A systematic review and meta-analysis of the regional and age-related differences in atopic dermatitis clinical characteristics

BACKGROUND

Previous studies found conflicting results about the commonality of different atopic dermatitis (AD) signs and symptoms.

OBJECTIVE

To determine the prevalences of AD characteristics and differences by region and age.

METHODS

A systematic review was performed of all published studies in MEDLINE, EMBASE, SCOPUS, LILACS, Cochrane, China National Knowledge Infrastructure, Taiwan Electronic Periodical Services, and CiNii that analyzed the proportion of AD characteristics. Two reviewers performed a review study titles and/or abstracts and data abstraction.

RESULTS

In all, 101 studies reported proportion of AD features with sufficient data for meta-analysis. The most prevalent AD features were pruritus, lichenification, and xerosis. There were differences in AD characteristics by study region. Flexural involvement was less commonly reported in India, the Americas, and Iran. Studies from East Asian reported more erythroderma and truncal, extensor, scalp, and auricular involvement. Studies from Southeast Asia reported more exudative eczema, truncal involvement, lichenification, and prurigo nodularis. Studies from Iran reported more head, face, and neck involvement; pityriasis alba; and xerosis. Studies from Africa reported more papular lichenoid lesions, palmar hyperlinearity, ichthyosis, and orbital darkening.

LIMITATIONS

Heterogeneity between studies and limited reporting of certain AD clinical characteristics.

CONCLUSIONS

AD characteristics are heterogeneous and vary by region and age.

A systematic review and meta-analysis of the prevalence and phenotype of adult-onset atopic dermatitis

BACKGROUND

Previous studies found conflicting results about whether atopic dermatitis (AD) begins in adulthood.

OBJECTIVE

To determine rates, predictors, and phenotypic differences of adult-onset AD.

METHODS

A systematic review was performed with all published observational studies in Medline, Embase, GREAT (Global Resource of EczemA Trials), LILACS (Latin American and Caribbean Health Sciences Literature), Cochrane Library, and Scopus that analyzed the age of AD onset beyond 10 years of age. At least two reviewers performed study title, abstract review, and data extraction. Pooled meta-analysis of the proportion of adult-onset AD was performed by using random-effects weighting (I² = 99.3%).

RESULTS

Overall, 25 studies met inclusion criteria. Seventeen studies reported age of AD onset as after 16 years of age and had sufficient data for meta-analysis. The pooled proportion (95% confidence interval) of adult-onset AD was 26.1% (16.5%-37.2%). Similar results were found in sensitivity analyses by AD diagnostic method, study region, and sex. Phenotypic differences were observed across studies for adult-onset and child-onset AD, including higher rates of foot dermatitis and personal history of atopy but lower rates of flexural lesions and other signs and symptoms.

LIMITATIONS

Characteristics of adult-onset versus child-onset AD were not commonly reported.

CONCLUSION

AD is not only a disease of childhood; 1 in 4 adults with AD report adult-onset disease, which has distinct clinical characteristics as compared to child-onset AD.