Overlap Phenotype Between Psoriasis and Atopic Dermatitis

According to a study published in the Journal of Investigative Dermatology, within the clinical overlap phenotype between psoriasis and atopic dermatitis (AD), psoriasis has the dominant molecular features.

Researchers enrolled 41 patients initially diagnosed with either psoriasis or AD and re-stratified them into 3 groups: classic psoriasis (n=11), classic AD (n=13), and the overlap phenotype between psoriasis and AD (n=17). Researchers compared the gene expression profiles of lesional and non-lesional skin biopsy tissues and the proteomic profiles of blood samples among these groups.

Findings showed that global mRNA expression, T-cell subset cytokine expression in the skin, and protein biomarker levels in the blood of the overlap phenotype were consistent with psoriasis profiles and distinct from AD profiles. Unsupervised k-means clustering analysis indicated that the optimal number of distinct clusters for the total population of the 3 groups was 2, distinguishing psoriasis and AD based on gene expression.

The study concluded that the clinical overlap phenotype between psoriasis and AD predominantly exhibits molecular features of psoriasis. Genomic biomarkers can effectively differentiate psoriasis and AD at the molecular level in patients with a spectrum of these conditions. This suggests that the overlap phenotype should be treated with strategies tailored more toward psoriasis rather than AD, based on its dominant molecular characteristics.

Reference
Kim JE, Lee J, Huh YJ, et al. Genomic profiling of the overlap phenotype between psoriasis and atopic dermatitis. J Invest Dermatol. 2024;144(1):43-52.e6. doi:10.1016/j.jid.2023.06.194