Alternaria Sensitization Common in Children With Severe Asthma

ORLANDO – Children with severe asthma may have their already serious symptoms further worsened by sensitization to common household fungi in the genus Alternaria, suggested investigators at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.

Among 187 children with asthma enrolled in the National Heart, Lung and Blood Institutes’ Severe Asthma Research Program (SARP), 28% had a positive skin prick test reaction to Alternaria, reported Dr. Jennifer Shih, an allergy and immunology fellow in the department of pediatrics at Emory University in Atlanta.

Photo courtesy CDC/Dr. Lucille K. Georg

Sensitization to Alternaria was significantly more prevalent among children with severe vs. mild to moderate asthma (P less than .01), and children with severe presentation were significantly more likely to exhibit increased airway hyperresponsiveness (P less than .01) and to report a history of acute or chronic sinusitis requiring antibiotics (P less than .05).

"In the future, routine evaluation of Alternaria sensitization may be useful in the clinical management of children with severe asthma. Future studies are needed to evaluate the mechanistic underpinning of Alternaria sensitization in children with severe asthma," she said.

Sensitization to Alternaria has been associated in other studies with asthma persistence into early adulthood, Dr, Shih said. One study showed that Alternaria sensitization was associated with an odds ratio (OR) of 3.6 for chronic asthma at age 22 years (Lancet 2008;372:1058-64).

Increased airway hyperresponsiveness, a hallmark of severe asthma in children, was associated with Alternaria sensitization in the Childhood Asthma Management Research Program, she noted.

To see whether there were differences in Alternaria sensitization between school-age children with mild to moderate or severe asthma, and whether sensitization was associated with clinical features of asthma severity, Dr. Shih and her colleague Dr. Anne Fitzpatrick took a retrospective look at 187 children enrolled in SARP at their institution. The children ranged in age from 6 to 18 years, and all had skin prick test data available. In all, 90 had severe asthma, and 97 mild to moderate asthma.

Asthma severity was determined according to American Thoracic Society 2000 criteria, which require daily use of systemic or high-dose inhaled corticosteroids, plus at least two of the following: additional controller medication, beta-agonist use on at least 5 of 7 days, a baseline forced expiratory volume in 1 second (FEV₁)less than 80% of predicted, 1 or more emergency department visits within the past year, 3 or more oral steroid burst within the past year, prompt deterioration with steroid reduction, and/or a history of intubation(Am. J. Respir. Crit. Care Med. 2000;162:2341-51).

The investigators also reviewed asthma questionnaires, lung function–testing results, allergy evaluations, and biomarker evaluations.

In an analysis adjusted for race and socioeconomic status, they found that 37% of the children with severe asthma tested positive for Alternaria sensitization, compared with 21% of children with mild-to-moderate disease (adjusted OR 2.13, P = .015).

Among children with severe asthma, Alternaria sensitization was not significantly associated with differences in either blood eosinophil or total serum immunoglobulin E (IgE) levels, or in FEV₁, airflow limitation, air trapping, medication requirements, or health care use.

However, exhaled nitric oxide levels were significantly higher among those with severe asthma and sensitivity to Alternaria (P = .029), as was airway hyperresponsiveness to methacholine challenge (P = .012).

Additionally, in an analysis adjusted for socioeconomic status, children with severe asthma and a positive skin prick test to Alternaria had an adjusted OR for sinusitis of 2.43 (P = .046).

"These findings support previous observations from the Childhood Asthma Management Research Program," Dr. Shih said.

In the question and answer portion of her presentation, several clinicians commented that Alternaria might be a general marker for atopy rather than for airway hyperresponsiveness and sinusitis as seen in her study, and that other allergens such as cockroach and mites might account for exacerbations of severe asthma. Dr. Shih agreed that further studies would help to resolve this question.

The study was supported by the NHLBI and Emory University. Dr. Shih reported that she had no relevant disclosures.

ORLANDO – Children with severe asthma may have their already serious symptoms further worsened by sensitization to common household fungi in the genus Alternaria, suggested investigators at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.

Among 187 children with asthma enrolled in the National Heart, Lung and Blood Institutes’ Severe Asthma Research Program (SARP), 28% had a positive skin prick test reaction to Alternaria, reported Dr. Jennifer Shih, an allergy and immunology fellow in the department of pediatrics at Emory University in Atlanta.

Photo courtesy CDC/Dr. Lucille K. Georg

Sensitization to Alternaria was significantly more prevalent among children with severe vs. mild to moderate asthma (P less than .01), and children with severe presentation were significantly more likely to exhibit increased airway hyperresponsiveness (P less than .01) and to report a history of acute or chronic sinusitis requiring antibiotics (P less than .05).

"In the future, routine evaluation of Alternaria sensitization may be useful in the clinical management of children with severe asthma. Future studies are needed to evaluate the mechanistic underpinning of Alternaria sensitization in children with severe asthma," she said.

Sensitization to Alternaria has been associated in other studies with asthma persistence into early adulthood, Dr, Shih said. One study showed that Alternaria sensitization was associated with an odds ratio (OR) of 3.6 for chronic asthma at age 22 years (Lancet 2008;372:1058-64).

Increased airway hyperresponsiveness, a hallmark of severe asthma in children, was associated with Alternaria sensitization in the Childhood Asthma Management Research Program, she noted.

To see whether there were differences in Alternaria sensitization between school-age children with mild to moderate or severe asthma, and whether sensitization was associated with clinical features of asthma severity, Dr. Shih and her colleague Dr. Anne Fitzpatrick took a retrospective look at 187 children enrolled in SARP at their institution. The children ranged in age from 6 to 18 years, and all had skin prick test data available. In all, 90 had severe asthma, and 97 mild to moderate asthma.

