Beyond the Skin: Reduced Lung Function Associated With Atopic Dermatitis in Infants.

Abstract

Very few studies have examined lung function parameters using tidal breath analysis (TBA) in atopic dermatitis (AD) with its high potential for progression to asthma. To measure lung functions using TBA in infants with AD and in healthy controls (HCs), and to investigate the effects of disease severity, food sensitivity, and history of recurrent wheezing on TBA parameters in infants with AD. Two hundred thirty infants were included in this prospective cross-sectional study, including an AD group (n= 150) and an HC group (n= 80). Food sensitivity was assessed by means of food-specific IgE or the skin prick test. The severity of the disease was evaluated using the SCORing Atopic Dermatitis. Lung function was assessed using TBA. The following TBA parameters were significantly lower in the AD group than in the HC group (P < .05): time to peak tidal expiratory flow, exhaled volume to peak tidal expiratory flow, ratio of time to peak tidal expiratory flow to expiratory time, ratio of exhaled volume to peak tidal expiratory flow to total expiratory volume, expiratory flow when 25% of tidal volume remains in the lungs, respiratory rate, and minute ventilation. No difference was observed in the AD group when TBA parameters were compared according to disease severity, food sensitivity, and history of recurrent wheezing (P > .05). The receiver-operating characteristic curve demonstrated by the ratio of time to peak tidal expiratory flow to expiratory time yielded an area under the curve of 0.826 (CI, 0.772-0.879), with a cutoff value of 31.65 or higher in differentiating AD, with a sensitivity of 78.7% and a specificity of 77.5%. TBA curves can be a useful tool for demonstrating expiratory airway obstruction in AD and for providing objective information for the clinician. Bronchial obstruction was detected in young children with AD irrespective of the severity of the disease, food sensitivity, and history of recurrent wheezing.