Increased risk of idiopathic nephrotic syndrome in children with atopic dermatitis

Clinical and immunological studies have consistently shown a relationship between atopic diathesis and idiopathic nephrotic syndrome (INS). However, no large population cohort study has yet to demonstrate the nature of the relationship between these disorders. Claims data from a random selection of children representing half of the insured population in Taiwan were examined. During the period from 1998 to 2007, we identified 192,295 children aged < 18 years with newly diagnosed atopic dermatitis (AD) and 769,169 frequency-matched controls. Incidence of INS and hazard ratios (HRs) were calculated. The AD cohort had a 2-fold higher overall incidence of INS than the non-AD cohort [7.20 vs. 3.60 per 100,000 person-years, respectively; 95 % confidence interval (CI) 1.50-2.66]. The HR for INS increased with age and was higher among females. The HR for INS was also higher in AD children with more medical visits per year, ranging from 0.94 for those having a parts per thousand currency sign3 visits to 38.6 for those having > 6 visits (trend test P < 0.0001). In particular, the risk of INS clearly increased during the initial 5 years after AD onset. Children with AD have a greater incidence and risk of developing INS and this risk increases with AD severity.