Upper respiratory tract infection | |
---|---|
Conducting passages | |
Specialty | Infectious disease |
Frequency | (2015) [1] |
Deaths | 3,100 [2] |
An upper respiratory tract infection (URTI) is an illness caused by an acute infection, which involves the upper respiratory tract, including the nose, sinuses, pharynx, larynx or trachea. [3] [4] This commonly includes nasal obstruction, sore throat, tonsillitis, pharyngitis, laryngitis, sinusitis, otitis media, and the common cold. [5] : 28 Most infections are viral in nature, and in other instances, the cause is bacterial. [6] URTIs can also be fungal or helminthic in origin, but these are less common. [7] : 443–445
In 2015, 17.2 billion cases of URTIs are estimated to have occurred. [1] As of 2016, they caused about 3,000 deaths, down from 4,000 in 1990. [8]
In uncomplicated colds, coughing and nasal discharge may persist for 14 days or more even after other symptoms have resolved. [6] Acute URTIs include rhinitis, pharyngitis/tonsillitis, and laryngitis often referred to as a common cold, and their complications: sinusitis, ear infection, and sometimes bronchitis (though bronchi are generally classified as part of the lower respiratory tract.) Symptoms of URTIs commonly include cough, sore throat, runny nose, nasal congestion, headache, low-grade fever, facial pressure, and sneezing. [9]
Symptoms of rhinovirus in children usually begin 1–3 days after exposure. The illness usually lasts 7–10 more days. [6]
Color or consistency changes in mucous discharge to yellow, thick, or green are the natural course of viral URTI and not an indication for antibiotics. [6]
Group A beta-hemolytic streptococcal pharyngitis/tonsillitis (strep throat) typically presents with a sudden onset of sore throat, pain with swallowing, and fever. Strep throat does not usually cause a runny nose, voice changes, or cough.[ citation needed ]
Pain and pressure of the ear caused by a middle-ear infection (otitis media) and the reddening of the eye caused by viral conjunctivitis [10] are often associated with URTIs.
In terms of pathophysiology, rhinovirus infection resembles the immune response. The viruses do not cause damage to the cells of the upper respiratory tract, but rather cause changes in the tight junctions of epithelial cells. This allows the virus to gain access to tissues under the epithelial cells and initiate the innate and adaptive immune responses. [5] : 27
Up to 15% of acute pharyngitis cases may be caused by bacteria, most commonly Streptococcus pyogenes , a group A streptococcus in streptococcal pharyngitis ("strep throat"). [11] Other bacterial causes are Streptococcus pneumoniae , Haemophilus influenzae , Corynebacterium diphtheriae , Bordetella pertussis , and Bacillus anthracis [ citation needed ].
Sexually transmitted infections have emerged as causes of oral and pharyngeal infections. [12]
Symptoms | Allergy | URI (Common Cold) | Influenza (Flu) |
---|---|---|---|
Itchy, watery eyes | Common | Rare (conjunctivitis may occur with adenovirus) | Soreness behind eyes, sometimes conjunctivitis |
Nasal discharge | Common | Common [6] | Common |
Nasal congestion | Common | Common | Sometimes |
Sneezing | Very common | Very common [6] | Sometimes |
Sore throat | Sometimes (post-nasal drip) | Very common [6] | Sometimes |
Cough | Sometimes | Common (mild to moderate, hacking) [6] | Common (dry cough, can be severe) |
Headache | Uncommon | Rare | Common |
Fever | Never | Rare in adults, possible in children [6] | Very common 37.8–38.9 °C (100–102 °F)(or higher in young children), lasting 3–4 days; may have chills |
Malaise | Sometimes | Sometimes | Very common |
Fatigue, weakness | Sometimes | Sometimes | Very common (can last for weeks, extreme exhaustion early in course) |
Muscle pain | Never | Slight [6] | Very common (often severe) |
A URTI may be classified by the area inflamed. Rhinitis affects the nasal mucosa, while rhinosinusitis or sinusitis affects the nose and paranasal sinuses, including frontal, ethmoid, maxillary, and sphenoid sinuses. Nasopharyngitis (rhinopharyngitis or the common cold) affects the nares, pharynx, hypopharynx, uvula, and tonsils generally. Without involving the nose, pharyngitis inflames the pharynx, hypopharynx, uvula, and tonsils. Similarly, epiglottitis (supraglottitis) inflames the superior portion of the larynx and supraglottic area; laryngitis is in the larynx; laryngotracheitis is in the larynx, trachea, and subglottic area; and tracheitis is in the trachea and subglottic area.[ citation needed ]
