What are the laboratory findings for Psoriasis?

From the Guidelines

Laboratory tests for psoriasis should include a complete blood count (CBC), comprehensive metabolic panel (CMP), lipid panel, and inflammatory markers like C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) to establish baseline health status and monitor for comorbidities. When managing psoriasis, particularly in patients starting systemic therapies, it is essential to consider the potential risks and benefits of treatment. According to the guidelines of care for the management of psoriasis and psoriatic arthritis 1, patients should undergo baseline testing including a chemistry screen with liver function tests, complete blood cell count including platelet count, a hepatitis panel, and tuberculosis (TB) testing. For patients on methotrexate, monitoring should include complete blood count, hepatic transaminases, and creatinine, with laboratory tests performed at least 4 days after dosing to avoid making dosage adjustments based on transient elevations of hepatic transaminases 1. Some key points to consider in laboratory testing for psoriasis include:

• Baseline testing for patients starting systemic therapies
• Regular monitoring for patients on systemic medications, including CBC and CMP every 3-6 months
• Consideration of HLA-B27 testing in cases with joint symptoms to evaluate for psoriatic arthritis
• Monitoring for latent infections such as tuberculosis, hepatitis, or HIV before therapy based on individual circumstances and local epidemiology 1. Regular monitoring and baseline testing are crucial to ensure safe medication use and detect potential complications early in patients with psoriasis.

From the Research

Psoriasis Lab

• Psoriasis is a chronic complex multisystem, inflammatory, skin disorder that causes vasodilatation and hyperproliferation of keratinocytes, whose clinical expression includes a thickened, erythematous skin, often covered with silver gray scales 2.
• The histopathology of psoriasis is easily recognizable when the disease involves the typical sites such as the extensor surfaces, and although a biopsy is rarely required in case of classic psoriasis, in atypical and controversial conditions, histopathological examination remains the main diagnostic tool that can help in differentiating psoriasis from other dermatoses 2.

Clinical Presentation and Diagnosis

• Plaque psoriasis is the most common variant of psoriasis, and patients with psoriasis experience substantial morbidity and increased rates of inflammatory arthritis, cardiometabolic diseases, and mental health disorders 3.
• Diagnosis of plaque psoriasis is dependent primarily on characteristic physical findings and history, and given the varied clinical presentations of psoriasis and its mimicry to other papulosquamous skin diseases, it may be difficult for nondermatologists to diagnose psoriasis 4.
• Currently, no diagnostic criteria for plaque psoriasis have been validated in clinical studies, but diagnostic guidelines for the nondermatologist can aid them in recognizing psoriasis 4.

Treatment and Comorbidities

• Topical agents remain the mainstay of treatment for patients with mild psoriasis, and they include topical corticosteroids, vitamin D analogues, calcineurin inhibitors, and keratolytics 3.
• Biologics are an option for first-line treatment of moderate to severe plaque psoriasis because of their efficacy in treating it and acceptable safety profiles, and inhibitors to tumor necrosis factor α (TNF-α) include etanercept, adalimumab, certolizumab, and infliximab 3.
• Psoriasis is associated with multiple comorbidities, including psoriatic arthritis, cardiometabolic diseases, and depression, and liver test abnormalities are more prevalent in patients with severe psoriasis, especially those with plaque-type psoriasis (PV) and pustular psoriasis (PP) 5.
• Systemic therapy with secukinumab, ixekizumab, adalimumab, or apremilast does not present a general risk, but rather an opportunity for patients with psoriasis with elevated liver function tests (LFTs) at baseline, as LFTs decreased significantly over time in patients with initially elevated LFTs 6.