Understanding the Intricate Pathophysiology of Psoriasis and Related Skin Disorders

Psoriasis is a chronic inflammatory condition that is polygenic and multisystemic, impacting approximately 2-3% of the global population. The onset of this disease is influenced by an intricate interplay of genetic and environmental factors, predisposing individuals to the psoriasis phenotype. The complex pathogenesis of psoriasis contains certain key aspects found in other autoinflammatory and autoimmune dermatological diseases. Among these, vitiligo, alopecia areata, hidradenitis suppurativa, vitiligo, connective tissue diseases, bullous dermatoses, and atopic dermatitis are conditions that share overlapping immune system dysfunction, making their relationship with psoriasis particularly significant. For our research, we explored various terms including "shared", "concomitant", "coincident", "overlap", "coexist", and "concurrent", in relation to conditions such as "psoriasis", "alopecia areata", "hidradenitis suppurativa", "atopic dermatitis", "vitiligo", "bullous pemphigoid", "pemphigus vulgaris", "lupus erythematosus", "dermatomyositis", and "systemic sclerosis." Additionally, we used specific search queries like "atopic dermatitis overlapping syndrome" and "psoriasis and vitiligo concomitant disease" in the PubMed and Web of Science databases. While distinct in their clinical presentation, the skin diseases related to psoriasis may become associated, complicating diagnosis and treatment. In this narrative review, the complex pathophysiology of psoriasis is described, along with its close relationship to other skin conditions. This review provides an exhaustive description of both immunological and non-immunological pathways contributing to their development. Understanding the intricate interconnection between psoriasis and these conditions is of interest to scientists in developing novel research directions and to clinicians in providing holistic care, as managing one condition may influence the course of others.