Asthma severity was determined according to American Thoracic Society 2000 criteria, which require daily use of systemic or high-dose inhaled corticosteroids, plus at least two of the following: additional controller medication, beta-agonist use on at least 5 of 7 days, a baseline forced expiratory volume in 1 second (FEV₁)less than 80% of predicted, 1 or more emergency department visits within the past year, 3 or more oral steroid burst within the past year, prompt deterioration with steroid reduction, and/or a history of intubation(Am. J. Respir. Crit. Care Med. 2000;162:2341-51).

The investigators also reviewed asthma questionnaires, lung function–testing results, allergy evaluations, and biomarker evaluations.

In an analysis adjusted for race and socioeconomic status, they found that 37% of the children with severe asthma tested positive for Alternaria sensitization, compared with 21% of children with mild-to-moderate disease (adjusted OR 2.13, P = .015).

Among children with severe asthma, Alternaria sensitization was not significantly associated with differences in either blood eosinophil or total serum immunoglobulin E (IgE) levels, or in FEV₁, airflow limitation, air trapping, medication requirements, or health care use.

However, exhaled nitric oxide levels were significantly higher among those with severe asthma and sensitivity to Alternaria (P = .029), as was airway hyperresponsiveness to methacholine challenge (P = .012).

Additionally, in an analysis adjusted for socioeconomic status, children with severe asthma and a positive skin prick test to Alternaria had an adjusted OR for sinusitis of 2.43 (P = .046).

"These findings support previous observations from the Childhood Asthma Management Research Program," Dr. Shih said.

In the question and answer portion of her presentation, several clinicians commented that Alternaria might be a general marker for atopy rather than for airway hyperresponsiveness and sinusitis as seen in her study, and that other allergens such as cockroach and mites might account for exacerbations of severe asthma. Dr. Shih agreed that further studies would help to resolve this question.

The study was supported by the NHLBI and Emory University. Dr. Shih reported that she had no relevant disclosures.

ORLANDO – Children with severe asthma may have their already serious symptoms further worsened by sensitization to common household fungi in the genus Alternaria, suggested investigators at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.

Among 187 children with asthma enrolled in the National Heart, Lung and Blood Institutes’ Severe Asthma Research Program (SARP), 28% had a positive skin prick test reaction to Alternaria, reported Dr. Jennifer Shih, an allergy and immunology fellow in the department of pediatrics at Emory University in Atlanta.

Photo courtesy CDC/Dr. Lucille K. Georg

Sensitization to Alternaria was significantly more prevalent among children with severe vs. mild to moderate asthma (P less than .01), and children with severe presentation were significantly more likely to exhibit increased airway hyperresponsiveness (P less than .01) and to report a history of acute or chronic sinusitis requiring antibiotics (P less than .05).

"In the future, routine evaluation of Alternaria sensitization may be useful in the clinical management of children with severe asthma. Future studies are needed to evaluate the mechanistic underpinning of Alternaria sensitization in children with severe asthma," she said.

Sensitization to Alternaria has been associated in other studies with asthma persistence into early adulthood, Dr, Shih said. One study showed that Alternaria sensitization was associated with an odds ratio (OR) of 3.6 for chronic asthma at age 22 years (Lancet 2008;372:1058-64).

Increased airway hyperresponsiveness, a hallmark of severe asthma in children, was associated with Alternaria sensitization in the Childhood Asthma Management Research Program, she noted.

To see whether there were differences in Alternaria sensitization between school-age children with mild to moderate or severe asthma, and whether sensitization was associated with clinical features of asthma severity, Dr. Shih and her colleague Dr. Anne Fitzpatrick took a retrospective look at 187 children enrolled in SARP at their institution. The children ranged in age from 6 to 18 years, and all had skin prick test data available. In all, 90 had severe asthma, and 97 mild to moderate asthma.

Asthma severity was determined according to American Thoracic Society 2000 criteria, which require daily use of systemic or high-dose inhaled corticosteroids, plus at least two of the following: additional controller medication, beta-agonist use on at least 5 of 7 days, a baseline forced expiratory volume in 1 second (FEV₁)less than 80% of predicted, 1 or more emergency department visits within the past year, 3 or more oral steroid burst within the past year, prompt deterioration with steroid reduction, and/or a history of intubation(Am. J. Respir. Crit. Care Med. 2000;162:2341-51).

The investigators also reviewed asthma questionnaires, lung function–testing results, allergy evaluations, and biomarker evaluations.

In an analysis adjusted for race and socioeconomic status, they found that 37% of the children with severe asthma tested positive for Alternaria sensitization, compared with 21% of children with mild-to-moderate disease (adjusted OR 2.13, P = .015).

Among children with severe asthma, Alternaria sensitization was not significantly associated with differences in either blood eosinophil or total serum immunoglobulin E (IgE) levels, or in FEV₁, airflow limitation, air trapping, medication requirements, or health care use.

However, exhaled nitric oxide levels were significantly higher among those with severe asthma and sensitivity to Alternaria (P = .029), as was airway hyperresponsiveness to methacholine challenge (P = .012).

Additionally, in an analysis adjusted for socioeconomic status, children with severe asthma and a positive skin prick test to Alternaria had an adjusted OR for sinusitis of 2.43 (P = .046).

"These findings support previous observations from the Childhood Asthma Management Research Program," Dr. Shih said.

In the question and answer portion of her presentation, several clinicians commented that Alternaria might be a general marker for atopy rather than for airway hyperresponsiveness and sinusitis as seen in her study, and that other allergens such as cockroach and mites might account for exacerbations of severe asthma. Dr. Shih agreed that further studies would help to resolve this question.

The study was supported by the NHLBI and Emory University. Dr. Shih reported that she had no relevant disclosures.