Objectives: to determine frequency and severity of zinc deficiency in AD children, and find out if there is any association between zinc level and AD severity or body mass index.
Methods: retrospective, case control study. Review of records of all children (<14 years) seen at Ped Allergy-Immunology clinics of Hamad General Hospital during Jun 2014-2015 with severe AD who had zinc level tested. In addition to demographic data, lab. tests (CBC with differential, IgE, serum zinc, vitamin D, food allergens tests of SPT or specific IgE), SCORAD and weight and height were collected.
Results: 23 children (out of 130 children, 17.7%) were found to have serum zinc-low (ZL). We case-controlled them with a group of 23, age-matched, normal-zinc (ZN) AD children. The 2 groups were similar in age (48 vs. 46 months), sex, co-existing allergies (26.1%) vs 26.1%), and no. of positive food allergens per patient (1.9 vs 2) and type of food allergens. ZL had higher positive family history of allergies (91.3% vs. 69.6%) and parental consanguinity (39.1% vs 26.1%) than ZN. Besides ZL had higher WBC (15,554 vs. 11,223 cells/ul), peripheral blood eosinophils (846 vs 685 cells/ul), and IgE (3,132 vs. 2,086 Ku/L), but lower serum zinc (8.3 vs. 12.3 umol/L) levels, lower BMI (15% vs.18%). Both groups had similar SCORAD (62 vs 63). There was no significant association between zinc level with BMI or SCORAD compared to control group.
Conclusions: Zinc deficiency is quite common among children with severe AD. It seems positive family history and parental consanguinity are risk factors for it. AD zinc deficient children have elevated allergic inflammatory makers irrespective of AD severity.