What You Need to Know About Plaque Psoriasis This Year

Summary and Overview

Plaque psoriasis is a chronic immune-mediated skin disorder marked by erythematous, sharply demarcated plaques with silvery-white scales, typically on extensor surfaces and nails. It affects 1% to 3% of the global population and is linked to systemic comorbidities like psoriatic arthritis, cardiovascular disease, metabolic syndrome, and depression. The disease involves genetic factors, especially the HLA-C*06:02 allele, and immune dysregulation centered on the IL-23/Th17 axis. Environmental triggers include infections, stress, and trauma. Treatments range from topical agents and phototherapy to systemic biologics targeting cytokines such as IL-17 and IL-23, with emerging oral therapies including TYK2 inhibitors. Patients often face itching, pain, psychological distress, and severe forms like erythrodermic psoriasis that require urgent care. Treatment decisions consider factors like BMI and long-term management challenges. Ongoing research focuses on optimizing therapies and understanding genetic susceptibility to improve outcomes.

Clinical Presentation and Diagnosis

Plaque psoriasis, the most common psoriasis type, presents as raised, red plaques with silvery scales, commonly on elbows, knees, scalp, torso, and nails. Symptoms include itching and pain, affecting daily life and self-image. Variants include palmoplantar, pustular, guttate, erythrodermic, and inverse psoriasis, with erythrodermic psoriasis being potentially life-threatening. Diagnosis is primarily clinical, based on lesion appearance and history, with differential diagnoses including eczema and fungal infections. Genetic markers like HLA-C*06:02 aid understanding but are not routine for diagnosis.

Pathophysiology

Plaque psoriasis results from genetic susceptibility and immune system dysregulation. The PSORS1 locus, especially HLA-C*06:02, strongly influences risk. Immune activation involves antimicrobial peptides triggering dendritic cells to release cytokines (TNF, IL-6), recruiting neutrophils and Th17 cells. The IL-23/Th17/IL-17A pathway drives keratinocyte proliferation and inflammation, sustaining plaques. IL-36 cytokines further enhance inflammation. Systemic inflammation links to metabolic syndrome and comorbidities. The JAK-STAT pathway, particularly TYK2, is a target for new oral treatments.

Treatment

Treatment depends on severity and includes topical agents, phototherapy, and systemic therapies. Topicals like corticosteroids, vitamin D analogues, calcineurin inhibitors, and newer agents such as roflumilast cream and tapinarof are first-line for mild to moderate disease. UVB phototherapy is effective for moderate-to-severe cases and often combined with topicals. Systemic options include oral PDE4 inhibitors like apremilast and biologics targeting TNF-α, IL-17, and IL-12/23. The recent biologic bimekizumab blocks IL-17A and IL-17F, offering enhanced efficacy. Treatment choice may be influenced by patient factors such as BMI. Research continues on oral agents combining biologic efficacy with convenience.

Complications and Associated Conditions

Plaque psoriasis is linked to metabolic syndrome, psoriatic arthritis, and spondyloarthropathy. Mental health issues, including depression, are common, though biologic treatments do not increase psychiatric risks. Severe erythrodermic flares require urgent care due to systemic symptoms. Cardiovascular disease risk is elevated, with various markers used for assessment. Effective psoriasis management may improve associated comorbidities.

Epidemiology and Research Advances

Psoriasis affects about 0.59% of adults globally, with prevalence varying by region, age, and ethnicity. Genetic studies have identified numerous susceptibility loci, though psoriatic arthritis genetics remain less defined. Environmental triggers like infections and trauma influence disease course. Advances in molecular understanding, especially of immune pathways and the JAK-STAT system, are guiding novel treatments. Research includes new oral PDE4 inhibitors, biologics, and innovative delivery methods such as microneedle patches.

Long-Term Outcomes and Patient Support

Long-term management balances efficacy and safety, using tools like PASI and DLQI for monitoring. New topical agents like roflumilast cream show sustained safety and effectiveness. Oral TYK2 inhibitors have promising efficacy with favorable safety profiles. Biologics remain effective but have challenges including administration routes and cost. Patient support through education, specialist care, clinical trial access, and support groups is vital to address physical and psychological impacts and improve quality of life.

The content is provided by Sierra Knightley, Scopewires