Vaccination against influenza viruses, adenoviruses, measles, rubella, Streptococcus pneumoniae , Haemophilus influenzae , diphtheria, Bacillus anthracis , and Bordetella pertussis may prevent them from infecting the URT or reduce the severity of the infection.[ citation needed ]
Treatment comprises symptomatic support usually via analgesics for headache, sore throat, and muscle aches. [13] Moderate exercise in sedentary subjects with a naturally acquired URTI probably does not alter the overall severity and duration of the illness. [14] No randomized trials have been conducted to ascertain benefits of increasing fluid intake. [15]
Prescribing antibiotics for laryngitis is not a suggested practice. [16] The antibiotics penicillin V and erythromycin are not effective for treating acute laryngitis. [16] Erythromycin may improve voice disturbances after a week and cough after 2 weeks, but any modest subjective benefit is not greater than the adverse effects, cost, and the risk of bacteria developing resistance to the antibiotics. [16] Health authorities have been strongly encouraging physicians to decrease the prescribing of antibiotics to treat common URTIs because antibiotic usage does not significantly reduce recovery time for these viral illnesses. [16] A 2017 systematic review found three interventions which were probably effective in reducing antibiotic use for acute respiratory infections: C-reactive protein testing, procalcitonin-guided management, and shared decision-making between physicians and patients. [17] The use of narrow-spectrum antibiotics has been shown to be just as effective as broad-spectrum alternatives for children with acute bacterial URTIs, and has a lower risk of side effects in children. [18] Decreased antibiotic usage may also help prevent drug-resistant bacteria. Some have advocated a delayed antibiotic approach to treating URTIs, which seeks to reduce the consumption of antibiotics while attempting to maintain patient satisfaction. A Cochrane review of 11 studies and 3,555 participants explored antibiotics for respiratory tract infections. It compared delaying antibiotic treatment to either starting them immediately or to no antibiotics. Outcomes were mixed depending on the respiratory tract infection; symptoms of acute otitis media and sore throat were modestly improved with immediate antibiotics with minimal difference in complication rate. Antibiotic usage was reduced when antibiotics were only used for ongoing symptoms and maintained patient satisfaction at 86%. [19] In a trial involving 432 children with a URTI, amoxicillin was no more effective than placebo, even for children with more severe symptoms such as fever or shortness of breath. [20] [21]
For sinusitis while at the same time discouraging overuse of antibiotics the CDC recommends:
No good evidence exists for or against the effectiveness of over-the-counter cough medications for reducing coughing in adults or children. [22] Children under 2 years old should not be given any type of cough or cold medicine due to the potential for life-threatening side effects. [23] In addition, according to the American Academy of Pediatrics, the use of cough medicine to relieve cough symptoms should be avoided in children under 4 years old, and the safety is questioned for children under 6 years old. [24]
According to a Cochrane review, a single oral dose of nasal decongestant in the common cold is modestly effective for the short-term relief of congestion in adults; however, data on the use of decongestants in children are insufficient. Therefore, decongestants are not recommended for use in children under 12 years of age with the common cold. [19] Oral decongestants are also contraindicated in patients with hypertension, coronary artery disease, and history of bleeding strokes. [26] [27]
Mucolytics such as acetylcysteine and carbocystine are widely prescribed for upper and lower respiratory tract infection without chronic broncho-pulmonary disease. However, in 2013 a Cochrane review reported their efficacy to be limited. [28] Acetylcysteine is considered to be safe for the children older than 2 years. [28]
