Sibship composition and size alter the risk for atopic dermatitis

Key clinical point: Having siblings and being born second or later is associated with a marginally reduced lifetime risk of developing atopic dermatitis (AD).

Major finding: Children born in the birth order ≥2 vs 1 had a 9% lower risk for ever AD (pooled risk ratio [RR] 0.91; 95% CI 0.84-0.98), and a sibship size ≥2 vs 1 was associated with an 8% lower risk for ever AD (RR 0.92; 95% CI 0.86-0.97) and a 10% lower risk for current AD (RR 0.90; 95% CI 0.83-0.98).

Study details: Findings are from a meta-analysis of 102 observational studies that analyzed the association between birth order or sibship size and the risk for AD.

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Disclosures: This study did not disclose the source of funding. H Kankaanranta declared receiving lecture and consulting fees from various sources. The other authors declared no conflicts of interest.

Source: Lisik D et al. Birth order, sibship size, and risk of atopic dermatitis, food allergy, and atopy: A systematic review and meta‐analysis. Clin Transl Allergy. 2023;13(6):e12270 (Jun 17). Doi: 10.1002/clt2.12270