High prevalence of skin test positivity in severe or difficult-to-treat asthma.
BACKGROUND
Skin tests are considered the gold standard for detecting allergen-specific immunoglobulin E (IgE) in the clinical setting and are an important tool for diagnosing and managing allergic asthma.


OBJECTIVE
To assess the prevalence of skin testing in patients > or = 12 years enrolled in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study.


METHODS
Patients were asked whether they had ever been skin tested and, if so, they were asked to provide the test results. Clinical characteristics were used to compare positive (ST+), negative (ST-), and skin test not done (STND) patients.


RESULTS
Of 2,985 patients eligible, 85.8% recalled being skin tested. Of those tested, 93.5% were positive (allergist 95.7%, pulmonologist 87.3%). A high proportion of Whites (93.5%) and non-Whites (94.0%) were ST+; however, more non-Whites had never been skin tested (21.7% vs. 12.3%, respectively; p < 0.0001). Total serum IgE was 104.6 IU/mL for ST+ patients, 87.1 IU/mL for STND patients, and 32.4 IU/mL for ST- patients. Age at asthma onset, duration of asthma, and the prevalence of atopic disorders and asthma triggers differentiated the ST+ from the ST- group. Disease severity appeared similar between the two groups. In general, values for STND patients were closer to the ST+ group, suggesting that those not tested would have been ST+ if administered a test.


CONCLUSIONS
The prevalence of ST+ patients was high in allergy and pulmonology practices, and in White and non-White patients. These data support the utility of a more complete allergic evaluation in severe asthmatics. Skin testing appears associated with disease pathophysiologies in asthma.
Haselkorn
Tmirah
T
Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA. haselkorn.tmirah@gene.com
Borish
Larry
L
Miller
Dave P
DP
Weiss
Scott T
ST
Wong
Dennis A
DA
D000328:Adult; D017668:Age of Onset; D000368:Aged; D000485:Allergens / Q000276:immunology*; D000486:Allergy and Immunology / Q000706:statistics & numerical data; D001249:Asthma / Q000175:diagnosis / Q000276:immunology* / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000453:epidemiology; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015272:Pulmonary Medicine / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D012882:Skin Tests / Q000706:statistics & numerical data*; D044465:White People / Q000706:statistics & numerical data
D000485:Allergens; D007073:Immunoglobulin E