Fish consumption, fish atopy and related heavy metals in childhood eczema

Due to increasing worldwide water pollution, fish might be a source of excessive zinc, mercury, arsenic or manganese intake. The aim of this study was to evaluate if fish atopy/sensitization and fish consumption behavior are associated with eczema severity and blood levels of the 4 heavy metals.One-hundred and nineteen patients with eczema and 43 patients with miscellaneous non-eczema skin diseases were studied. There were no differences in average weekly fish consumption and blood levels of the 4 heavy metals between eczema and non-eczema groups. Blood levels of these metals were generally within the upper limits of local reference ranges in all these patients. In eczema patients, freshwater fish consumption behavior in days-per-week was correlated with blood arsenic and mercury levels (rho=0.17, p<0.01 for both metals), but not with zinc or manganese. Levels of arsenic and mercury were also correlated with days of seawater fish consumption per week (arsenic: 0.38, mercury: 0.24, p <0.05).Fish sensitization was present in 25% of patients with eczema. Nevertheless, there was no difference in terms of fish consumption behavior, eczema severity, quality of life, and heavy metal levels between eczema patients with or without fish sensitization. We conclude that without exceeding local normal reference ranges, blood arsenic and mercury levels correlated with fish consumption behavior. There is no evidence to suggest that fish sensitization is associated with more severe eczema (bad for eczema), or that patients have milder eczema with more days of fish consumption (good for eczema).