By: Dr. Geoffrey Modest
Atopic dermatitis (AD) is pretty common in kids (up to 25%), typically occurring early on (45% of cases begin within first 6 months of life, 60% within first year), and 70% remit spontaneously by adolescence. In those with AD there are significant immunologic changes (increase in Th2 cells and decrease in Th1 cells in their skin, though there are differences in these T-cell subsets in the acute AD phase, with Th2 cells and their associated cytokines of IL-4, IL-5, IL-13 predominating, but in the chronic phase the Th1 cells and their associated IFN-g, IL-5,IL-12 predominate. Vitamin D receptors are all over the body, including in the skin and in the immune system, and a small RCT in AD patients randomized to vitamin D 1,600 IU/d found clinical improvement after 60 days. The current study looked further into the immunologic changes and clinical effects of vitamin D supplementation in AD patients (see Arch Allergy Immunol 2015;166:91–96).
Details:
–39 children with chronic AD (mean age 4, 38% with family history of asthma, 87% family history of allergies, 33% of the kids had asthma and 33% had rhinitis; 8% had mild AD/46% moderate and 46% severe; 90% with total IgE increased and 23% had documented food allergy, 21% for inhalants only; 38% tested positive for dust mite allergen and 44% for eggs. overall skin test positivity was present in 79%). These AD patients were compared with 20 nonallergic healthy controls.
— baseline cytokine (IL-2, IL-4, IL-6, IFN-g, TNF-a) and vitamin D levels were assessed, along with SCORAD (an AD clinical scoring system) index.
–then the patients were treated with vitamin D (1,000 IU/day) for 3 months.
–Families of AD patients were asked not to use topical steroids (6 did use them sporadically) or oral steroids (none used)
Results:
–all cytokines except TNF-a were elevated in the AD kids
–baseline vitamin D levels in the AD and control patients were similar (23 ng/ml in AD group and 20 ng/ml in controls)
–after vitamin D supplementation, the vit D levels increased from 23 ng/ml to 29 ng/ml
–the altered cytokines (IL-2, IL-4, IL-6, IFN-g) were all statistically significantly and dramatically reduced after the vitamin D supplementation, and were within the range of the normal kids
–the SCORAD index decreased from 46.13 +/- 15.68 to 22.57 +/- 15.28, p<0.001) — a SCORAD index of 25-50 reflects moderate AD
In terms of the role of helper T cell subsets, in brief Th1 cells are moere involved in immunity to intracellular pathogens and in autoimmunity; Th2 more with defense against parasites and with atopic diseases. the balance of Th1/Th2 may be important in terms of disease progression. People with higher ratios and HIV infection have slower disease progression. The most significant initial cytokine associated with Th1 is IL-12, and also IFN-g. Th2 is most strongly associated with IL-4.
Although there was no formal control in this study, they did find that those kids who did not adhere to the vitamin D supplementation or did not have much of a bump in their vitamin D levels did not have a significant change in their SCORAD index or cytokine levels. So, given the data that vitamin D may well be important in immune function in general and the results in this and the other study cited above, it certainly seems reasonable to me to check vitamin D levels and supplement in kids with atopic dermatitis.