Phenotypes, endotypes and genotypes of atopic dermatitis and allergy in populations of African ancestry on the continent and diaspora.

Atopic dermatitis is a complex inflammatory condition characterized by synergist interactions between epidermal and immune related genotypes, skin barrier defects and immune dysregulation as well as microbial dysbiosis. Ethnicity-specific variations in clinical presentation, immune endotypes and genetic susceptibility have been described in diverse populations. We summarize available data with specific consideration of AD in populations of African ancestry. Some highlights include the observation of AD lesions on extensor surfaces, lichen planus-like AD, prurigo type AD and follicular AD in African populations. In addition, a consistent absence of dominant filaggrin gene defects has been reported. The detection of normal filaggrin protein content in AD skin implicates the contribution of alternative mechanisms in the pathogenesis of AD in African patients. Markedly high IgE has been described in paediatric and adult African AD. While Th2, Th22 and Th17 activation in African AD skin shares the same direction as with other populations, it has been noted that the magnitude of activation is dissimilar. Reduced Th17 cytokines have been observed in the circulation of moderate to severe paediatric AD.

Position Statement on Atopic Dermatitis in Sub-Saharan Africa: current status and roadmap.

BACKGROUND: The first International Society of Atopic Dermatitis (ISAD) global meeting dedicated to atopic dermatitis (AD) in Sub-Saharan Africa (SSA) was held in Geneva, Switzerland in April 2019. A total of 30 participants were present at the meeting, including those from 17 SSA countries, representatives of the World Health Organization (WHO), the International Foundation for Dermatology (IFD) (a committee of the International League of Dermatological Societies, ILDS www.ilds.org), the Fondation pour la Dermatite Atopique, as well as specialists in telemedicine, artificial intelligence and therapeutic patient education (TPE). RESULTS: AD is one of the most prevalent chronic inflammatory skin diseases in SSA. Besides neglected tropical diseases (NTDs) with a dermatological presentation, AD requires closer attention from the WHO and national Departments of Health. CONCLUSIONS: A roadmap has been defined with top priorities such as access to essential medicines and devices for AD care, in particular emollients, better education of primary healthcare workers for adequate triage (e.g. better educational materials for skin diseases in pigmented skin generally and AD in particular, especially targeted to Africa), involvement of traditional healers and to a certain extent also patient education, bearing in mind the barriers to effective healthcare faced in SSA countries such as travel distances to health facilities, limited resources and the lack of dermatological expertise. In addition, several initiatives concerning AD research in SSA were discussed and should be implemented in close collaboration with the WHO and assessed at follow-up meetings, in particular, at the next ISAD meeting in Seoul, South Korea and African Society of Dermatology and Venereology (ASDV) meeting in Nairobi, Kenya, both in 2020.

Affordable moisturisers are effective in atopic eczema: A randomised controlled trial.

BACKGROUND: Many patients depend on moisturisers issued by public health services in the management of atopic dermatitis (AD). METHODS: In a randomised controlled trial of patients with mild to moderate AD, aged 1-12 years, study 1 compared aqueous cream v. liquid paraffin (fragrance-free baby oil) as a soap substitute, all patients using emulsifying ointment as moisturiser, and study 2 compared four moisturisers, emulsifying ointment, cetomacrogol, white petroleum jelly and glycerine/petroleum (proportion 1:2; 'the 1:2 moisturiser'), all using fragrance-free baby oil as soap substitute. Assessments were one quality of life and three AD severity scores, at baseline and weeks 4, 8 and 12. Differences were compared using repeated measures of analysis of variance. RESULTS: In both studies (120 children randomised, 20 in each group of the two trials) disease severity scores declined with time. The only significant difference was in one AD severity score (SCORing Atopic Dermatitis) in study 1, both at baseline and over time (p=0.042 and p=0.022). The groups did not differ with regard to topical steroid use or side-effects. Itching from baby oil applied as soap was reported by four patients in the two studies, the petroleum jelly group had more dropouts than the 1:2 moisturiser group, although this was not statistically significant, and 110 patients (91.7%) completed the trial. CONCLUSIONS: The small sample limits generalisability, but the duration was longer than in most AD moisturiser studies. Fragrance-free baby oil is an effective soap substitute that may be better tolerated (if irritation occurs) as a bath additive. The home-made 1:2 moisturiser may be preferable to white petroleum jelly, but both are equivalent to cetomacrogol and emulsifying ointment. Use of accessible moisturisers could reduce the cost of managing mild to moderate AD.