Irritant-induced asthma is a rare disease, usually being caused by an accidental or other exceptionally strong exposure to substances irritating the respiratory passages. High-dose inhaled corticosteroid medication is immediately started at the emergency call service. If severe exposure is suspected, it is important to monitor the patient at least for a couple of days in hospital. Immediately after the acute stage diagnostic investigations are carried out, including a metacholine or histamine challenge test, since demonstration of airway hyperreactivity is of diagnostic and prognostic significance. The asthma may remain permanent.