Purpose of the Study. Allergen exposure in atopic dermatitis (AD) is a contributing factor in the pathogenesis of this multifactorial disease. This study addressed the effectiveness of allergen avoidance measures in patients with AD by utilization of mattress encasement.
Study Population. Forty adult patients with AD whose treatment consisted of low-potency topical steroids and emollients only.
Methods. Serum was obtained from each participant for total immunoglobulin E (IgE), CD30, IgE-specific antibody to house dust mites (HDM), cat, and Pityrosporum orbicular. Each subject was evaluated by the Severity Scoring of Atopic Dermatitis (SCORAD) index to determine eczema severity as well as skin prick test (SPT) and atopy patch test (APT) for HDM. The active treatment group (n = 22) received occlusive mattress and pillow covers while the placebo group (n = 18) received cotton covers. Participants kept a symptom diary of itch severity. The above lab data and eczema severity were followed over a 12-month period. In addition, dust samples were analyzed for cat and HDM allergen at 3, 6, and 12 months.
Results. The eczema severity by SCORAD index and patient perception of itching was significantly reduced in both the active treatment and placebo groups. The serum CD30 significantly decreased in both groups and seemed to correlate with the eczema severity (P < .001). The HDM-specific IgE was also significantly decreased in both study populations in the last 6 months of the study (P < .05). Elevated HDM allergen concentration was not common in either group; however, for those with detectable levels, exposure significantly decreased in the active treatment group (P < .005). Patients with a positive APT to HDM had a more pronounced reduction of HDM-specific IgE in the active treatment group (P < .05).
Conclusions. Both groups had significant reduction in eczema severity and HDM-specific IgE. One explanation is the allergen reduction capacity of the cotton covers may be similar to occlusive covers in this population with low HDM concentrations. Also participant awareness of dust mite infestation may have altered the cleaning habits of placebo participants. Serum CD30 seemed to correlate with asthma severity suggesting that this may be a useful marker in AD. Sensitization and exposure did not appear to have an effect on the study outcome as nonsensitized and nonexposed individuals benefited equally as compared with sensitized and exposed individuals. This may be explained by reduction of other allergens or irritants.
Reviewers’ Comments. Although allergen exposure plays a role in AD, large studies have not been performed in this population to address the proposed benefits of aeroallergen avoidance. This study suggests that eczema severity, HDM-specific IgE, and CD30 are significantly decreased with occlusive bed covers, however, there was not a statistically significant difference between the study populations. Additionally, HDM allergen in this study was not common and may not be an important factor in the disease process of this population. Future studies should include participants with both sensitization and significant exposure.
- Copyright © 2002 by the American Academy of Pediatrics