Routine supplementation with vitamin C is not justified, as it does not appear to be effective in reducing the incidence of common colds in the general population. [29] The use of vitamin C in the inhibition and treatment of upper respiratory infections has been suggested since the initial isolation of vitamin C in the 1930s. Some evidence exists to indicate that it could be justified in persons exposed to brief periods of severe physical exercise and/or cold environments. [29] Given that vitamin C supplements are inexpensive and safe, people with common colds may consider trying vitamin C supplements to assess whether they are therapeutically beneficial in their case. [29]
Some low-quality evidence indicates the use of nasal irrigation with saline solution may alleviate symptoms in some people. [30] Also, saline nasal sprays can be of benefit.[ citation needed ]
Children typically have two to nine viral respiratory illnesses per year. [6] In 2013, 18.8 billion cases of URTIs were reported. [31] As of 2014, they caused about 3,000 deaths, down from 4,000 in 1990. [8] In the United States, URTIs are the most common infectious illness in the general population, and are the leading reasons for people missing work and school.[ citation needed ]
Weak evidence suggests that probiotics may be better than a placebo treatment or no treatment for preventing upper respiratory tract infections. [32]
Sinusitis, also known as rhinosinusitis, is an inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include thick nasal mucus, a plugged nose, and facial pain.
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity of the condition is variable.
Streptococcal pharyngitis, also known as streptococcal sore throat, is pharyngitis caused by Streptococcus pyogenes, a gram-positive, group A streptococcus. Common symptoms include fever, sore throat, red tonsils, and enlarged lymph nodes in the front of the neck. A headache and nausea or vomiting may also occur. Some develop a sandpaper-like rash which is known as scarlet fever. Symptoms typically begin one to three days after exposure and last seven to ten days.
The common cold or the cold is a viral infectious disease of the upper respiratory tract that primarily affects the respiratory mucosa of the nose, throat, sinuses, and larynx. Signs and symptoms may appear in as little as two days after exposure to the virus. These may include coughing, sore throat, runny nose, sneezing, headache, and fever. People usually recover in seven to ten days, but some symptoms may last up to three weeks. Occasionally, those with other health problems may develop pneumonia.
A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.
Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. The other main type is otitis media with effusion (OME), typically not associated with symptoms, although occasionally a feeling of fullness is described; it is defined as the presence of non-infectious fluid in the middle ear which may persist for weeks or months often after an episode of acute otitis media. Chronic suppurative otitis media (CSOM) is middle ear inflammation that results in a perforated tympanic membrane with discharge from the ear for more than six weeks. It may be a complication of acute otitis media. Pain is rarely present. All three types of otitis media may be associated with hearing loss. If children with hearing loss due to OME do not learn sign language, it may affect their ability to learn.
Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a hoarse voice. Symptoms usually last 3–5 days, but can be longer depending on cause. Complications can include sinusitis and acute otitis media. Pharyngitis is a type of upper respiratory tract infection.
Cold medicines are a group of medications taken individually or in combination as a treatment for the symptoms of the common cold and similar conditions of the upper respiratory tract. The term encompasses a broad array of drugs, including analgesics, antihistamines and decongestants, among many others. It also includes drugs which are marketed as cough suppressants or antitussives, but their effectiveness in reducing cough symptoms is unclear or minimal.
Acute bronchitis, also known as a chest cold, is short-term bronchitis – inflammation of the bronchi of the lungs. The most common symptom is a cough. Other symptoms include coughing up mucus, wheezing, shortness of breath, fever, and chest discomfort. The infection may last from a few to ten days. The cough may persist for several weeks afterward with the total duration of symptoms usually around three weeks. Some have symptoms for up to six weeks.
