METHODS: A PubMed search for relevant published articles was conducted using the following search terms singly or in combination: "atopy," "atopic disease," "atopic disorder," "International Study of Asthma and Allergies in Childhood," "ISAAC," "asthma," "allergic rhinitis," "eczema," and "food allergy" in combination with the names of countries of the Arabian Peninsula (Kuwait, United Arab Emirates, Bahrain, Qatar, Oman, Kingdom of Saudi Arabia, and Yemen). The search captured studies published up to December 2017.
RESULTS: A total of 8 publications reporting prevalence rates of any type of atopic disease in children in 7 countries of the Arabian Peninsula were retrieved. The prevalence of all atopic disorders was comparable between countries of the Arabian Peninsula. The overall prevalence of asthma ranged from 8 to 23%, while the reported prevalence of eczema ranged from 7.5 to 22.5%. There was great variation in the prevalence rates of rhinoconjunctivitis, which ranged from 6.3 to 30.5%. The prevalence of food allergy (8.1%) was reported for 1 country only, the United Arab Emirates.
CONCLUSIONS: The reported overall rates of atopic disease in countries of the Arabian Peninsula are comparable to those reported in other industrialized countries. This is probably related to the good economic status in the region, which is reflected in the living standards and lifestyle. Further, genetic factors, such as factors related to gene polymorphism, and the high rate of consanguinity in the region may contribute to the higher prevalence of atopic diseases.
METHODS: Faecal samples were collected at age 1 week, 1 month and 3 months from 117 infants at high risk of allergic disease. Bifidobacterium species were analysed by quantitative PCR and terminal restriction fragment length polymorphism. Infants were examined at 3, 6 and 12 months, and skin prick test was performed at 12 months. Eczema was diagnosed according to the UK Working Party criteria.
RESULTS: The presence of B. catenulatum at 3 months was associated with a higher risk of developing eczema (ORadj = 4.5; 95% CI: 1.56-13.05, padj = 0.005). Infants colonized with B. breve at 1 week (ORadj = 0.29; 95% CI: 0.09-0.95, padj = 0.04) and 3 months (ORadj = 0.15; 95% CI: 0.05-0.44, padj = 0.00001) had a reduced risk of developing eczema. Furthermore, the presence of B. breve at 3 months was associated with a lower risk of atopic sensitization at 12 months (ORadj = 0.38; 95% CI: 0.15-0.98, padj = 0.05). B. breve colonization patterns were influenced by maternal allergic status, household pets and number of siblings.
CONCLUSIONS: Temporal variations in Bifidobacterium colonization patterns early in life are associated with later development of eczema and/or atopic sensitization in infants at high risk of allergic disease. Modulation of the early microbiota may provide a means to prevent eczema in high-risk infants.
OBJECTIVE: This systematic review aims to gather and appraise existing evidence on the associations between serum vitamin D concentrations during pregnancy and at birth and the development of eczema, wheezing, and RTIs in infants.
DATA SOURCES: PubMed, MEDLINE, ProQuest, Scopus, CINAHL, Cochrane Library and Academic Search Premier databases were searched systematically using specified search terms and keywords.
STUDY SELECTION: Articles on the associations between serum vitamin D concentrations during pregnancy and at birth and eczema, wheezing, and RTIs among infants (1-year-old and younger) published up to 31 March 2019 were identified, screened and retrieved.
RESULTS: From the initial 2678 articles screened, ten met the inclusion criteria and were included in the final analysis. There were mixed and conflicting results with regards to the relationship between maternal and cord blood vitamin D concentrations and the three health outcomes-eczema, wheezing and RTIs-in infants.
CONCLUSION: Current findings revealed no robust and consistent associations between vitamin D status in early life and the risk of developing eczema, wheezing and RTIs in infants. PROSPERO registration no. CRD42018093039.