1. Diagnosis
(1) Symptoms and signs.
(2) Investigations.
1.Sputum test: indicator of increased eosinophils.
2. Respiratory function tests: decreased PEF and FEY,.
3.Airway responsiveness: Positive results for BPT and BDT.
4. Arterial blood gas analysis test.
5. Radiological examination: chest X-ray is usually normal but may show hyperinflation in
severe or acute patients.
6. Measurement of specific allergen.