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Croup, also known as laryngotracheobronchitis, is a type of
respiratory infection Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...
that is usually caused by a
virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...
. The infection leads to swelling inside the
trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from t ...
, which interferes with normal breathing and produces the classic symptoms of "barking/brassy"
cough A cough is a sudden expulsion of air through the large breathing passages that 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 ph ...
, inspiratory
stridor Stridor (Latin for "creaking or grating noise") is a high-pitched extra-thoracic breath sound resulting from turbulent air flow in the larynx or lower in the bronchial tree. It is different from a stertor which is a noise originating in the pha ...
and a hoarse voice.
Fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...
and
runny nose Rhinorrhea, rhinorrhoea, 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 ( hay fever) or certain viral infections, such as the common cold or COV ...
may also be present. These symptoms may be mild, moderate, or severe. Often it starts or is worse at night and normally lasts one to two days. Croup can be caused by a number of viruses including parainfluenza and
influenza virus ''Orthomyxoviridae'' (from Greek ὀρθός, ''orthós'' 'straight' + μύξα, ''mýxa'' 'mucus') is a family of negative-sense RNA viruses. It includes seven genera: ''Alphainfluenzavirus'', ''Betainfluenzavirus'', '' Gammainfluenzavirus'', ' ...
. Rarely is it due to a
bacterial infection Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number ...
. Croup is typically diagnosed based on signs and symptoms after potentially more severe causes, such as
epiglottitis Epiglottitis is the inflammation of the epiglottis—the flap at the base of the tongue that prevents food entering the trachea (windpipe). Symptoms are usually rapid in onset and include trouble swallowing which can result in drooling, changes ...
or an
airway foreign body A foreign body (FB) is any object originating outside the body of an organism. In machinery, it can mean any unwanted intruding object. Most references to foreign bodies involve propulsion through natural orifices into hollow organs. Foreign b ...
, have been ruled out. Further investigations, such as blood tests,
X-rays An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nbs ...
and cultures, are usually not needed. Many cases of croup are preventable by
immunization Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the immunogen). When this system is exposed to molecules that are foreign to the body, called ''non-s ...
for
influenza Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...
and
diphtheria Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and s ...
. Most cases of croup are mild and the child can be treated at home with supportive care. Croup is usually treated with a single dose of
steroids A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and ...
by mouth. In more severe cases inhaled
epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...
may also be used. Hospitalization is required in one to five percent of cases. Croup is a relatively common condition that affects about 15% of children at some point. It most commonly occurs between six months and five years of age but may rarely be seen in children as old as fifteen. It is slightly more common in males than females. It occurs most often in autumn. Before
vaccination Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulat ...
, croup was frequently caused by
diphtheria Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and s ...
and was often fatal. This cause is now very rare in the
Western world The Western world, also known as the West, primarily refers to the various nations and states in the regions of Europe, North America, and Oceania.
due to the success of the diphtheria vaccine.


Signs and symptoms

Croup is characterized by a "barking"
cough A cough is a sudden expulsion of air through the large breathing passages that 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 ph ...
,
stridor Stridor (Latin for "creaking or grating noise") is a high-pitched extra-thoracic breath sound resulting from turbulent air flow in the larynx or lower in the bronchial tree. It is different from a stertor which is a noise originating in the pha ...
, hoarseness, and difficult breathing which usually worsens at night. The "barking" cough is often described as resembling the call of a
sea lion Sea lions are pinnipeds characterized by external ear flaps, long foreflippers, the ability to walk on all fours, short and thick hair, and a big chest and belly. Together with the fur seals, they make up the family Otariidae, eared seals. ...
. The stridor is worsened by agitation or
crying Crying is the dropping of tears (or welling of tears in the eyes) in response to an emotional state, or pain. Emotions that can lead to crying include sadness, anger, and even happiness. The act of crying has been defined as "a complex secr ...
, and if it can be heard at rest, it may indicate critical narrowing of the airways. As croup worsens, stridor may decrease considerably. Other symptoms include
fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...
,
coryza Rhinitis, also known as coryza, is irritation and inflammation of the Mucous membrane of nose, mucous membrane inside the human nose, nose. Common symptoms are a nasal congestion, stuffy nose, rhinorrhea, runny nose, sneeze, sneezing, and post- ...
(symptoms typical of the
common cold 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 fewer than two days after expos ...
), and indrawing of the
chest wall The thoracic wall or chest wall is the boundary of the thoracic cavity. Structure The bony skeletal part of the thoracic wall is the rib cage, and the rest is made up of muscle, skin, and fasciae. The chest wall has 10 layers, namely (from sup ...
–known as Hoover's sign.
Drooling Drooling, or slobbering, is the flow of saliva outside the mouth. Drooling can be caused by excess production of saliva, inability to retain saliva within the mouth (incontinence of saliva), or problems with swallowing (dysphagia or odynophagia ...
or a very sick appearance can indicate other medical conditions, such as
epiglottitis Epiglottitis is the inflammation of the epiglottis—the flap at the base of the tongue that prevents food entering the trachea (windpipe). Symptoms are usually rapid in onset and include trouble swallowing which can result in drooling, changes ...
or tracheitis.


