Psoriasis Explained
Psoriasis is a common inflammatory skin condition affecting about 2% of people in the United States. It is characterized by inflammation that causes skin cells to grow too rapidly, forming thick, scaly plaques. While psoriasis plaques can be unsightly, they are not contagious. However, the condition can significantly impact a person’s social and psychological well-being. Although psoriasis primarily affects the skin, it is a systemic disease that can affect other body parts, including the joints.
Psoriasis is believed to be caused by an immune system dysfunction that accelerates skin cell growth. In this condition, the immune system mistakenly attacks the skin, resulting in inflammation and the overproduction of skin cells. The exact cause of this immune system malfunction is unclear, but genetic and environmental factors play a role. Several factors can trigger psoriasis flare-ups, including stress, bacterial infections, certain medications, smoking, and skin injuries.
The hallmark symptom of psoriasis is the development of plaques—thick, red/pink, and with silver scales. These plaques commonly appear on the knees, elbows, lower back, and scalp and can be itchy or uncomfortable.
Sometimes, psoriasis manifests as guttate psoriasis, which appears as small, scaly, drop-shaped lesions scattered across the body. Guttate psoriasis often follows infections like strep throat. Psoriasis can also affect the nails, causing discoloration, thickening, or irregular growth. Other forms of psoriasis may affect the skin on the hands and feet or skin folds (armpits, groin/genitals, and underneath the breasts).
A lesser-known but significant aspect of psoriasis is psoriatic arthritis, which causes joint inflammation and pain. Most individuals develop skin symptoms before experiencing arthritis, but psoriatic arthritis can sometimes appear before skin plaques. Symptoms of psoriatic arthritis include swollen or tender joints, joint pain, and stiffness that gets worse in the morning but typically eases as the day progresses.
Psoriasis-related inflammation affects more than just the skin and joints. It can increase the risk of cardiovascular diseases, including heart attack and stroke, which should be considered when managing psoriasis.
Although psoriasis is a lifelong condition, numerous treatment options are available to help manage symptoms and reduce inflammation. Managing psoriasis involves treating both the visible plaques and the underlying inflammation. Avoiding triggers is also essential for managing the disease.
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Topical Therapies: Corticosteroids are the primary topical treatment for reducing inflammation and relieving itchiness. While corticosteroids can be effective, they should be used cautiously to avoid potential side effects from overuse. Creams and lotions containing salicylic or lactic acid can help soften and reduce the thickness of plaques.
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Phototherapy: Phototherapy involves using controlled ultraviolet light to reduce skin inflammation. It is often used in conjunction with other treatments and can be beneficial in managing psoriasis flare-ups.
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Systemic Therapies: Systemic therapies target the entire body, not just the skin, and are reserved for more severe cases of psoriasis, those resistant to other therapies, or those that affect the joints. These therapies work by modulating the immune system to reduce inflammation. Biologic agents target specific inflammatory pathways in the body that are the primary drivers of the inflammation that causes psoriasis. Research has continually improved these biological treatments over the past decades, making them safer and more effective.
Treatment Options
Psoriasis is a chronic, waxing and waning skin condition in which skin cells grow too quickly, leading to thickened, red, scaly plaques.. It is considered an immune-mediated (autoimmune/inflammatory) disease, involving the interaction of genetics, immune system activity, and environmental triggers. Common sites include elbows, knees, scalp, lower back, and sometimes in skin folds. Psoriasis may also be associated with psoriatic arthritis (joint inflammation), as well as other comorbidities (e.g. metabolic syndrome, cardiovascular risk) in some patients. Because of its chronic nature, psoriasis often requires long-term disease management.
The primary aims when treating psoriasis are:
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Reduce skin inflammation and slow the overproduction of skin cells.
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Clear or reduce plaques/squamation (the scaly surface) to improve appearance, reduce itching or discomfort, and restore normal skin.
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Maintain remission and prevent flare-ups.
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Minimize side effects and risks of therapy.
Given the range of disease severity, a step-wise approach to treatments is often taken, starting with milder options and escalating if needed.
Therapies for psoriasis generally fall into these main categories: topical, phototherapy, systemic (oral or injected), and lifestyle / adjunctive measures.
Topical Treatments
For mild psoriasis (small plaques, limited body area), topical therapies are first-line. Common topical options include:
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Corticosteroids (steroids)
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Non-steroidal alternatives (calcineurin inhibitors, PDE4 inhibitor, aryl hydrocarbon receptor agonist, vitamin D analogue, retinoids, and keratolytics)
Topical therapy is typically safe, but overuse (especially of high potency steroids) may lead to skin thinning, irritation, or systemic absorption.
If topical therapy alone is insufficient, or disease is more widespread, additional treatments are considered.
Phototherapy
When topical treatments don’t suffice, light therapy (particularly narrowband UVB) is commonly considered a next step. This treatment can be highly effective and very safe, but the requirement of multiple weekly sessions in an office is burdensome and not possible for most patients.
Systemic Therapies (Non-targeted)
For moderate to severe psoriasis (large area, resistant to topicals/phototherapy, or associated joint disease), systemic therapies are used. Prior to the advent of biologics and other targeted therapies over the past two decades, systemic agents were broadly immunosuppressive and had the potential for significant side effects, requiring careful monitoring of blood tests. Medications that were once commonplace for the treatment of psoriasis, such as methotrexate, cyclosporine, and acitretin, are rarely used today.
Biologic and Targeted Therapies
The most significant advances in psoriasis treatment have come from biologic and targeted small molecule therapies, which work in a much more targeted action on the specific immune pathways that drive psoriasis.
Biologics (Injectable)
Biologics are proteins (often monoclonal antibodies) that block specific immune molecules (cytokines) or cell-surface receptors. These medications are injected into the skin every few weeks to months. They can be divided based on molecules that they target:
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TNF-α inhibitors (etanercept, adalimumab, infliximab) were the first biologic class approved for psoriasis.
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IL-12 / IL-23 inhibitor (ustekinumab)
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IL-17 inhibitors (secukinumab, ixekizumab, brodalumab, bimekizumab)
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IL-23 inhibitors (e.g. guselkumab, risankizumab, tildrakizumab)
These biologics often achieve very high levels of skin clearance, with many patients even having complete clearance of their psoriasis.
Small Molecule Inhibitors (Oral)
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PDE4 inhibitor (apremilast)
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TYK2 inhibitor (deucravacitinib)
Which treatment is appropriate depends on:
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Severity and extent of disease: mild, moderate, or severe (often judged by body surface area, involvement of sensitive sites, symptoms)
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Location of plaques: some areas (face, genitals, nails) require gentler approaches or combinations.
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Patient factors: age, comorbid medical conditions (liver disease, kidney disease, infections), pregnancy plans, preference for oral vs injectable, monitoring capacity.
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Prior treatments and responses: switching therapies is common.
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Cost, access, insurance coverage: unfortunately, insurance coverage can sometimes dictate choices given that the newer medications often come with very high price tags
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Monitoring and safety considerations: immunosuppression risks, lab monitoring, screening for infections (e.g. tuberculosis, hepatitis) before biologics.
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Dr. Michael Tee
Clinical Director & Founder
Dr. Michael Tee focuses on helping patients manage a comprehensive range of skin conditions that can significantly impact daily comfort and confidence. He works extensively with patients experiencing skin changes during pregnancy, helping them navigate the complex dermatological shifts that occur during this important time. His practice also centers on mole evaluation and management, including atypical moles that require careful monitoring and assessment. Dr. Tee regularly treats patients dealing with acne, seborrheic dermatitis, and various forms of eczema, conditions that can affect both appearance and quality of life.