Am. J. Respir. Crit. Care Med., Vol 153, No. 2, 02 1996, 597-603.
Airway reactivity changes in asthmatic patients undergoing blinded food challenges
JM James, PA Eigenmann, PA Eggleston and HA Sampson
Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
To investigate the possible pathogenic role of food allergy in asthma,
airway hyperresponsiveness was measured by methacholine inhalation
challenges (MIC) performed before and after double-blind, placebo-
controlled food challenges (DBPCFC) in 26 food-allergic, asthmatic
patients. Airway hyperresponsiveness was classified as severe in two cases
(PD20FEV1 < 2 breath units, BU), moderate in 18 (PD20FEV1: 2-20 BU), and
mild in six (PD20FEV1 > 20 BU). Medications included albuterol (81%),
inhaled steroids (38%), cromolyn (35%), and theophylline (23%). MICs were
performed in the afternoon after DBPCFC. Of the 22 positive DBPCFC, 12
involved chest symptoms (cough, wheezing, or both). Another 10 positive
DBPCFCs included laryngeal, gastrointestinal, and/or skin symptoms without
any chest symptoms. Significant increases in airway hyperresponsiveness
were evident in seven of 12 patients experiencing chest symptoms during
DBPCFC. Significant increases in airway hyperresponsiveness were observed
in one patient without chest symptoms during a positive DBPCFC and one
patient after a negative DBPCFC. However, this last patient had a negative
MIC with the same antigen 1 yr later. These studies indicate that
food-induced allergic reactions can increase airway reactivity, and may do
so without inducing acute asthma.
