Allergen avoidance is associated with a fall in exhaled nitric oxide in asthmatic children☆,☆☆,★
Section snippets
Patients
Twenty asthmatic children (6 to 15 years) sensitized to HDM were evaluated at the Istituto Pio XII (Misurina BL, Italy) at 1756 m on the Italian Alps. None of them had respiratory infections in the 2 months before and during the study period.
The study was approved by the local ethics committee, and both children and their parents gave informed consent.
Study design
The children had been living with their families for at least 3 months before admission to the residential home (T0). FE NO was measured daily,
RESULTS
The mean levels of HDM group 1 (Der p 1 and Der f 1) antigen in the dust from beds were 13.8 and less than 0.05 μg/g of dust in the family houses and in the residential home, respectively, as measured by means of ELISA.3
FE NO decreased (P = .014 at T1) with a significant effect of the time in the first 2 weeks (P = .0026), remained unchanged from T1 to T2, and at T3 returned approximately to T0 level (P = .004, T2 vs T3; Fig 1).
DISCUSSION
The results of this study suggest that FE NO is modifiable by changes in environmental conditions in asthmatic children. A reduction in other inciters of asthma (eg, air pollution, passive smoke exposure, viral infection, or stress) could also have caused the fall in FE NO, although we believe that HDM reduction is the major factor.
After a significant reduction in the first 2 weeks of avoidance, FE NO did not significantly change from T1 to T2, despite the withdrawal of steroids. Because FE NO
Acknowledgements
We thank Christer Peterson, Pharmacia & Upjohn, Uppsala Sweden, for performing ECP assays.
References (5)
- et al.
Exposure to house dust mite allergens and the clinical activity of asthma
J Allergy Clin Immunol
(1996) - et al.
Monoclonal immunoassay for the major dust mite (Dermatophagoides) allergens, Der p I and Der f I, and quantitative analysis of the allergen content of mite and house dust extracts
J Allergy Clin Immunol
(1987)
Cited by (70)
Inpatient paediatric rehabilitation in chronic respiratory disorders
2012, Paediatric Respiratory ReviewsIt's time to rethink mite allergen avoidance
2011, Journal of Allergy and Clinical ImmunologyClinical effects of purified air administered to the breathing zone in allergic asthma: A double-blind randomized cross-over trial
2009, Respiratory MedicineCitation Excerpt :Movements in bed make the allergens respirable and this exposure may maintain a bronchial inflammation. The fact that avoidance of exposure to indoor allergens could be an important element in the treatment of allergic asthma is shown by studies in mite-allergic children in high altitude environments where a major reduction in mite allergen levels resulted in a significant reduction in bronchial inflammation.3 One limitation of the study is that we did not measure the actual exposure to possible allergens in the breathing zone.
Reply
2007, Journal of Allergy and Clinical ImmunologyExhaled nitric oxide in children with asthma at high altitude
2007, Journal of Allergy and Clinical Immunology
- ☆
Reprint requests: Giorgio L. Piacentini, MD, Clinica Pediatrica, Policlinico Borgo Roma, 37134 Verona, Italy.
- ☆☆
J Allergy Clin Immunol 1999;104:1323-4.
- ★
0091-6749/99 $8.00 + 0 1/1/102444