Recurrent Respiratory Infections in Children

Recurrent respiratory infections are very common in children, but can sometimes be a sign of an underlying medical condition ranging from congenital abnormalities of the lungs to primary immunodeficiency syndromes. Yet, since the average young child has six to ten "colds" a year, it can be hard to know when you should be concerned.

We will take a look at the "normal" frequency of upper and lower respiratory tract infections in children, what is abnormal (such as two or more episodes of pneumonia in 12 months), and some of the potential causes. While most evaluations for frequent infections are normal, diagnosing some of these causes allows for treatment that may reduce long term complications.

Definition

Recurrent respiratory infections can be caused by bacteria, viruses, or fungi, and may involve the upper respiratory tract, lower respiratory tract, or both. A diagnosis usually requires a fever (with a rectal temperature greater than or equal to 38 degrees Celsius) alone with at least one respiratory symptom such as a runny nose, congestion, sore throat, cough, earache, or wheezing. These symptoms should have lasted at least two to three days. Children, especially preschool children, may have as many as seven to ten colds per year.

For infections to be considered "recurrent," they should occur at least two weeks apart with a period of no symptoms in between. That said, there is not a universally held definition of recurrent respiratory infections in children.

Infections involving the upper respiratory tract include:

• Rhinitis (a runny nose)
• The common cold
• Otitis media (middle ear infections)
• Pharyngitis (a sore throat)
• Tonsillitis
• Laryngitis
• Rhinosinusitis
• Sinusitis

Infections involving the lower respiratory tract in children include:

• Bronchiolitis—often caused by respiratory syncytial virus (RSV)
• Bronchitis
• Croup
• Pneumonia

Examples of what may be referred to as "recurrent infections" include:

• Eight or more respiratory infections per year in children under the age of 3, and six or more in children older than age 3
• More than three ear infections in six months (or more than four in 12 months)
• More than five episodes of infectious rhinitis in one year
• More than three episodes of tonsillitis in one year
• More than three episodes of pharyngitis in one year

Incidence and Impact

Recurrent respiratory infections are far too common, with 10% to 15% of children experiencing these infections. Recurrent respiratory tract infections are uncommon in the first six months of life, as antibodies from the mother are still present. After 6 months of age children still have a relative immune deficiency until their immune systems mature at the age of 5 or 6 years old.

In developed countries, recurrent respiratory infections are a major cause of hospitalization, responsible for 8% to 18% of hospitalizations in the UK. In developing countries, the story is grim. Recurrent respiratory tract infections are thought to result in 2 million deaths yearly.

Symptoms

The signs and symptoms of upper respiratory infections are familiar to many people and can include:

• A runny nose (that can be clear, yellow, or green)
• A sore throat
• Swollen tonsils
• Swollen glands (enlarged lymph nodes in the neck)

With lower respiratory tract infections symptoms may include:

• A cough
• Shortness of breath, or physical evidence that breathing is difficult
• Rapid breathing (tachypnea)
• Wheezing
• Cyanosis (a blueish tint to the skin)
• Chest retraction

General Symptoms

It can be difficult to know the source of discomfort upfront in a young child. Symptoms of respiratory tract infections may include fussiness, refusing to eat, lethargy, and more. Your intuition as a parent is very important, as you are familiar with how your child normally behaves. Most pediatricians have learned to listen to a parent's concern above anything else.

Impact and Complications

Recurrent infections can lead to complications, but on their own can have a tremendous impact on both the child and his family.

Physically, experiencing recurrent infections in childhood is a leading cause of bronchiectasis, a type of COPD characterized by dilated airways and excess mucus production. Unfortunately, and despite the widespread use of antibiotics, the incidence of bronchiectasis in the United States is increasing. A reduction in lung function is a serious concern with recurrent lower respiratory tract infections.

Children who experience recurrent respiratory infections also require antibiotics frequently, and antibiotic use has recently been shown to adversely affect the gut microbiome or flora (gut bacteria) and even increase the risk of colon cancer. Antibiotic use can also lead to resistance.

These children also at risk for asthma due to the infections, and in those who have asthma, the infections can trigger an attack.

Emotionally, recurrent infections can affect the whole family. Missing school can result in a child falling behind, and the emotions that follow. They can change family dynamics.

For parents, lost time from work, the economic burden of health care, the stress of having an ill child, and sleep deprivation can add together to further impact the family.

Causes

Respiratory infections in children usually occur due to an imbalance between exposure to infectious diseases (microbial load) and the ability of the immune system to ward off the infection. That said, there are several conditions that may predispose a child to develop an infection, and knowing when to search for an underlying cause is challenging.

