Asthma in children is a heterogeneous disorder with many phenotypes. This study determined how 161 children with severe asthma are distributed across a cluster analysis.
Severe asthma - differential diagnosis and management (click to enlarge the image). Related: Common Asthma-related Comorbidities. Medscape, 2011, (figure).
Four clusters of asthma were identified:
- Cluster 1 had relatively normal lung function and less atopy
- Cluster 2 had slightly lower lung function, more atopy, and increased symptoms and medication use
- Cluster 3 had greater comorbidity, increased bronchial responsiveness, and lower lung function
- Cluster 4 had the lowest lung function and the greatest symptoms and medication use
Children with severe asthma were present in all clusters, and no cluster corresponded to definitions of asthma severity provided in asthma treatment guidelines.
The study authors concluded that severe asthma in children is highly heterogeneous.
If asthma treatment is not working, check DAT:
- Diagnosis - not asthma at all (VCD, CF, FBA), asthma plus AR, GERD
- Adherence - compliance with medication - 24% of asthma exacerbations are attributable to ICS medication nonadherence (http://goo.gl/1i8ET). Poor adherence to asthma medications (less than 80%) was seen in 75% of children (JACI, 2011).
- Technique - NEB, HFA with spacer, DPI, etc.
3 C's of care - communication, continuity, concordance (finding common ground) are critical for asthma management (http://goo.gl/8gJM6).
Heterogeneity of severe asthma in childhood: Confirmation by cluster analysis of children in the National Institutes of Health/National Heart, Lung, and Blood Institute Severe Asthma Research Program. Fitzpatrick AM, Teague WG, Meyers DA, Peters SP, Li X, Li H, Wenzel SE, Aujla S, Castro M, Bacharier LB, Gaston BM, Bleecker ER, Moore WC; for the National Institutes of Health/National Heart, Lung, and Blood Institute Severe Asthma Research Program. J Allergy Clin Immunol. 2010 Dec 30.
Concepts have changed: “compliance” has been replaced by “adherence” but meaning remains the same: 50% of asthmatic patients are poorly adherent to therapy (http://goo.gl/3en5Q).
Phenotypes for young children with wheezing: "Boys atopic multiple-trigger" and "girls nonatopic uncontrolled wheeze". JACI, 2012.
Comments from Twitter
Craig Canapari @DrCanapari: A lot of what we do in pulmonary clinic is "undiagnose" asthma