Asthma may prompt sickle cell pain in children

NEW YORK – Painful episodes in children with sickle cell disease (SCD) and asthma are temporally associated with respiratory symptoms, doctors from St. Louis, Missouri, have noticed. “In children SCD and asthma, respiratory symptoms are a risk factor for painful SCD episodes within 96 hours,” they report.

SCD is an inherited disorder most common among African Americans that causes normally round blood cells to take on a “sickle” shape, which interferes with normal circulation and can cause a variety of serious health problems.

The sickled cells can block tiny blood vessels called capillaries, which is extremely painful and can lead to organ and tissue damage. These “painful episodes” are the most common sequelae of SCD and individuals with frequent painful episodes are at heightened risk for premature death.

Previous studies have established a link between asthma and an increased rate of painful SCD episodes. However, little is known about the temporal relationship between respiratory symptoms and painful episodes.

To investigate, Dr. Jeffrey Glassberg and colleagues analyzed a total of 124 painful episodes experienced by 74 children over 25 months. Thirty-six of the children had asthma and 38 did not. Their mean age was 9.8 years.

Of the 94 painful episodes (76 percent) with proper documentation of the presence or absence of respiratory symptoms, 54 percent occurred in children with asthma and 46 percent in children without asthma.

Thirty-five percent of painful episodes were clearly preceded by respiratory symptoms in children with asthma compared with 12 percent in children without asthma — a 23 percent difference, Glassberg and colleagues report.

Asthmatic children were also more apt to have respiratory symptoms concurrent with painful episodes. The odds ratio of having a painful episode antecedent or concurrent with mild respiratory symptoms was 4.9 in children with asthma compared to those without.

The authors say their results “provide further evidence that asthma is a potentially modifiable risk factor associated with painful events in children with SCD. “

“Further prospective studies,” they conclude, “may answer the question of whether early treatment of asthma exacerbations can prevent painful episodes.”