Psoriasis is treated with a range of options that span from creams applied directly to the skin to injectable medications that calm the immune system from within. The right approach depends largely on how much skin is affected and how well you respond to initial treatments. Most people start with topical therapies, then move to light therapy, oral medications, or biologics if the disease is more widespread or stubborn.
Topical Treatments: The Starting Point
For mild to moderate psoriasis, topical corticosteroids are the standard first-line treatment. These creams and ointments reduce inflammation and slow the rapid skin cell turnover that causes plaques. They come in a range of potencies: low-potency versions are used on sensitive areas like the face and skin folds, while high-potency formulas are reserved for thick plaques on the palms, soles, and other tough spots.
The catch with topical steroids is that long-term use causes skin thinning, sometimes permanently. Even three days of a potent steroid can begin affecting the skin’s structure. Short-term thinning can reverse itself, but prolonged use may cause stretch marks, visible blood vessels, and increased fragility that don’t go away. That’s why dermatologists typically limit high-potency steroids to short courses and look for alternatives when treatment needs to continue.
Vitamin D-based creams, particularly calcipotriene, are one of those alternatives. Endorsed by both the American Academy of Dermatology and the National Psoriasis Foundation, these work by slowing the overproduction of skin cells and dialing down the immune activity driving psoriatic plaques. They’re often used alongside steroids or rotated with them to reduce steroid exposure over time. Newer topical options also exist, including phosphodiesterase-4 inhibitors, which offer steroid-free anti-inflammatory effects, though they tend to be more expensive.
Scalp and Hard-to-Treat Areas
Psoriasis on the scalp, hands, and feet often requires special delivery methods. For the scalp, prescription shampoos containing clobetasol propionate can penetrate through hair to reach the skin. Coal tar shampoos are available over the counter and help with flaking and itching. When plaques are especially thick, products with salicylic acid help soften them so other medications can actually get through.
Calcipotriene works on the scalp too. Most people apply it at bedtime and cover the scalp with a shower cap overnight to help it penetrate thick patches. Tazarotene, a retinoid, follows a similar routine: a thin layer at night, then washed off in the morning shower. For stubborn spots, excimer laser therapy can target small areas of the scalp, hands, or feet with concentrated UV light using a device that resembles a blow dryer.
Phototherapy for Moderate to Severe Psoriasis
When topical treatments aren’t enough, phototherapy uses specific wavelengths of ultraviolet light to slow skin cell growth and reduce inflammation. Narrowband UVB is the most common form. A typical course involves three sessions per week, with most people needing 20 to 36 sessions to see significant clearing. Each appointment lasts about 15 minutes, with at least 24 hours between sessions. Once the skin clears, the frequency drops to once a week for maintenance.
Phototherapy works well for people with widespread plaques who want to avoid the side effects of systemic medications. The main downsides are the time commitment of regular clinic visits and the cumulative UV exposure over months and years of treatment.
Oral Medications for Widespread Disease
When psoriasis covers a large portion of the body or significantly affects quality of life, oral medications offer whole-body treatment. Methotrexate has been a mainstay for decades, working as both an anti-inflammatory and a brake on rapid cell growth. Cyclosporine suppresses the overactive immune response and can produce fast results, but it’s generally used for shorter periods due to effects on the kidneys and blood pressure. Acitretin, a retinoid, slows skin cell production and is sometimes combined with other treatments.
Apremilast works differently, blocking a specific enzyme involved in the inflammatory process. It’s taken as a daily pill and has a milder side effect profile than the older options, though it’s also generally less potent. When one oral medication alone isn’t enough, dermatologists sometimes combine them. Cyclosporine, acitretin, or apremilast can be added to methotrexate in patients who haven’t responded adequately to a single drug.
The newest oral option is deucravacitinib, approved by the FDA in September 2022. It selectively blocks a specific immune signaling protein called TYK2, which drives several of the inflammatory pathways behind psoriasis. What makes it notable is its precision: unlike older drugs in the same general family (JAK inhibitors), which carry boxed safety warnings because they affect multiple immune pathways, deucravacitinib targets only TYK2 and currently carries no boxed warnings. It’s classified as a first-in-class medication for this reason.
Biologic Injections
Biologics are the most targeted treatments available. They’re proteins delivered by injection or infusion that block specific molecules in the immune system responsible for driving psoriasis. There are currently eleven FDA-approved biologics for psoriasis, grouped by the immune protein they target:
- TNF blockers (four approved drugs) target tumor necrosis factor, one of the first inflammatory signals identified in psoriasis.
- IL-12/23 blocker (one approved drug) targets a pair of immune messengers that activate the T cells responsible for psoriatic inflammation.
- IL-17 blockers (three approved drugs) target interleukin-17, a protein directly involved in triggering the rapid skin cell production that forms plaques.
- IL-23 blockers (three approved drugs) target interleukin-23, which sits upstream in the inflammatory chain and orchestrates much of the immune dysfunction in psoriasis.
The newer classes, particularly IL-23 and IL-17 blockers, have shown the highest clearance rates. In a large observational study of over 600 patients, 83% achieved at least 90% skin clearance on biologic therapy, and 45% achieved complete clearance. IL-23 blockers showed significantly better results than TNF blockers or the IL-12/23 blocker, with IL-17 blockers close behind. Many biologics are dosed infrequently after the initial loading period, with some IL-23 blockers requiring injections only every two to three months.
How Weight and Diet Affect Outcomes
Carrying excess weight makes psoriasis harder to treat and increases disease severity. The strongest dietary evidence supports calorie reduction in people with psoriasis who are overweight or obese. A meta-analysis of six randomized controlled trials found that patients on a reduced-calorie diet alongside their psoriasis treatment saw meaningfully greater improvement in their skin than those on a regular diet.
The results can be dramatic. In one study of 37 patients who had never been on psoriasis medication, a 10-week weight loss program cut disease severity scores roughly in half. A follow-up study found a similar 50% reduction in just four weeks. Even observational data from patients fasting during Ramadan showed a significant drop in psoriasis severity after one month.
The Mediterranean diet has shown a clear inverse relationship with psoriasis activity: the more closely people follow it, the less severe their symptoms tend to be. A ketogenic diet showed promise in a crossover trial, where it not only reduced skin symptoms but also lowered levels of the same inflammatory proteins (IL-6, IL-17, IL-23) that biologic drugs are designed to block. For people who test positive for markers of gluten sensitivity, a gluten-free diet is also recommended. None of these dietary approaches replace medical treatment, but they can meaningfully improve how well treatments work.