Comorbidities in childhood atopic dermatitis: A population-based study.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease that is associated with allergic comorbidities. However, studies examining comorbidities in childhood AD are incomplete, which may contribute to suboptimal care. OBJECTIVE: The objective was to compare the risk of developing different allergic and non-allergic comorbidities among children with AD to that of a matched non-AD reference cohort in Sweden. METHODS: This was a nationwide population-based cohort study using longitudinal data from primary and specialist care registers. Patients with AD were identified by confirmed diagnosis in primary or specialist care. The non-AD reference cohort was randomly drawn from the general population and matched 1:1 with the AD patients. The risk of developing the following conditions was evaluated: hypersensitivity and allergic disorders, neurological disorders, psychiatric disorders, infections, immunological and inflammatory disorders, Type 1 diabetes (T1D), endocrine and metabolic disorders, skeletal disorders, ocular disorders and malignancies. RESULTS: This study included 165,145 patients with AD (mild-to-moderate [n = 126,681] and severe [n = 38,464]) and an equally sized reference cohort. Patients with AD displayed a higher risk of developing comorbid conditions for all investigated categories, except for T1D and skeletal disorders, compared with the reference cohort. The highest risk compared with the reference cohort was observed for hypersensitivity and allergic disorders (hazard ratio [HR]: 3.87), followed by malignancies (HR: 2.53) and immunological and inflammatory disorders (HR: 2.36). Patients with AD also had higher risk of developing multiple comorbidities (≥2). The risk of comorbidity onset increased alongside AD severity and patients with active AD were associated with increased risk of comorbidity onset compared with patients in remission. CONCLUSIONS: The clinical burden of AD is substantial for children with AD and patients are at an increased risk of developing several comorbid conditions extending beyond the atopic march. Our results also showed a positive association between worsening severity of AD and an increased risk of comorbidity onset.

Prognosis of Preschool Eczema and Factors of Importance for Remission.

Information on factors of importance for remission of eczema is scarce. This study explored factors related to the remission and course of preschool eczema (PSE) (eczema at 1, 2 and/or 4 years of age) to 16 years of age (n = 889) in a Swedish cohort. Half of the children were in complete remission by school age (at age 8, 12, and 16 years). In multivariate prognostic models, persistent PSE (eczema at 1, 2 and 4 years of age) (odds ratio 0.27 (95% confidence interval 0.18-0.41)), PSE with sleep disturbance (due to itch at least once a week at 1, 2 and/or 4 years of age) (0.59 (0.43-0.81)), parental allergy (0.73 (0.55-0.96)), parental smoking at child's birth (0.70 (0.50-0.99)) and filaggrin mutation (R501X, R2447X, 2282del4) (0.47 (0.26-0.85)) were inversely associated with complete remission by school age. Male sex (1.37 (1.03-1.82)) and exclusive breastfeeding ≥4 months (1.44 (1.01-2.05)) were positively associated with complete remission by school age. In conclusion, half of the children with PSE were in complete remission by school age. The most important prognostic factors were persistent PSE and PSE with sleep disturbance due to itch.