What’s new in atopic eczema? An analysis of systematic reviews published in 2017. Part 2: epidemiology, aetiology and risk factors

Abstract

This article forms part of a series of annual updates that summarizes the evidence base for atopic eczema (AE). It provides a summary of key findings from 28 systematic reviews that were published or indexed during 2017, and focuses on the epidemiology, aetiology and risk factors of AE. AE is the largest single contributor to morbidity associated with skin disease worldwide, once mortality has been excluded. There is a high prevalence of sleep disturbance in individuals with AE and they take more sick leave than controls. While there is a lack of skin bacterial diversity in patients with AE, there is a relative abundance of Staphylococcus aureus and Staphylococcus epidermidis. Compared with controls, affected individuals more often show an IgE response to S. aureus antigens and have higher serum interleukin-31 levels. Early antibiotic exposure, environmental pollutants, maternal atopy and food allergy are associated with an increased risk of AE, and very preterm birth is associated with decreased risk. Patients with AE have a reduced risk of meningioma, but are more likely to develop attention-deficit hyperactivity disorder compared with controls. Patients with eosinophilic oesophagitis are significantly more likely than unaffected individuals to have AE. There is no significant overall association between AE and allergic contact dermatitis (ACD), and in children referred for patch testing, ACD was more common in those without AE. Hand eczema is more prevalent in patients with AE. There is no association between AE and Type 2 diabetes, hypertension, stroke or myocardial infarction.

Prenatal antibiotic exposure and the risk of atopic dermatitis in children: a nationwide population-based cohort study.

“…24 Based on the covariates they adjusted for, we further adjusted the maternal comorbidities, maternal AD, maternal allergic rhinitis, gestational infections, and maternal acetaminophen use during pregnancy, which may be potential risk factors according to previous studies. 12,25,26 In addition, their study revealed an apparent doseresponse relationship, and the category of infection did not modify the association of maternal antibiotic use and child AD, which was consistent with our results. In terms of the trimester-specific association between antibiotic exposure during pregnancy and childhood AD, their results were comparable with our results in that the risk increased in all trimesters; however, our data showed a slightly higher risk in the first and second trimesters compared with the third trimester, which might be explained by antibiotics-related dysbiosis or immunomodulatory effects, phenomena that are known to have a greater impact during early pregnancy.…”

A new era of atopic eczema research: Advances and highlights

“…A variety of intrinsic and extrinsic risk factors were identified to influence AE development and exacerbation (Figure 1). 19 Intrinsic risk factors for AE include parental atopic history, filaggrin (FLG) mutations, polysensitization, decreased short‐chain fatty acids in the gut of children, and underlying medical conditions as keratoconus 20‐25 . However, extrinsic factors as low microbial exposure and diversity, antibiotic exposure, urban environment, tobacco smoke exposure, stress, food and pollutants are as important for AE development 16 .…”

“…However, contradicting results exist on the influence of dog and cat ownership on disease development 32,33 . Also, caesarean section birth with lower microbial exposure could recently not be confirmed to have a higher risk for AE than vaginal delivery, 34 whereas very preterm birth even seems to be associated with decreased risk for AE development 20,21 . A deeper understanding of the complex interplay between microbes and host is still needed 35 .…”

“…32,33 Also, caesarean section birth with lower microbial exposure could recently not be confirmed to have a higher risk for AE than vaginal delivery, 34 whereas very preterm birth even seems to be associated with decreased risk for AE development. 20,21 A deeper understanding of the complex interplay between microbes and host is still needed. 35 Another environmental factor is the surrounding climate in a given location, a combination of temperature, and precipitation and therefore UV exposure and humidity.…”

Factors associated with the development of skin allergies in premature newborns in the first year of life

“…Environmental aspects (pollutants) and food allergies can contribute to the development of eczema (6) . However, according to international studies, family history, diseases and complications of the perinatal period, including prematurity and its neonatal complications (jaundice, early antimicrobial exposure, lung diseases), are the main predisposing factors for the development of eczema (7)(8) .…”