. 2008 Nov-Dec;15(Suppl B):1B–19B. doi: 10.1155/2008/973062

TABLE 3.

Main characteristics of patients with slow-onset and sudden-onset acute asthma

Type 1: Slow progression	Type 2: Sudden progression
Slow-onset acute asthma	Sudden-onset, asphyxic, brittle or hyperacute asthma
Progressive deterioration: >6 h (usually days or weeks)	Rapid deterioration: <6 h
80% to 90% who presented to an emergency department	10% to 20% who presented to an emergency department
Female predominance	Male predominance
More likely to be triggered by an upper respiratory tract infection	More likely to be triggered by respiratory allergens, exercise and psychosocial issues
Less severe obstruction at presentation	More severe obstruction at presentation
Slow response to treatment and higher hospital admissions	Rapid response to treatment and lower hospital admissions
Airflow inflammation mechanism	Bronchospastic mechanism of deterioration