitussives) can be used to reduce cough. Many cough medications are commercially available such as dextromethorphan, guaifenesin (Robitussin), and codeine all have shown benefits in reducing cough in upper respiratory infections.
Honey can be used in reducing cough.
Steroids such as (dexamethasone (Decadron) and prednisone orally (and nasally) are sometimes used reduce inflammation of the airway passage and decrease swelling and congestion.
Decongestants such as pseudoephedrine (Sudafed) Actifed oral, phenylephrine (Neo-synephrine nasal) can be used to reduce nasal congestion (generally not recommended in children less than 2 years of age and not recommended for individuals with high blood pressure).
Oxymetazoline (Afrin) nasal solution is a decongestant, but should only be used for short-term.
Combination medications containing many of these components are also widely available over the counter.
Some cough and cold medicines can cause excessive drowsiness need to be used with caution in children younger than 4 years of age and the elderly.
Antibiotics are sometimes used to treat upper respiratory infections if a bacterial infection is suspected or diagnosed. These conditions may include strep throat, bacterial sinusitis, or epiglottitis. Antivirals may occasionally be recommended by doctors in patients who are immunocompromised (poor immune system). The treating doctor can determine which antibiotic would be the best option for a particular infection.
Because antibiotics are associated with many side effects and can promote bacterial resistance and secondary infections, they need to be used very cautiously and only under the direction of a treating physician.
Inhaled epinephrine is sometimes used in children with severe spasm of the airways (bronchospasm) and in croup to reduce spasm.
Rarely, surgical procedures may be necessary in cases of complicated sinus infections, compromised airway with difficulty breathing, formation of abscesses behind the throat, or abscess formation of the tonsils (peritonsillar abscess).