Diagnosis of Asthma in Infants/Children

When is it Asthma?

Signs and symptoms of asthma are not the same with everyone, and they may be mistaken for signs of other common childhood illnesses. Several studies show that as many as 50 to 80 percent of children with asthma develop symptoms before their fifth birthday.

  • Asthma is frequently not diagnosed correctly. This causes many infants and young children to receive improper treatments.
  • Not all wheezes and coughs are caused by asthma, so treatment using asthma medicines is not always right.
  • Frequent fits of coughing, with or without wheezing, are almost always caused by asthma.
  • Coughing may be the child's only symptom of asthma. Wheezing may or may not be present.

It may be Asthma if:

There is a history of repeated:

  • Coughing
  • Wheezing
  • Shortness of breath or fast breathing
  • Chest tightness

Symptoms are made worse by:

  • Viral infection
  • Smokes (tobacco, wood, etc.) or other irritants (like strong perfumes or odors)
  • Exercise or active playing
  • Things the child is allergic to, such as pollen or animal fur
  • Changes in weather/humidity
  • Crying or laughing

Symptoms occur/worsen at night, waking the child and parent

Spirometry (a breathing test) shows airflow problems.

The child responds well to a diagnostic trial of inhaled bronchodilators and anti-inflammatory medications.

No single finding will indicate that the child has asthma, but if the child has several of these findings, it means it is more likely.

Differential Diagnosis for Asthma

Infants and Children

Upper airway diseases

  • Allergic rhinitis and sinusitis

Obstructions involving large airways

  • Foreign body in trachea or bronchus
  • Vocal cord dysfunction
  • Vascular rings or laryngeal webs
  • Laryngotracheomalacia, tracheal stenosis, or bronchostenosis
  • Enlarged lymph nodes or tumor

Obstructions involving small airways

  • Viral bronchiolitis or obliterative bronchiolitis
  • Cystic fibrosis
  • Bronchopulmonary dysplasia
  • Heart disease

Other Causes

  • Recurrent cough not due to asthma
  • Aspiration from swallowing mechanism dysfunction or gastroesophageal reflux

In order to diagnose asthma in a child, health care providers must:

Take a good medical history of the child, including:
  • Symptoms
    • coughing
    • wheezing
    • chest tightness
  • Symptom patterns
    • Seasonal, continual, etc.
    • With exercise or active playing
    • At night, early morning
    • Laughing/crying
    • With triggers
  • Severity
    • Absences from school?
    • Extra doctor visits?
    • ED visits? Hospitalizations?
  • Characteristics of the child's home
  • Triggers and/or aggravating factors
  • Development of disease and current treatment
    • Age of onset and diagnosis
    • History of early-life injury to airways (e.g. respiratory infections, parental smoking)
    • Comorbid conditions (e.g. rhinitis, eczema)
    • Family history of allergies and asthma
    • Progress of the disease (better or worse)
    • Profile of typical exacerbation
    • Impact of asthma on child and family
      • Episodes of unscheduled care
      • Life-threatening exacerbations
      • Absences from/interruptions of school or other activities
      • Activity limitations, especially physical activities
      • History of nighttime awakening with symptoms
      • Effect on growth, development, behavior and school performance, impact on family routines/dynamics/economics
      • Daycare/school characteristics that may interfere with adherence to treatment
    • Present management and response, including plans for managing exacerbations, need for oral corticosteroids (and frequency of use)
    • The child's and family's perceptions of disease
      • Child and parent perception and belief about asthma and medications to treat asthma
      • Ability of child and parents to cope with disease, and to recognize the severity of an attack

Do a complete physical exam, looking for:

  • Wheezing, which may or may not be present with asthma
  • Signs that the child has trouble breathing, including hyperexpansion of the thorax, use of accessory muscles, tachypnea
  • Signs of other allergic diseases, including atopic dermatitis/eczema, clear nasal discharge, swelling of and/or pale nasal mucosa

Do objective measurements, if possible. Consider asthma if any of the above indicators are present, then confirm with spirometry. If the child is too young for spirometry to be done, diagnosis should be made based on the medical history, physical exam and/or response to asthma treatment.

Children with asthma may need additional tests to aid and/or confirm the diagnosis.

  • Bronchoprovocation with cold air, methacholine, or exercise (if negative, may rule out asthma)
  • Child has symptoms (coughing, wheezing, breathlessness, chest tightness), but spirometry is (near) normal
  • Assess diurnal variation of PEF over 1-2 weeks

Asthma Predictive Index

The Asthma Predictive Index (API), is a guide to determining which small children will likely have asthma in later years (i.e., persistent asthma). High-risk children (under age three) who have had four or more wheezing episodes in the past year that lasted more than one day, and affected sleep, are much more likely to have persistent asthma after the age of five, if they have either of the following:

One major criteria:

  • Parent with asthma
  • Physician diagnosis of atopic dermatitis
  • Evidence of sensitization to allergens in the air (i.e., positive skin tests or blood tests to allergens such as trees, grasses, weeds, molds, or dust mites)

OR

Two minor criteria:

  • Evidence of food allergies
  • >4 percent blood eosinophilia (Increased numbers of white blood cells called eosinophils are made by the body to fight off allergic disease. They can collect in tissues and cause damage to the airways of the lung.)
  • Wheezing apart from colds

The Asthma Predictive Index(API) was developed after following almost a thousand children through 13 years of age. Seventy-six (76) percent of children diagnosed with asthma after six years of age had a positive asthma predictive index before three years of age. Ninety-seven (97) percent of children who did not have asthma after six years of age had a negative asthma predictive index before three years of age.

Referral to a Specialist

Referral to a specialist is recommended for consultation or co-management.