Acute viral nasopharyngitis (common cold)

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Acute viral nasopharyngitis is a highly contagious viral infectious disease of the upper respiratory system primarily caused by rhinovirus and less commonly caused by picornaviruses or coronaviruses. Common symptoms are sore throat, runny nose, nasal congestion, sneezing, and cough sometimes accompanied by muscle aches, fatigue, malaise, headache, muscle weakness, or loss of appetite. Fever and extreme exhaustion are more common in influenza. The symptoms of a cold usually resolve after about one week, but can last up to 14 days. Symptoms may be more severe in infants and young children. Although the disease is generally mild and self-limiting, patients with the common cold often seek professional medical help, use over-the-counter drugs, and may miss school or work days. The annual cumulative societal cost of the common cold in the United States is billions of dollars. No vaccines are available. The primary method to prevent the infection is hand washing to minimize person-to-person transmission of the virus. There are no antiviral drugs approved to treat or cure the infection. Most available medications are palliative and treat symptoms only. Megadoses of vitamin C, preparations from echinacea, and zinc gluconate have been studied as treatments for the common cold, though none have been approved by the Food and Drug Administration or European Medicines Agency.

Common cold was first considered a distinct diagnosis by Benjamin Franklin in the 18th century.

There is no established classification system for acute viral nasopharyngitis.

Rhinovirus (the most common cause of common cold) is usually transmitted via aerosols generated by coughing or sneezing. The entry point is usually the nose, however viruses can enter the body through the lacrimal ducts. Following transmission, the virus invades epithelial cells and causes a release of inflammatory cytokines, leading to the various symptoms of the common cold. The body responds using cellular and humoral immunity in addition to the role of bacterial flora in the defense against the organism.

Acute viral nasopharyngitis is most commonly caused by an infection with rhinovirus. Other common causes include coronavirus, human parainfluenza viruses, and human respiratory syncytial virus (RSV).

Acute viral nasopharyngitis should be differentiated from other diseases that cause runny nose, cough, and constitutional symptoms such as influenza, allergic rhinitis, and acute sinusitis.

Acute viral nasopharyngitis is the most common human infection worldwide, responsible for about half of all family physician visits. On average, adults get 2-3 common cold bouts per year and children get 6-10 infections per year and 500 out of every 1,000 family physician visits per year are due to acute viral nasopharyngitis. Males are more likely to be affected than females and Native Americans are more prone to develop complications.

Common risk factors for acute viral nasopharyngitis include having contact with an infected patient, spending time in daycare centers, presence of allergic rhinitis or immunocompromisation.

Despite that infection with common cold tend to have a seasonal pattern, there is no proven association between cold exposure or chilling and the occurrence of common colds.

If left untreated, common cold resolves completely within 7-10 days. Common complications of acute viral nasopharyngitis include sinusitis, otitis media, and exacerbation of reactive airway disease. Prognosis is generally excellent. 50% of patients recover completely within 7 days and 90% of patients recover within 15 days.

Symptoms of acute viral nasopharyngitis include runny nose, cough, and sore throat.

Patients with acute viral nasopharyngitis usually appear ill. Physical examination of patients with acute viral nasopharyngitis is usually remarkable for runny nose, hyperemic nasal mucosa, and mild cervical lymphadenopathy.

Laboratory findings consistent with the diagnosis of acute viral nasopharyngitis include positive viral culture, positive PCR, and leucocytosis in CBC.

There are no X-ray, CT, MRI, or ultrasound findings associated with acute viral nasopharyngitis.

The mainstay of therapy for acute viral nasopharyngitis is symptomatic treatment using palliative measures like fluids, rest and throat sprays. Analgesics, nasal decongestants and cough suppressants can be used to alleviate the symptoms. Antibiotics have no use in common cold as the disease is viral in origin and there is no approved antiviral drug for the common cold. Mega doses of vitamin C, Zinc and steam inhalation are not proved to be of benefit in treating common cold despite the wide belief of their use.

Surgical intervention is not recommended for the management of acute viral nasopharyngitis.