Causes

Croup is usually deemed to be due to a viral infection. Others use the term more broadly, to include acute laryngotracheitis (
laryngitis Laryngitis is inflammation of the larynx (voice box). Symptoms often include a hoarse voice and may include fever, cough, pain in the front of the neck, and dysphagia, trouble swallowing. Typically, these last under two weeks. Laryngitis is c ...
and tracheitis together), spasmodic croup, laryngeal diphtheria, bacterial tracheitis, laryngotracheobronchitis, and laryngotracheobronchopneumonitis. The first two conditions involve a viral infection and are generally milder with respect to symptomatology; the last four are due to bacterial infection and are usually of greater severity.


Viral

Viral croup or acute laryngotracheitis is most commonly caused by parainfluenza virus (a member of the paramyxovirus family), primarily types 1 and 2, in 75% of cases. Other viral causes include
influenza Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...
A and B,
measles Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , cough, ...
,
adenovirus Adenoviruses (members of the family ''Adenoviridae'') are medium-sized (90–100 nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from ...
and
respiratory syncytial virus Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a common, contagious virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. ...
(RSV). Spasmodic croup is caused by the same group of viruses as acute laryngotracheitis, but lacks the usual signs of infection (such as fever, sore throat, and increased
white blood cell count A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cells and ...
). Treatment, and response to treatment, are also similar.


Bacteria and cocci

Croup caused by a bacterial infection is rare. Bacterial croup may be divided into laryngeal diphtheria, bacterial tracheitis, laryngotracheobronchitis, and laryngotracheobronchopneumonitis. Laryngeal diphtheria is due to ''
Corynebacterium diphtheriae ''Corynebacterium diphtheriae'' is the pathogenic bacterium that causes diphtheria. It is also known as the Klebs–Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs (1834–1912) and Friedrich Löff ...
'' while bacterial tracheitis, laryngotracheobronchitis, and laryngotracheobronchopneumonitis are usually due to a primary viral infection with secondary bacterial growth. The most common cocci implicated are ''
Staphylococcus aureus ''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posit ...
'' and ''
Streptococcus pneumoniae ''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They ar ...
'', while the most common bacteria are ''
Haemophilus influenzae ''Haemophilus influenzae'' (formerly called Pfeiffer's bacillus or ''Bacillus influenzae'') is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bact ...
'', and ''
Moraxella catarrhalis ''Moraxella catarrhalis'' is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system, and joints of humans. It causes the inf ...
''.


Pathophysiology

The viral infection that causes croup leads to swelling of the
larynx The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...
,
trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from t ...
, and large
bronchi A bronchus is a passage or airway in the lower respiratory tract that conducts air into the lungs. The first or primary bronchi pronounced (BRAN-KAI) to branch from the trachea at the carina are the right main bronchus and the left main bronchus. ...
due to infiltration of
white blood cells White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from mult ...
(especially
histiocytes A histiocyte is a vertebrate cell that is part of the mononuclear phagocyte system (also known as the reticuloendothelial system or lymphoreticular system). The mononuclear phagocytic system is part of the organism's immune system. The histioc ...
,
lymphocytes A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ada ...
,
plasma cells Plasma cells, also called plasma B cells or effector B cells, are white blood cells that originate in the lymphoid organs as B lymphocytes and secrete large quantities of proteins called antibodies in response to being presented specific substan ...
, and
neutrophils Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying ...
). Swelling produces airway obstruction which, when significant, leads to dramatically increased work of breathing and the characteristic turbulent, noisy airflow known as
stridor Stridor (Latin for "creaking or grating noise") is a high-pitched extra-thoracic breath sound resulting from turbulent air flow in the larynx or lower in the bronchial tree. It is different from a stertor which is a noise originating in the pha ...
.


