Cough variant asthma

In patients with cough variant asthma (CVA), chronic cough is the main (if not the sole) symptom present associated with airway hyperresponsiveness (1).

• it is considered to be a variant type of asthma as well as a precursor to the development of classical asthma (2)
  • CVA progresses to typical asthma in 17–37% of patients (3)
• mostly seen in children
• the patient may be normal during the day time but cough becomes problematic during the night

In these patients eosinophils in sputum, bronchoalveolar lavage (BAL) fluid, and in bronchial biopsy specimens is characteristic (3).

It is important to differentiate CVA from the so-called eosinophilic bronchitis (EB) (1)

• in eosinophilic bronchitis, patients have cough and eosinophils in sputum but spirometric tests and airway hyperresponsiveness are normal (1)
• 50% of patients with CVA have associated EB (4).

Reference:

1. Global Initiative for Asthma (2023). Global Strategy for Asthma Management and Prevention
2. Matsumoto H et al. Airway wall thickening in patients with cough variant asthma and nonasthmatic chronic cough. Chest. 2007;131(4):1042-9.
3. Gibson PG, Fujimura M, Niimi A. Eosinophilic bronchitis: clinical manifestations and implications for treatment. Thorax. 2002;57(2):178-82.
4. Dicpinigaitis PV.Cough. 4: Cough in asthma and eosinophilic bronchitis. Thorax. 2004 Jan;59(1):71-2.