Risk Factors

There are several risk factors (not underlying causes). These include:

• Age: A child's immune function doesn't fully develop until the age of 5 or 6 years old.
• Sex: Male children are more likely to experience recurrent respiratory infections than females.
• Exposures: Children who are in a day care setting, those who have siblings (especially siblings who are in school), and those who live in a crowded home environment are more at risk.
• Lack of breastfeeding: The lack of maternal antibodies derived from breastfeeding increases risk.
• Pollutants: Secondhand smoke in the home and outdoor air pollution increase risk. Risk is also higher among children whose mothers smoked during pregnancy.
• Pets in the home (especially cats and dogs)
• Winter months
• Malnutrition
• Low socioeconomic status
• Physical stress
• A history of allergies or eczema in a child or in his family
• A history of gastroesophageal reflux
• Premature birth or low birth weight
• Behind on or absence of immunizations
• Pacifier use
• Bottle feeding while lying prone (on their stomach)
• High humidity with a damp home environment

Microorganisms

There are a number of bacteria and viruses that are most commonly found in children with recurrent respiratory infections. Episodes usually begin with a viral infection with a secondary bacterial superinfection (the viral infection creates a setting in which bacteria can flourish more easily). It is this combination of a viral infection and secondary bacterial infection that is responsible for the danger associated with the flu virus.

• Common viruses include: respiratory syncytial virus (RSV), rhinoviruses, influenza viruses
• Common bacterial infections include those caused by Streptococcus pneumoniae, Mycoplasma pneumonia, Haemophilus influenza, and Streptococcus pyogenes

That immunizations are available for several of these infections emphasizes the importance of vaccinations in children.

Underlying Causes

As noted, recurrent respiratory infections are common in children and most often are related to the lack of a fully mature immune system sometimes combined with the risk factors above. In some cases, however, an underlying medical condition (either present from birth (congenital) or acquired later on) is present. Underlying causes can be divided into categories:

• Anatomic abnormalities
• Functional abnormalities
• Secondary immunosuppression
• Primary immunodeficiency disorders

Anatomic Factors

There is a wide range of conditions that may predispose a child to repeated respiratory infections. Some of these include:

• Congenital abnormalities of the upper or lower airways, such as bronchial hypoplasia or bronchial stenosis, tracheal conditions such as tracheomalacia, and more
• Nasal polyps, deviated nasal septum
• Foreign body in the airways (either in the nasal/sinus passages or bronchial tree)
• Tuberculosis
• Abnormalities of the head/face (craniofacial abnormalities)

Functional Factors

Possible function related causes include:

• Post-nasal drip
• Eustachian tube dysfunction
• Asthma, allergies
• Cystic fibrosis
• Gastroesophageal reflux
• Ciliary dyskinesis or immotile cilia syndrome: When the tiny hairs that line the airways do not function properly to remove debri from the airways
• Alpha-1 antitrypsin deficiency
• Neurological conditions that interfere with swallowing (which can lead to aspiration)

Secondary Immunodeficiency

There are several conditions and treatments that can reduce the ability of a child's immune system to fight off the infections associated with recurrent respiratory infections. Some of these include:

• Infections, such as HIV, Epstein-Barre virus (EBV, the virus that causes "mono"), cytomegalovirus (CMV)
• Medications, such as corticosteroids (such as prednisone), chemotherapy
• Blood-related cancers such as leukemia and lymphoma
• Asplenia (lack of a spleen or splenic function), such as with hereditary spherocytosis, sickle cell disease, or children who have had a splenectomy due to trauma
• Malnutrition

Primary Immunodeficiency Disorders

Primary immunodeficiency disorders are an uncommon cause of recurrent respiratory infections in children, but are thought to be underdiagnosed. While uncommon, diagnosing and treating some of these conditions may not only reduce the number of infections, but minimize long term lung damage as well.

There are over 250 types of primary immunodeficiency disorders, and these can include problems with antibody production, T cell disorders, complement disorders, phagocyte disorders, and more, though antibody disorders are a frequent culprit when recurrent respiratory infections occur.

Some of these disorders may not be diagnosed until adulthood, whereas the more severe disorders are usually evident early in life. They most commonly present between the ages of 6 months and 2 years—after maternal antibodies are no longer present.

A few examples of primary immunodeficiency disorders that may be associated with recurrent respiratory infections include:

• Selective IgA deficiency: Present as frequently as 1 in 170 people (and thought to be 10 times more common in children who experience recurrent respiratory infections), selective IgA deficiency is also associated with allergies, celiac disease, and autoimmune diseases. Often thought to be of minor importance (many people go through life without ever being diagnosed), diagnosing the condition can be helpful with children having frequent infections.
• Common variable immunodeficiency (CVID)
• X-linked agammaglobulinemia
• IgG subclass deficiencies
• Polysaccharide antibody deficiency
• Hyper IgM syndrome
• DiGeorge syndrome: In addition to immunodeficiency, children with the syndrome may have birth defects such as congenital heart disease. It is thought to occur in roughly 1 in 4,000 children.
• Wiskott-Aldrich syndrome

Diagnosis

If you and your pediatrician believe that your child might possibly have an underlying reason for recurrent respiratory infections, a thorough history and physical exam as well as additional testing is often done. It's important to note, however, that very often a clear cause is not found. But when might a further evaluation be needed?