Diagnosis

Croup is typically diagnosed based on signs and symptoms. The first step is to exclude other obstructive conditions of the upper airway, especially
epiglottitis Epiglottitis is the inflammation of the epiglottis—the flap at the base of the tongue that prevents food entering the trachea (windpipe). Symptoms are usually rapid in onset and include trouble swallowing which can result in drooling, changes ...
, an airway
foreign body A foreign body (FB) is any object originating outside the body of an organism. In machinery, it can mean any unwanted intruding object. Most references to foreign bodies involve propulsion through natural orifices into hollow organs. Foreign b ...
,
subglottic stenosis Subglottic stenosis is a congenital or acquired narrowing of the subglottic airway. It can be congenital, acquired, iatrogenic, or very rarely, idiopathic. It is defined as the narrowing of the portion of the airway that lies between the vocal cor ...
,
angioedema Angioedema is an area of swelling (edema) of the lower layer of skin and tissue just under the skin or mucous membranes. The swelling may occur in the face, tongue, larynx, abdomen, or arms and legs. Often it is associated with hives, which are ...
,
retropharyngeal abscess Retropharyngeal abscess (RPA) is an abscess located in the tissues in the back of the throat behind the posterior pharyngeal wall (the retropharyngeal space). Because RPAs typically occur in deep tissue, they are difficult to diagnose by physical ...
, and bacterial tracheitis. A frontal
X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10  nanometers, corresponding to frequencies in the range 30&nb ...
of the neck is not routinely performed, but if it is done, it may show a characteristic narrowing of the trachea, called the steeple sign, because of the subglottic stenosis, which resembles a
steeple In architecture, a steeple is a tall tower on a building, topped by a spire and often incorporating a belfry and other components. Steeples are very common on Christian churches and cathedrals and the use of the term generally connotes a religi ...
in shape. The steeple sign is suggestive of the diagnosis, but is absent in half of cases. Other investigations (such as
blood test A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a choles ...
s and viral culture) are discouraged, as they may cause unnecessary agitation and thus worsen the stress on the compromised airway. While viral cultures, obtained via
nasopharyngeal The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...
aspiration, can be used to confirm the exact cause, these are usually restricted to research settings. Bacterial infection should be considered if a person does not improve with standard treatment, at which point further investigations may be indicated.


Severity

The most commonly used system for classifying the severity of croup is the Westley score. It is primarily used for research purposes rather than in clinical practice. It is the sum of points assigned for five factors: level of consciousness, cyanosis, stridor, air entry, and retractions. The points given for each factor is listed in the adjacent table, and the final score ranges from 0 to 17. * A total score of ≤ 2 indicates ''mild'' croup. The characteristic barking cough and hoarseness may be present, but there is no stridor at rest. * A total score of 3–5 is classified as ''moderate'' croup. It presents with easily heard stridor, but with few other signs. * A total score of 6–11 is ''severe'' croup. It also presents with obvious stridor, but also features marked
chest wall The thoracic wall or chest wall is the boundary of the thoracic cavity. Structure The bony skeletal part of the thoracic wall is the rib cage, and the rest is made up of muscle, skin, and fasciae. The chest wall has 10 layers, namely (from sup ...
indrawing. * A total score of ≥ 12 indicates impending
respiratory failure Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise ...
. The barking cough and stridor may no longer be prominent at this stage. 85% of children presenting to the emergency department have mild disease; severe croup is rare (<1%).


Prevention

Croup is contagious during the first few days of the infection. Basic hygiene including hand washing can prevent transmission. There are no vaccines that have been developed to prevent croup, however, many cases of croup have been prevented by
immunization Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the immunogen). When this system is exposed to molecules that are foreign to the body, called ''non-s ...
for
influenza Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...
and
diphtheria Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and s ...
. At one time, croup referred to a diphtherial disease, but with vaccination, diphtheria is now rare in the developed world.


