What are the clinical findings in asthma?

Clinical Findings in Asthma

Asthma diagnosis requires recognizing episodic respiratory symptoms combined with objective evidence of variable airflow obstruction, though physical examination findings may be entirely normal between episodes. 1

Key Symptom Patterns

The hallmark clinical features are variable, intermittent symptoms that worsen at night and respond to specific triggers: 1

• Recurrent wheeze (the most important symptom, particularly in children) 1, 2
• Cough (characteristically worse at night) 1
• Shortness of breath 1, 3
• Chest tightness 1, 4

These symptoms are distinguished by their variability and trigger-responsiveness rather than being constant. 1 Patients may be completely asymptomatic between episodes, making timing of examination critical. 1

Common Symptom Triggers

Symptoms occur or worsen with: 1

• Exercise
• Viral respiratory infections
• Inhalant allergens (animals with fur/hair, house-dust mites, mold, pollen)
• Irritants (tobacco smoke, wood smoke, airborne chemicals)
• Weather changes
• Strong emotional expression (laughing or crying)
• Stress
• Menstrual cycles (in women)

Physical Examination Findings

Physical examination may be completely normal, as asthma is variable and signs are often absent between episodes. 1 This is a critical pitfall—normal examination does not exclude asthma. 1

When present during symptomatic periods, findings include: 1

Respiratory System

• Wheezing during normal breathing or prolonged phase of forced exhalation 1
• Hyperexpansion of the thorax 1
• Use of accessory muscles 1
• Hunched shoulders 1
• Chest deformity (in chronic cases) 1

Upper Respiratory Tract

• Increased nasal secretion 1
• Mucosal swelling 1
• Nasal polyps 1

Skin

• Atopic dermatitis 1
• Eczema 1

These skin findings suggest allergic phenotype, which is associated with family history of atopic conditions. 5

Objective Confirmation Required

Spirometry is essential because medical history and physical examination alone are unreliable for excluding other diagnoses or assessing lung status. 1 Patients' perceptions of airflow obstruction are highly variable. 1

Spirometry Findings

• Airflow obstruction (reduced FEV₁ and FEV₁/FVC ratio) 1
• Reversibility: FEV₁ increase of >200 mL AND 12% from baseline after short-acting β₂-agonist 1
• Some evidence suggests 10% of predicted FEV₁ increase may better differentiate asthma from COPD 1

Peak Flow Variability

• Diurnal variation in peak expiratory flow >20% over 1-2 weeks suggests asthma 1
• Peak flow meters are designed for monitoring, not diagnosis, due to wide variability in devices and reference values 1

Special Clinical Phenotypes

Cough Variant Asthma

When cough is the predominant symptom without wheeze, this represents cough variant asthma. 1 These patients have nonproductive cough that responds to standard asthma treatment but not to antibiotics, expectorants, or antitussives. 4

Allergic Asthma

Often associated with personal or family history of atopic conditions (eczema, allergic rhinitis), with symptoms worsening after exposure to pollens, dust, or animals. 5

Critical Diagnostic Pitfalls

The absence of physical findings does not rule out asthma because the disease is variable and signs may be absent between episodes. 1 This is the most important clinical caveat.

Avoid using labels like "wheezy bronchitis," "recurrent pneumonia," or "reactive airway disease" as these can miss the opportunity to diagnose and treat asthma appropriately. 6

Failure to respond to asthma treatment should prompt a search for alternative or additional diagnoses, including: 1

• Foreign body in airway
• Vocal cord dysfunction
• COPD (in adults)
• Congestive heart failure (in adults)
• Gastroesophageal reflux with aspiration

Pediatric-Specific Considerations

In young children, definitive diagnosis is difficult because airway function measurement is often not possible. 1 Asthma should be suspected in any child with wheezing heard by a health professional on auscultation, distinguished from upper airway noises. 1

Male sex is a risk factor for asthma in prepubertal children, while female sex is a risk factor for persistence into adulthood. 1

Maternal history of asthma and/or rhinitis is the strongest family risk factor for childhood asthma. 1