Patterns of asthma in children
The pattern of asthma determines the need for preventive therapy in children.
Intermittent asthma
Intermittent (formerly termed ‘episodic') asthma is classified as infrequent or frequent.
Infrequent intermittent asthma
Infrequent intermittent asthma is the most common pattern, and occurs in 70%-75% of children with asthma (Figure 1).5 In infrequent intermittent asthma:
- Children have isolated episodes of asthma lasting from 1-2 days up to 1-2 weeks
- Episodes are usually triggered by an upper respiratory tract infection or an environmental allergen
- Episodes are usually more than 6-8 weeks apart and children are asymptomatic in the interval periods.
Severity of infrequent intermittent asthma varies widely. Episodes are usually mild, but children with this pattern account for up to 60% of paediatric hospital admissions.
Children with infrequent intermittent asthma require treatment only during episodes. Regular preventive therapy is not recommended. For more information on the management of infrequent intermittent asthma, see Principles of drug therapy.
Frequent intermittent asthma
Approximately 20% of children with asthma have frequent intermittent asthma:5
- Episodes occur at intervals shorter than 6-8 weeks.
- Children have minimal symptoms (e.g. exercise-induced wheeze) between episodes.
Frequent intermittent asthma is otherwise similar to infrequent intermittent asthma.
Children with frequent intermittent asthma may benefit from regular preventive therapy with leukotriene receptor antagonists, cromoglycate, nedocromil or low-dose (not greater than 200 mcg per day) inhaled corticosteroids. Preventive treatment is commonly required only during the winter months.
Persistent asthma
Approximately 5-10% of children with asthma have persistent asthma:5
- Children have symptoms on most days, often including:
- sleep disturbance due to wheeze or cough
- early morning chest tightness
- exercise intolerance
- spontaneous wheeze.
- Acute asthma episodes may also occur, as for intermittent asthma.
Severity ranges from mild (symptoms 4-5 days per week and readily controlled by low-dose preventive therapy) to severe (frequent severe symptoms and abnormal lung function requiring intensive therapy).
| Figure 1. Frequency of asthma patterns in children |
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| Adapted from Henderson et al, 2004 5 |
| Three out of four children with asthma have infrequent intermittent asthma, while only one in twenty has persistent asthma.5 (Proportions differ between primary school-aged and preschool-aged children.) |
Content Created (Thursday, 16 November 2006)
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