Treatment

Most children with croup have mild symptoms and supportive care at home is effective. For children with moderate to severe croup, treatment with corticosteroids and nebulized epinephrine may be suggested. Steroids are given routinely, with
epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...
used in severe cases. Children with
oxygen saturation Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It ca ...
less than 92% should receive oxygen, and those with severe croup may be hospitalized for observation. In very rare severe cases of croup that result in respiratory failure, emergency intubation and ventilation may be required. With treatment, less than 0.2% of children require
endotracheal intubation Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic tube into the trachea (windpipe) to maintain an open airway or to serve as a conduit through which to administer certain drugs. It is frequentl ...
. Since croup is usually a viral disease,
antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and preventio ...
are not used unless secondary bacterial infection is suspected. The use of
cough medicine 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 ...
s, which usually contain
dextromethorphan Dextromethorphan (DXM) is a medication most often used as a cough suppressant in over-the-counter cold and cough medicines. It is sold in syrup, tablet, spray, and lozenge forms. In 2022, the FDA approved a formulation of it combined with b ...
or
guaifenesin Guaifenesin, also known as glyceryl guaiacolate, is an expectorant medication that aids in the elimination of sputum from the respiratory tract. Chemically it is an ether of guaiacol and glycerine. It is often used in combination with other ...
, are also discouraged.


Supportive care

Supportive care for children with croup includes resting and keeping the child hydrated. Infections that are mild are suggested to be treated at home. Croup is contagious so washing hands is important. Children with croup should generally be kept as calm as possible. Over the counter medications for pain and fever may be helpful to keep the child comfortable. There is some evidence that cool or warm mist may be helpful, however, the effectiveness of this approach is not clear. If the child is showing signs is distress while breathing ( inspiratory stridor, working hard to breath, blue (or blue-ish) coloured lips, or decrease in the level of
alertness Alertness is the state of active attention by high sensory awareness such as being watchful and prompt to meet danger or emergency, or being quick to perceive and act. It is related for psychology . A lack of alertness is a symptom of a ...
), immediate medical evaluation by a doctor is required.


Steroids

Corticosteroids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invol ...
, such as
dexamethasone Dexamethasone is a glucocorticoid medication used to treat rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive lung disease, croup, brain swelling, eye pain following eye surgery, superior vena ...
and
budesonide Budesonide, sold under the brand name Pulmicort among others, is a medication of the corticosteroid type. It is available as an inhaler, nebulization solution, pill, nasal spray, and rectal forms. The inhaled form is used in the long-term mana ...
, have been shown to improve outcomes in children with all severities of croup, however, the benefits may be delayed. Significant relief may be obtained as early as two hours after administration. While effective when given
by injection By or BY may refer to: Places * By, Doubs, France, a commune * By, Norway, a village Codes * Belarus ISO country code ** .by, country-code top-level domain for Belarus * Burundi FIPS Pub 10-4 and obsolete NATO digram country code * TUI A ...
, or by inhalation, giving the medication by mouth is preferred. A single dose is usually all that is required, and is generally considered to be quite safe. Dexamethasone at doses of 0.15, 0.3 and 0.6 mg/kg appear to be all equally effective.


Epinephrine

Moderate to severe croup (for example, in the case of severe stridor) may be improved temporarily with
nebulized In medicine, a nebulizer (American English) or nebuliser (British English) is a drug delivery device used to administer medication in the form of a mist inhaled into the lungs. Nebulizers are commonly used for the treatment of asthma, cystic fib ...
epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...
. While epinephrine typically produces a reduction in croup severity within 10–30 minutes, the benefits are short-lived and last for only about 2 hours. If the condition remains improved for 2–4 hours after treatment and no other complications arise, the child is typically discharged from the hospital. Epinephrine treatment is associated with potential adverse effects (usually related to the dose of epinephrine) including
tachycardia Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal ( ...
,
arrhythmia Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adult ...
s, and
hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...
.


Oxygen

More severe cases of croup may require treatment with oxygen. If oxygen is needed, "blow-by" administration (holding an oxygen source near the child's face) is recommended, as it causes less agitation than use of a
mask A mask is an object normally worn on the face, typically for protection, disguise, performance, or entertainment and often they have been employed for rituals and rights. Masks have been used since antiquity for both ceremonial and pra ...
.


