Asthma may no longer be considered a single disease. Instead, it can be divided into 4 types, claim the authors of a study published in the Journal of Allergy and Clinical Immunology (January 2004).
The new research helps divide ?severe asthma patients into 4 subsets, based on age of onset and presence or absence of eosinophils? (an inflammatory cell), said lead researcher Sally E. Wenzel, MD. The study involved 80 patients with severe asthma. Asthma onset was defined as early or late based on whether the symptoms began before or after the patient had reached 12 years of age. Early-onset asthma was linked with greater allergen sensitivity and more allergic symptoms, compared with late-onset disease. For example, late-onset disease was associated with poorer lung function than earlyonset disease. In both onset groups, the occurrence of eosinophils was connected with greater asthma symptoms and poorer lung function than the absence of such cell.