Luftvägsöverkänslighet

Luftvägsöverkänslighet, also known as airway hyperresponsiveness, refers to an exaggerated bronchoconstrictor response of the airways to various stimuli. This condition is a hallmark of asthma, but it can also be present in other respiratory conditions and even in individuals without diagnosed lung disease. The airways of people with luftvägsöverkänslighet are more sensitive to irritants than those of healthy individuals.

When exposed to triggers such as cold air, allergens, dust, smoke, or certain chemicals, the airways in someone with luftvägsöverkänslighet constrict more readily and severely. This constriction, known as bronchospasm, can lead to symptoms like coughing, wheezing, shortness of breath, and chest tightness. The underlying mechanisms involve inflammation and smooth muscle hyperreactivity within the airway walls.

Diagnosing luftvägsöverkänslighet typically involves a bronchial provocation test. In this test, a person inhales increasing doses of a bronchoconstrictor agent, such as methacholine or histamine, or is exposed to non-pharmacological stimuli like exercise or cold air. A significant drop in lung function (measured by forced expiratory volume in one second, FEV1) indicates hyperresponsiveness.

While luftvägsöverkänslighet is a key feature of asthma, its presence does not automatically mean a person has asthma. However, it signifies an increased susceptibility to developing asthma-like symptoms and underscores the importance of identifying and avoiding triggers that can exacerbate airway reactivity. Management often involves avoiding known triggers and, in cases of symptomatic individuals, pharmacological treatments to reduce inflammation and relax airway muscles.