Atopy patch testing and associations with atopic conditions and specific IgE tests: a population-based study in adolescents

Background: The clinical usefulness of the atopy patch test (APT) is unclear for investigating aeroallergen- and food-triggered atopic dermatitis (AD). Objectives: This study aimed to assess the prevalence of positive APT reactions in a population of adolescents and investigate possible associations between the APT, specific serum (s) immunoglobulin E (IgE) tests, self-reported atopic conditions and health-related quality of life. Materials & Methods: A population-based study was performed on 211 adolescents (13-14 years old). Collected data included questionnaires, an APT with food and aeroallergens and s-IgE tests. Results: Positive APT reactions were observed in 9.0% (19/211) of the adolescents. Timothy grass was the top allergen with 11 (5.2%) positive reactions, followed by cat dander (2.8%) and house dust mites (2.4%). Rhinoconjunctivitis increased the odds of any positive APT (crude odds ratio: 3.32; 95% confidence interval [CI]: 1.17­9.40), particularly when an APT was positive for aeroallergens (odds ratio: 5.02, 95% CI: 1.54-16.42). There was no association between a positive APT and AD. Four adolescents without AD and no IgE-sensitization had a positive APT. Conclusion: Based on a population of adolescents, the APT is associated with rhinoconjunctivitis but not AD. This finding should be taken into consideration in further attempts to clarify the role of the APT in the clinical setting.

Clinical relevance of positive patch test reactions to lanolin: A ROAT study.

BACKGROUND: Lanolin is often included when patch testing for common contact allergens. The clinical relevance of a positive patch test reaction to lanolin markers is, however, still a subject for debate. OBJECTIVES: To evaluate Amerchol L101 as a marker of lanolin allergy and investigate the clinical impact of lanolin-containing moisturizers on healthy and damaged skin using the repeated open application test (ROAT). METHODS: Twelve test subjects and 14 controls were patch tested with Amerchol L 101 and additional lanolin markers. Subsequently, a blinded ROAT was performed on the arms of the study participants for 4 weeks. Each participant applied a lanolin-free cream base and two different lanolin-containing test creams twice daily on one arm with intact skin and on the other arm with irritant dermatitis, induced by sodium lauryl sulfate (SLS). RESULTS: Eleven test subjects (92%) had positive patch test reactions to Amerchol L 101 when retested and one test subject (8%) had a doubtful reaction. None of the study participants had any skin reactions to the ROAT on intact skin and all participants healed during the ROAT on damaged skin. CONCLUSIONS: Lanolin-containing emollients do not cause or worsen existing dermatitis when performing ROAT in volunteers patch test positive to Amerchol L101.

IgE sensitization in a cohort of adolescents in southern Sweden and its relation to allergic symptoms.

BACKGROUND: There is a strong and consistent association between IgE sensitization and allergy, wheeze, eczema and food hypersensitivity. These conditions are also found in non-sensitized humans, and sensitization is found among individuals without allergy-related diseases. The aim of this study was to analyse the sensitization profile in a representative sample of the population, and to relate patterns of allergens and allergen components to allergic symptoms. METHODS: A population of 195 adolescents took part in this clinical study, which included a self-reported questionnaire and in vitro IgE testing. RESULTS: Sensitization to airborne allergens was significantly more common than sensitization to food allergens, 43% vs. 14%, respectively. IgE response was significantly higher in airborne allergens among adolescents with rhinitis (p < 0.001) and eczema (p < 0.01). Among 53 children with allergic symptoms according to the questionnaire, 60% were sensitized. Sensitization to food allergens was found among those with rhinitis, but only to PR-10 proteins. None of the participants had IgE to seed storage proteins. CONCLUSION: The adolescents in this study, taken from a normal Swedish population, were mainly sensitized to grass pollen and rarely to specific food allergens. The major grass pollen allergen Phl p 1 was the main sensitizer, followed by Cyn d 1 and Phl p 2. Sixty-one percent reporting any allergic symptom were sensitized, and the allergen components associated with wheeze and rhinoconjunctivitis were Fel d 4, Der f 2 and Can f 5.

The Southern Sweden Adolescent Allergy-Cohort: Prevalence of allergic diseases and cross-sectional associations with individual and social factors.

OBJECTIVES: Asthma and allergic diseases are the most frequent chronic diseases in childhood worldwide, and considered a burden for the affected children and their families. The diseases impose an economic burden on society if not diagnosed and treated properly and management of and these diseases are challenging for healthcare professionals. The aim of the present investigation was to assess the prevalence of allergic diseases in an unselected cohort of adolescents in southern Sweden. Additionally, associations with sociodemographic factors were investigated, as well as impact on daily life. METHODS: This cross-sectional study was based on a cohort of n = 1 530 school children, aged 13 to 14, from 13 municipalities in southern Sweden. Data were collected through web-based questionnaires. RESULTS: Of all children 32% reported at least one allergic disease. 67% reported one allergic disease and 33% reported more than one. No allergy-related disease were reported by 68%. Current asthma was reported by 9.8% and current rhino-conjunctivitis was reported by 13%. The prevalence of food hypersensitivity was 12% and the prevalence of eczema was 11%. One to three wheezing attacks were reported from 55% and 40% reported more than four attacks of wheezing in the preceding year. The self-reported allergic diseases were diagnosed by a doctor in; 36% (food hypersensitivity) to 69% (rhinoconjunctivitis) of the cases. CONCLUSIONS: A high number of affected children were identified. Some children being undiagnosed and some not receiving satisfactory treatment. These results suggest that additional studies to evaluate treatment procedures in order to improve healthcare for allergic children are warranted.