February 24, 2011
Steroids To Treat Asthma: How Safe Are They?
New study from University of Montreal evaluates impact of steroid use on immune system
Children experiencing an asthma attack who are treated with a short burst of oral steroids may have a transient depression of immune response according to a new study led by Universit© de Montr©al. These findings, published in this month's issue of Pediatric Allergy, Immunology and Pulmonology, have implications for asthmatic children who have flare-ups and who may be exposed to new contagious diseases.
"There is no question that the administration of corticosteroids reduces the risk and duration of hospital admission in children with acute asthma remain the most effective treatment for moderate and severe asthma exacerbations," says first author Francine M. Ducharme, a Universit© de Montr©al professor and paediatrician and researcher at the Sainte-Justine University Hospital Research Center. "However, the safety profile of these medications continues to raise concerns among parents and physicians. New concerns over their possible impact on the immune system stem from rare reports linking or severe chickenpox infections linked with corticosteroid administration."
Reduced immune response to new triggers
Ducharme and colleagues evaluated the immune response of children aged 3 to 17 years, who had arrived at the emergency department (ED) with an asthma attack. All subjects were given immune triggers (known as antigens) and the immune response between those who received corticosteroids versus those who did not were compared.
"Several corticosteroid-treated children had a significantly lower immune response, as measured by the amount of antibody produced, than non-treated kids," says Ducharme.
Reduced immunity only transient
Children enrolled in the study were revaccinated with the antigen five weeks following their initial ED visit. Comparable immune responses were measured in children exposed to oral corticosteroids and not exposed to corticosteroids.
"These findings indicate there is a transient, not sustained, immune suppression in some children exposed to a new antigen at the same time as a corticosteroid administration," says Ducharme.
"In summary, our finding suggest a transient immune suppression occurs in some children who are concomitantly exposed to a new antigen and corticosteroids during an asthma attack, with a recovery within six weeks."
"Given the high frequency of use of these drugs over the past 20 years, the very rare occurrence of severe infectious disease is reassuring and would suggest that the window of risk is very small and only applies to exposure to a new antigen. However, before prescribing oral corticosteroids, it would appear prudent to systematically enquire about recent exposure to chickenpox in children who did not have chickenpox or the vaccine," adds Ducharme. Moreover, all children with asthma who have not had chickenpox should be vaccinated for this condition.
The diagnosis of asthma, which is a chronic inflammatory disease of the lungs, has been significantly on the rise over the last few decades. In 2009, asthma caused approximately 250,000 deaths globally. However, with proper treatment, including the administration of inhaled bronchodilators and corticosteroids, all children with asthma can lead a normal life.
Corticosteroids are anti-inflammatory drugs and are used in asthma to reduce swelling. Strong scientific evidence shows that the use of these medications in patients with moderate to severe acute asthma significantly reduces the rate of hospitalizations and, if admitted, the length of stay in hospital. Consequently, these drugs are and should remain the cornerstone of the treatment of an acute asthma exacerbation.
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