Differential Diagnosis of Asthma

Upon completion of this section, you will be able to

• Identify five conditions that may be confused with asthma in children, and
• Identify five conditions that may be confused with asthma in adults.

The first step in dealing with the asthma patient is to make sure it is asthma. Although, many cases of recurrent cough and wheezing in children and adults are due to asthma, other conditions are often misdiagnosed as asthma. In adults, the differential diagnosis of asthma includes

• Chronic obstructive pulmonary disease (COPD),
• Congestive heart failure,
• Gastroesophageal reflux disease,
• Mechanical obstruction of the airways (e.g., tumors, foreign bodies), and
• Vocal cord dysfunction.

Infrequent causes of wheezing include

• Pulmonary embolism,
• Pulmonary infiltrates with eosinophilia, and
• Some medications (e.g., angiotensin-converting enzyme (ACE) inhibitors) [NHLBI 2007].

In children, chronic cough is a problem, which needs differentiation between asthma and not asthma. Chronic productive cough with purulent sputum is a reason for concern in children and is not usually a symptom of asthma. Nevertheless, respiratory infection presenting purulent sputum can exacerbate asthma in children previously diagnosed with asthma. The younger the child, the greater the need to exclude underlying disease at an early stage [de Jongste and Shields 2003].

Wheezing in children can be an allergic (i.e., asthma) or non-allergic response [Lemanske 2003; Weinberger 2003]. Non-allergic wheezing in children occurs during acute infections, including viral bronchiolitis. Coughing and wheezing in bronchiolitis is difficult to distinguish from asthma. The differential diagnosis of children with frequent respiratory infection and wheezing should include

• Foreign body aspiration causing airway obstruction,
• Pneumonia/bronchiolitis,
• Cystic fibrosis,
• Bronchopulmonary dysplasia (in premature infants),
• Primary ciliary dyskinesia syndrome, and,
• Immune deficiency [NHLBI 2007; GINA 2011].

• Many medical conditions may be confused with asthma at initial diagnosis.
• The most common differential diagnoses of asthma among adults include
  • Chronic obstructive pulmonary disease (COPD),
  • Congestive heart failure,
  • Gastroesophageal reflux disease,
  • Mechanical obstruction of the airways ( e.g., tumors, foreign bodies), and
  • Vocal cord dysfunction.
• The most common differential diagnoses of asthma among children are
  • Foreign body aspiration causing airway obstruction,
  • Pneumonia/bronchiolitis,
  • Cystic fibrosis,
  • Bronchopulmonary dysplasia (in premature infants), and
  • Primary ciliary dyskinesia syndrome.