When to Be Concerned

There are a number of situations that might suggest an underlying anatomic or immunodeficiency problem. When figuring out the number of infections, it's important to note that infections commonly last longer than people realize. In other words, what may appear to be two infections may actually be the same infection that is just lasting longer. The average duration of the common cold is up to 15 days, coughs can last 25 days, and non-specific respiratory symptoms, 16.

Some of these situations include:

• Eight or more ear infections (otitis media) in a one-year period
• Two or more sinus infections in 12 months
• Two or more episodes of pneumonia in 12 months
• Three or more episodes of bronchitis or bronchiolitis
• A productive (wet) cough that lasts more than four weeks (a wet cough could be a symptom of bronchiectasis, cystic fibrosis, immunodeficiencies, foreign body aspiration, congenital lung abnormalities, and more)
• Failure to gain weight
• Thrush (oral candidiasis) infections in the mouth in children over the age of 1 who have not been on antibiotics
• An infection that is persisting despite two months on antibiotics
• Recurrent skin abscesses
• The need for intravenous antibiotics to resolve an infection
• The need for preventive antibiotics
• A family history of primary immunodeficiency (most children who have a primary immunodeficiency do not have a family history)
• A history of alternating diarrhea and constipation combined with repeated respiratory infections (often seen with cystic fibrosis)
• A history of infections with uncommon organisms

A very important question when considering whether a workup is needed is how a child is doing between infections. In other words, is the child healthy, growing well, and free from symptoms when he does not have an infection?

History

A careful history is often the most important part of a workup for repeated infections. This should include a detailed account of infections in the past, including the severity and treatments used. A family history is also very important.

Physical Exam

There are several things doctors look for when examining a child with recurrent infections.

• Height and weight: These are extremely important measurements. It's helpful to look at a growth chart over time and compare this to normal growth rates for young children to see if there are any changes.
• Head and neck exam: This exam looks for enlarged tonsils or adenoids and the presence of a deviated septum or nasal polyps.
• Chest exam: This is a general overview looking externally for chest deformities (barrel chest, scoliosis). The chest exam also looks for abnormal breath sounds, respiratory rate, and use of accessory muscles for breathing.
• Extremities: Digital clubbing, a condition in which the fingers take on the appearance of upside-down spoons, may indicate underlying lung disease.

Blood Tests

• Complete blood count (CBC) and differential to look for low levels of white blood cells, red blood cells, or platelets
• HIV test
• Serum immunoglobulin levels (IgG, IgA, IgM): Further testing such as IgG subclasses, lymphocyte analyses, complement studies, etc. are often done by an immunologist)
• Sweat chloride test (screen for cystic fibrosis)
• Ciliary function tests

Imaging Tests

X-ray studies, computed tomography (CT), and/or magnetic resonance imaging (MRI) may be needed if a congenital defect is suspected or to determine the severity of an infection or complications such as bronchiectasis.

Procedures

Procedures that may be considered include:

• Allergy testing
• Nasal endoscopy/ear, nose, throat (ENT) evaluation for conditions ranging from nasal polyps to enlarged adenoids
• Bronchoscopy, especially if a foreign body in an airway is suspected

Treatment

The treatment of recurrent respiratory infections will depend on the underlying cause. Certainly addressing modifiable risk factors is important for all children, such as making sure your child does not have exposure to secondhand smoke.

Immunizations to prevent primary and secondary infections should also be up to date, and are safe and effective even for most children who have immunodeficiency disorders. Vaccines exist for several of the infections that are common in children with recurrent infections. Available vaccines include those for measles, influenza, pertussis (whooping cough), Haemophilus influenzae type b (H. Flu), and Streptococcus pneumonia (the pneumonia vaccine).

Judicious antibiotic treatment is needed when secondary infections occur.

For children with immunodeficiency syndromes, treatment may include immunoglobulin (such as IM or IV gammaglobulin).

Synagis (palivizumab) is a shot that can help protect certain infants and children 2 years old and younger who are at high risk of serious complications from RSV. It's given once a month during the RSV season. Palivizumab is not a vaccine, and it cannot cure or treat a child who is already diagnosed with RSV. If your child is at very high risk for RSV infection, your pediatrician may discuss this option with you.  

A Word From Verywell

Having your child experience recurrent respiratory infections is extremely frustrating as a parent, and you may wish that it was you who had the infections instead. Fortunately, most of the time there is not an underlying reason for the infections, and children outgrow them in time. That said, the recurrent infections themselves need to be addressed to reduce the risk of long term lung damage, and potential underlying causes should be evaluated when indicated for the same reason. Importantly, trust your gut as a parent. If you believe something is wrong, speak up. There is no blood test or X-ray study that can equal a parent's intuition in medicine.