Effective measures for the primary prevention of acute viral nasopharyngitis include avoiding close contact with patients and washing hands regularly.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Common cold was first considered a distinct diagnosis by Benjamin Franklin in the 18th century.

• In the 18th century, Benjamin Franklin considered the causes and prevention of the common cold.
• After several years of research, he concluded that “People often catch a cold from one another when shut up together in small close rooms, or coaches; and when sitting near and conversing, so as to breathe in each other’s transpiration.”
• Although viruses had not yet been discovered, Franklin hypothesized that the common cold was passed between people through the air.
• He recommended exercise, bathing, and moderation in food and drink consumption to avoid the common cold.^[1] Franklin’s theory on the transmission of the cold was confirmed about 150 years later.^[2]

• In the United Kingdom, the Common Cold Unit (CCU) was set up by the civilian Medical Research Council in 1946. The unit worked with volunteers who were infected with various viruses.^[3]

• The rhinovirus was discovered in the CCU in the 1950s; scientists were able to culture the virus on a tissue culture.
• In the 1970s, the CCU proved that using interferon during the incubation period could be potentially protective against developing the infection.
• In 1987, the unit completed its research on zinc gluconate lozenges for prophylaxis against rhinovirus.^[4]
• In 1989, the unit was closed.^[5]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

​There is no established classification system for acute viral nasopharyngitis.

​There is no established classification system for acute viral nasopharyngitis .

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Rhinovirus (the most common cause of common cold) is usually transmitted via aerosols generated by coughing or sneezing. The entry point is usually the nose, however viruses can enter the body through the lacrimal ducts. Following transmission, the virus invades epithelial cells and causes a release of inflammatory cytokines, leading to the various symptoms of the common cold. The body responds using cellular and humoral immunity in addition to the role of bacterial flora in the defense against the organism.

Common colds are most often caused by one of more than 100 serotypes of rhinoviruses, a type of picornavirus. Other viruses that can cause colds are coronavirus, human parainfluenza viruses, human respiratory syncytial virus, adenoviruses, enteroviruses, and metapneumovirus.^[1][2][3]

The common cold virus is transmitted between people by one of two ways:

1. Aerosols generated by coughing and sneezing
2. Saliva or nasal discharge, either directly or from contaminated surfaces

• Asymptomatic patients can transmit the infection, too.^[4]
• The infectious period (i.e. the time during which an infected person can infect others) begins about one day before symptoms begin and continues for the first five days of the illness.
• The virus enters the cells of the epithelium of the nasopharynx and rapidly multiplies.
• The virus enters the body mainly through the nose. Other entry points include the eyes through drainage of tears from the lacrimal ducts into the nasopharynx.

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• Viruses undergo frequent changes in their antigenic coat. This helps them evade the immune system and enables them to cause recurrent infections.
  • Rhinovirus binds to ICAM-1 receptors on epithelial cells and makes them release inflammatory cytokines, but does not cause damage to them.
  • Respiratory syncytial virus (RSV) does not cause any release of cytokines. Instead, it replicates in the nose and pharynx. In many occasions, it can spread to the lower respiratory tract.^[5]
  • Human parainfluenza virus causes inflammation of the respiratory tract, so parainfluenza infection is much more severe than other viruses.
• The body fights the offending viruses using both humoral immunity (i.e. IgA in the epithelium), and cell mediated immunity (i.e. different inflammatory cells in the adenoids and tonsils).^[3]
• Normal flora inhabitants in the nasopharynx also play an important role in eliminating the infection.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Acute viral nasopharyngitis is most commonly caused by an infection with rhinovirus. Other common causes include coronavirus, human parainfluenza viruses, and human respiratory syncytial virus (RSV).

Common colds are most often caused by one of more than 100 serotypes of rhinovirus, a type of picornavirus.^[1]

Other viruses that cause colds include:^[2][3][4]

• Coronavirus
• Human parainfluenza viruses
• Human respiratory syncytial virus (RSV)
• Adenoviruses
• Enteroviruses
• Metapneumovirus

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Acute viral nasopharyngitis should be differentiated from other diseases that cause runny nose, cough, and constitutional symptoms, such as influenza, allergic rhinitis, and acute sinusitis.

