Background: Asthma is the most common chronic disease in children. Cases of severe asthma (SA) are underdiagnosed. Periostin is a biomarker for SA in adults, but its role in children is poorly understood.
Objectives: The aims of the study were to estimate the percentage of cases of uncontrolled severe asthma (UcSA) in children with poorly controlled asthma and to evaluate the role of periostin as a biomarker.
Materials and Methods: We performed an observational study in children aged 5 to 14 years with poorly controlled asthma. Demographic and clinical data were collected in addition to the results of the lung function test, the fraction of exhaled nitric oxide, the skin prick test, total IgE, specific IgE, blood eosinophil count, serum periostin, treatment, asthma control, and quality of life. Variables were compared between the group with UcSA and the other children.
Results: Fifty children with poorly controlled asthma (72% male) were included. Nineteen children (38%) had UcSA. Most children had limitations in their activities of daily living and had visited the emergency department. In addition, 38% were hospitalized. Quality of life was poor. Only 42% of the children received appropriate treatment. The UcSA group was more likely to have a total IgE >500 kUA/mL (52.6% vs 19%, P=.02) and less likely to have serum periostin >1000 ng/mL (31.2% vs 63%, P=.04).
Conclusions: In our setting, 38% of children with poorly controlled asthma have UcSA, which is associated with higher levels of total serum IgE and lower levels of serum periostin.

Key words: Uncontrolled severe asthma, Clinical practice guidelines, Children, Periostin