Other

While other treatments for croup have been studied, none has sufficient evidence to support its use. There is tentative evidence that breathing heliox (a mixture of
helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic ta ...
and
oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...
) to decrease the work of breathing is useful in those with severe disease, however, there is uncertainty in the effectiveness and the potential adverse effects and/or side effects are not well known. In cases of possible secondary bacterial infection, the antibiotics
vancomycin Vancomycin is a glycopeptide antibiotic medication used to treat a number of bacterial infections. It is recommended intravenously as a treatment for complicated skin infections, bloodstream infections, endocarditis, bone and joint infection ...
and
cefotaxime Cefotaxime is an antibiotic used to treat a number of bacterial infections in human, other animals and plant tissue culture. Specifically in humans it is used to treat joint infections, pelvic inflammatory disease, meningitis, pneumonia, urinar ...
are recommended. In severe cases associated with influenza A or B infections, the
antiviral Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do n ...
neuraminidase inhibitors Neuraminidase inhibitors (NAIs) are a class of drugs which block the neuraminidase enzyme. They are a commonly used antiviral drug type against influenza. Viral neuraminidases are essential for influenza reproduction, facilitating viral budding from ...
may be administered.


Prognosis

Viral croup is usually a self-limiting disease, with half of cases resolving in a day and 80% of cases in two days. It can very rarely result in death from
respiratory failure Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise ...
and/or
cardiac arrest Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possi ...
. Symptoms usually improve within two days, but may last for up to seven days. Other uncommon complications include bacterial tracheitis,
pneumonia 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 severit ...
, and
pulmonary edema Pulmonary edema, also known as pulmonary congestion, is excessive liquid accumulation in the tissue and air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia and respiratory failure. It is due ...
.


Epidemiology

Croup affects about 15% of children, and usually presents between the ages of 6 months and 5–6 years. It accounts for about 5% of hospital admissions in this population. In rare cases, it may occur in children as young as 3 months and as old as 15 years. Males are affected 50% more frequently than are females, and there is an increased
prevalence In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number o ...
in autumn.


History

The word ''croup'' comes from the
Early Modern English Early Modern English or Early New English (sometimes abbreviated EModE, EMnE, or ENE) is the stage of the English language from the beginning of the Tudor period to the English Interregnum and Restoration, or from the transition from Middle E ...
verb ''croup'', meaning "to cry hoarsely." The noun describing the disease originated in southeastern Scotland and became widespread after
Edinburgh Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...
physician
Francis Home Francis Home FRSE FRCPE (17 November 1719 in Eccles, Berwickshire – 15 February 1813) was a Scottish physician, and the first Professor of Materia Medica at the University of Edinburgh, known to make the first attempt to vaccinate again ...
published the 1765 treatise ''An Inquiry into the Nature, Cause, and Cure of the Croup''. Diphtheritic croup has been known since the time of
Homer Homer (; grc, Ὅμηρος , ''Hómēros'') (born ) was a Greek poet who is credited as the author of the ''Iliad'' and the ''Odyssey'', two epic poems that are foundational works of ancient Greek literature. Homer is considered one of the ...
's
ancient Greece Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cu ...
, and it was not until 1826 that viral croup was differentiated from croup due to
diphtheria Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and s ...
by Bretonneau. Viral croup was then called "faux-croup" by the French and often called "false croup" in English, as "croup" or "true croup" then most often referred to the disease caused by the diphtheria bacterium. False croup has also been known as pseudo croup or spasmodic croup. Croup due to diphtheria has become nearly unknown in affluent countries in modern times due to the advent of effective
immunization Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the immunogen). When this system is exposed to molecules that are foreign to the body, called ''non-s ...
. One famous fatality of croup was
Napoleon Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader wh ...
's designated heir,
Napoléon Charles Bonaparte Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader who ...
. His death in
1807 Events January–March * January 7 – The United Kingdom of Great Britain and Ireland issues an Order in Council prohibiting British ships from trading with France or its allies. * January 20 – The Sierra Leone Company, faced with ...
left Napoleon without an heir and contributed to his decision to divorce from his wife, the Empress
Josephine de Beauharnais Josephine may refer to: People * Josephine (given name), a given name (including a list of people with the name) * Josephine (singer), a Greek pop singer Places *Josephine, Texas, United States * Mount Josephine (disambiguation) * Josephine Coun ...
.


References


External links

* {{Respiratory pathology Animal viral diseases Acute upper respiratory infections Pediatrics Wikipedia emergency medicine articles ready to translate Wikipedia medicine articles ready to translate (full) Cough de:Pseudokrupp