Sore throat, also known as throat pain, is pain or irritation of the throat. The majority of sore throats are caused by a virus, for which antibiotics are not helpful. A strong association between antibiotic misuse and antibiotic resistance has been shown.
Bronchiolitis is inflammation of the small airways in the lungs. Acute bronchiolitis is due to a viral infection usually affecting children younger than two years of age. Symptoms may include fever, cough, runny nose, wheezing, and breathing problems. More severe cases may be associated with nasal flaring, grunting, or the skin between the ribs pulling in with breathing. If the child has not been able to feed properly, signs of dehydration may be present.
Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a contagious virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. Its name is derived from the large cells known as syncytia that form when infected cells fuse.
Laryngitis is inflammation of the larynx. Symptoms often include a hoarse voice and may include fever, cough, pain in the front of the neck, and trouble swallowing. Typically, these last under two weeks.
Tonsillitis is inflammation of the tonsils in the upper part of the throat. It can be acute or chronic. Acute tonsillitis typically has a rapid onset. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and enlarged lymph nodes around the neck. Complications include peritonsillar abscess (quinsy).
Lower respiratory tract infection (LRTI) is a term often used as a synonym for pneumonia but can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, coughing and fatigue. A routine chest X-ray is not always necessary for people who have symptoms of a lower respiratory tract infection.
Post-nasal drip (PND), also known as upper airway cough syndrome (UACS), occurs when excessive mucus is produced by the nasal mucosa. The excess mucus accumulates in the back of the nose, and eventually in the throat once it drips down the back of the throat. It can be caused by rhinitis, sinusitis, gastroesophageal reflux disease (GERD), or by a disorder of swallowing. Other causes can be allergy, cold, flu, and side effects from medications.
Rhinorrhea, also spelled rhinorrhoea or rhinorrhœa, or informally runny nose is the free discharge of a thin mucus fluid from the nose; it is a common condition. It is a common symptom of allergies or certain viral infections, such as the common cold or COVID-19. It can be a side effect of crying, exposure to cold temperatures, cocaine abuse, or drug withdrawal, such as from methadone or other opioids. Treatment for rhinorrhea may be aimed at reducing symptoms or treating underlying causes. Rhinorrhea usually resolves without intervention, but may require treatment by a doctor if symptoms last more than 10 days or if symptoms are the result of foreign bodies in the nose.
Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bronchioles, alveoli, pleurae, pleural cavity, the nerves and muscles of respiration. Respiratory diseases range from mild and self-limiting, such as the common cold, influenza, and pharyngitis to life-threatening diseases such as bacterial pneumonia, pulmonary embolism, tuberculosis, acute asthma, lung cancer, and severe acute respiratory syndromes, such as COVID-19. Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease.
Respiratory tract infections (RTIs) are infectious diseases involving the lower or upper respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection or a lower respiratory tract infection. Lower respiratory infections, such as pneumonia, tend to be far more severe than upper respiratory infections, such as the common cold.
In clinical guidelines chronic cough is defined as a cough lasting more than 8 weeks in adults and more than 4 weeks in children. there are studies suggest that a chronic cough must persist upwards of three months. The prevalence of chronic cough is about 10% although the prevalence may differ depending on definition and geographic area. Chronic cough is a common symptom in several different respiratory diseases like COPD or pulmonary fibrosis but in non-smokers with a normal chest x-ray chronic cough are often associated with asthma, rhinosinusitis, and gastroesophageal reflux disease or could be idiopathic. Generally, a cough, for example after an upper respiratory tract infection, lasts around one to two weeks; however, chronic cough can persist for an extended period of time, several years in some cases. The current theory about the cause of chronic cough, independent of associated condition, is that it is caused by a hypersensitivity in the cough sensory nerves, called cough hypersensitivity syndrome. There are a number of treatments available, depending on the associated disease but the clinical management of the patients remains a challenge. Risk factors include exposure to cigarette smoke, and exposure to pollution, especially particulates.