Beyond the dichotomy: understanding the overlap between atopic dermatitis and psoriasis

Area of Science:

• Dermatology and immunology
• Cutaneous inflammatory diseases
• Microbiome research

Background:

• Atopic dermatitis (AD) and psoriasis are traditionally viewed as separate inflammatory skin diseases.
• Emerging evidence reveals significant overlaps in immunological, metabolic, and microbiome profiles.
• This challenges the conventional view of distinct pathogenic mechanisms.

Purpose of the Study:

• To comprehensively review the complex relationship between psoriasis and atopic dermatitis.
• To emphasize shared and distinct pathogenic mechanisms, including immunological, metabolic, and microbial factors.
• To discuss the disease spectrum hypothesis and nomenclature for overlapping conditions.

Main Methods:

• Literature review synthesizing current evidence on psoriasis and atopic dermatitis.
• Analysis of immunological networks, metabolic pathways, and microbiome characteristics.
• Evaluation of clinical, histopathological, and molecular diagnostic advances.

Main Results:

• Significant overlap exists in immunological pathways, metabolic features, and microbiome characteristics between AD and psoriasis.
• The review supports a disease spectrum hypothesis, suggesting a continuum rather than strict separation.
• Advances in molecular diagnostics aid in differentiating these complex conditions.

Conclusions:

• Psoriasis and atopic dermatitis exhibit considerable overlap, necessitating a revised understanding of their pathogenesis.
• Standardized diagnostic criteria and tailored therapeutic strategies are crucial for managing these overlapping inflammatory skin conditions.
• Further research is needed to elucidate the complex interplay and guide clinical decision-making.