Acute viral nasopharyngitis should be differentiated from other diseases that cause runny nose, cough, and constitutional symptoms.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Acute viral nasopharyngitis is the most common human infection worldwide, responsible for about half of all family physician visits. On average, adults get 2-3 common cold bouts per year and children get 6-10 infections per year and 500 out of every 1,000 family physician visits per year are due to acute viral nasopharyngitis. Males are more likely to be affected than females and Native Americans are more prone to develop complications.

• Upper respiratory tract infections are the most common human infections worldwide.^[1]
• On average, adults get 2-3 common cold bouts per year and children get 6-10 infections per year.^[2]
• Acute viral nasopharyngitis is responsible for 500 out of every 1,000 family physician visits per year.^[3]

• Acute viral nasopharyngitis infection is more common among infants and elderly people who have decreased immunity.
• Elderly people > 65 years tend to have a more severe form of the disease, even developing complications.^[4]

• Males are more commonly affected by the common cold than females in all age groups, especially in young children and the elderly.^[5]

• Native Americans and Inuits are more likely to contract the disease and develop complications.^[2]

• Acute viral nasopharyngitis is prevalent worldwide with no specific predilection.

• In the United States, the incidence of colds is higher in the fall and winter, with the highest rate between September and April.
• The higher incidence during this time of the year may be due to cold weather and the school season. These factors encourage people to stay indoors in close proximity, increasing the chance of contracting the infection.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Common risk factors for acute viral nasopharyngitis include having contact with an infected patient, spending time in daycare centers, presence of allergic rhinitis or immunocompromisation.

Despite that infection with common cold tend to have a seasonal pattern, there is no proven association between cold exposure or chilling and the occurrence of common colds.

Common risk factors for acute viral nasopharyngitis include:

• Ill contact
• Attending daycare centers (for infants and children)
• Allergic rhinitis or sinusitis
• Asthma
• Being immunosuppressed (i.e. in HIV or hematologic malignancy)^[1]

• Despite the fact that most common colds occur in fall and winter, there is no proven association between cold exposure or chilling and the occurrence of common colds.^[2][3]
• Regarding the causation of cold-like symptoms, researchers at the Common Cold Centre at the Cardiff University conducted a study to test the hypothesis that “acute cooling of the feet causes the onset of common cold symptoms.” The study measured the subjects’ self-reported cold symptoms and their belief of having a cold; but not whether an actual respiratory infection developed. The researchers concluded that common cold symptoms can be generated by acute chilling of the feet, but “further studies are needed to determine the relationship between symptom generation with any respiratory infection.”^[4]

Less common risk factors include:

• Pregnant women are at increased risk of contacting the common cold for up to 2 weeks after delivery. Although, Breastfeeding decreases the risk of contacting the common cold
• Old age (> 65 years)
• Morbid obesity (BMI > 35)^[5]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

According to the USPSTF, screening for Acute viral nasopharyngitis is not recommended.

According to the USPSTF, screening for Acute viral nasopharyngitis is not recommended.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

If left untreated, the common cold resolves completely within 7-10 days. Common complications of acute viral nasopharyngitis include sinusitis, otitis media, and exacerbation of reactive airway disease. Prognosis is generally excellent: 50% of patients recover completely within 7 days, while 90% of patients recover within 15 days.

If left untreated, the common cold resolves completely within 7-10 days.^[1]

The majority of common cold bouts are passed without complications. However, complications might develop due to swelling of the nasal mucosa, which facilitates infection in the lower respiratory tract or the middle ear mucosa.^[2][3]

The common cold may cause obstruction of Eustachian tubes, predisposing the patient to otitis media.

Sinusitis is suspected when the symptoms of common cold are prolonged or not respond to treatment.

Although rhinovirus does not usually invade the lower respiratory tract mucosa, it may facilitate the invasion of other viruses or bacteria.

Rhinovirus infections has been known to be coomplicated with acute asthma attacks.

Prognosis is generally excellent, with 50% of patients recovering completely within 7 days, and 90% recovering within 15 days.^[1]

Complications usually occur in immunocompromised patients or patients at both age extremes.