Recent NIH-Funded Research Suggest Connection Between Eczema and Food Allergy
First, a brief explanation of Mast Cells. Mast cells live in connective tissue and are part of your body’s immune system. They aid in defense against bacteria and wound healing.
When you scratch your skin, your immune system responds and these mast cells are activated in your small intestine. This skin-gut communication sheds light on the relationship between food allergy and atopic dermatitis (a type of eczema), a disease characterized by dry, itchy skin. The study was supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and led by researchers at Boston Children’s Hospital.
This study suggests people with atopic dermatitis, particularly babies are at a strong risk factor for food allergies. This skin condition makes people itchy, which in turn causes them to scratch. This scratching instigates mast cell expansion in the intestines which in turn leads to food allergies.
The researchers also found that as mast cells expanded, the intestinal lining became more permeable, making it easier for allergens to enter the tissues. Finally, the researchers found that intestinal biopsies from four children with atopic dermatitis contained more mast cells than those from four children without the condition.
Although additional work is needed to determine the relevance of the findings, the researchers suggest that interventions to limit itching potentially could lessen the severity of food allergy among people with atopic dermatitis.
J-M Leyva-Castillo, C Galand, et al. Mechanical skin injury promotes food anaphylaxis by driving intestinal mast cell expansion
Immunity DOI: 10.1016/j.immuni.2019.03.023 (2019).