Psoriasis is an autoimmune condition that affects the skin and other systems of the body. Some medications target psoriasis at a systemic level, while others primarily treat the skin symptoms.

Here, Dr. Joshua Zeichner explains the differences between systemic treatments and topical treatments, including examples of specific medications and potential side effects.

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There are a number of topical steroids available to manage symptoms of psoriasis.

Systemic treatments are medications that address psoriasis from the inside out. They treat the entire body rather than a specific area. A person may take these by mouth or in the form of an injection.

Doctors tend to use systemic treatments when people have more severe psoriasis or other related conditions, such as psoriatic arthritis.

They may prescribe systemic treatments when the affected skin surface is too large for treatment with topical medications or if psoriasis plaques do not improve with topical treatments.

Systemic treatments may be more effective than topical treatments. They also carry more potential side effects, and some lower a person’s immunity. Although the risk is low, in some cases, these treatments may increase a person’s chance of developing an infection or cancer.

Topical medications treat the skin and do not address internal issues such as arthritis. They apply directly to the skin and include:

  • creams
  • lotions
  • foams
  • solutions
  • gels
  • tapes
  • ointments

Topicals are excellent options for people with localized disease, such as when a person has psoriasis plaques on the elbows or knees. They only treat the areas of skin a person applies them to.

They do not have as many side effects as systemic medications. However, they may not be as effective or practical in more severe cases of psoriasis.

Systemic treatments include traditional immune-suppressing medications as well as newer biologic agents.

Traditional systemic medications

These laboratory-made small molecules have relatively nonspecific effects in the body. Examples with Food and Drug Administration (FDA) approval for treating psoriasis include:

  • Methotrexate and cyclosporine: These decrease immune system activity to block inflammation.
  • Acitretin: Rather than lowering immune activity, this vitamin A derivative normalizes skin cell turnover to prevent thick psoriasis plaques from developing.
  • Apremilast (Otezla): This is a small-molecule drug that seems to have more of an anti-inflammatory effect than an immunosuppressive effect.
  • JAK inhibitors: These are fast-working medications that target inflammation. Examples include updadacitinib (Rinvoq), tofacitinib (Xeljanz), and deucravacitinib (Sotyktu).

Biologic treatments

Laboratories produce these medications using living organisms, such as bacteria. They are more specific than traditional drugs and do not generally suppress the immune system.

Four main classes of biologic medications have approval for treating psoriasis and psoriatic arthritis. How a medication works, and the part of the immune system it addresses determines the class.

The four classes are:

The broad categories for topical treatments are steroidal and nonsteroidal.

Topical steroids

These creams, ointments, and other preparations have anti-inflammatory effects on the skin to clear psoriasis plaques. They include a class of medication called a corticosteroid.

Although effective and fast-acting, topical steroids have potential side effects. For example, extended use can lead to:

  • thinning of the skin
  • dilated blood vessels
  • stretch marks
  • pimples

Doctors typically limit the use of topical steroids to no more than two consecutive weeks for most medications. After that initial treatment, they will usually recommend intermittent use of topical steroids for maintenance.

Nonsteroidal topical treatments

These medications use ingredients other than corticosteroids. They include:

  • Vitamin D analogs: These seem to normalize skin cell turnover and calm inflammation. Examples include calcipotriene and calcitriol.
  • Topical retinoids: These regulate the cell proliferation, or cell division, that contributes to the formation of psoriasis plaques. Tazarotene is one such example.
  • Calcineurin inhibitors: The FDA does not currently approve these for psoriasis treatment, but many dermatologists use them off-label to treat this condition. Examples include tacrolimus ointment and pimecrolimus cream.
  • Anthralin: Anthralin is an artificial version of a natural substance from goa powder that slows skill cell growth. Doctors may recommend it to treat scalp psoriasis.
  • Tapinarof (VTAMA): This treatment targets proteins in the immune system to clear plaque psoriasis.
  • Roflumilast (ZORYVE): This is an anti-inflammatory treatment that may be effective against inverse psoriasis.

Nonsteroidal topicals do not tend to be as potent or fast-acting as steroidal creams, but they are safe to use for extended periods. They are commonly part of a maintenance regimen, along with topical steroids.

People with moderate-to-severe psoriasis commonly use systemic and topical treatments together. Although systemic medications are effective, people may achieve less skin clearance than they would like.

For example, psoriasis plaques may be much better but not completely clear, or some plaques may not respond at all. In these cases, people can use directed topical treatments alongside systemic treatments.

A doctor may recommend systemic treatments in the following instances:

  • psoriasis is severe
  • psoriasis affects a large body surface
  • previous topicals were not effective
  • there are systemic manifestations, such as arthritis

Topical treatments typically treat psoriasis plaques in specific areas, such as the elbows or knees. They do not cause as many side effects as systemic treatments, but they may not be as effective in more severe cases of psoriasis.

Systemic treatments have potential side effects for the entire body, including a risk of infections or cancer. For example, cyclosporine can cause high blood pressure and kidney injury, and methotrexate can cause liver injury.

Healthcare professionals will routinely monitor people taking these medication to ensure these side effects do not occur.

Certain medications may also cause nausea or skin reactions at the site of injection.

Topical treatments are associated with side effects in the specific treated areas. These side effects include:

  • thinning of the skin
  • stretch marks
  • dilated blood vessels
  • pimples

Dermatologists regularly use skin exams and blood work to monitor people taking systemic medications. They may recommend temporarily stopping a systemic medication if it causes certain side effects.

For people using topical medications, dermatologists regularly evaluate the skin for side effects. A person should stop using a topical right away if it causes thinning of the skin.

Psoriasis skin lesions are treatable regardless of how long they are present. Severe plaques commonly heal with dark or red spots known as post-inflammatory pigmentation or post-inflammatory erythema, but this will improve on its own over weeks to months.

It is important to treat psoriatic arthritis at its earliest stages to prevent complications. Joint destruction due to psoriatic arthritis is permanent.

Psoriasis is associated with metabolic syndrome, including heart disease and diabetes. Eating a well-balanced diet rich in fresh fish, colorful fruit, and green leafy vegetables provides the body with the vitamins and nutrients it needs to function at its best.

A low fat diet is important for people who have high cholesterol. A diet low in sugary food benefits people who have diabetes or prediabetes. Doctors may recommend weight loss for people with overweight or obesity.

Finally, smoking can worsen psoriasis. Quitting smoking can improve psoriasis symptoms.

A flood of new topical and systemic medications can treat psoriasis. However, visiting a dermatologist for proper diagnosis and treatment is important.

The future may bring genetic testing options to understand the specific causes of psoriasis and determine effective personalized treatments.

People with psoriasis should speak with a doctor about their personal preferences. It is important to navigate psoriasis treatments together.

A person should consider getting another opinion if a doctor only prescribes topical medications that do not work or if a doctor does not use biologic medications.

Patients are consumers of healthcare. It is important for people to seek out different opinions for care options and be their own advocates.

Dr. Joshua Zeichner is a board certified dermatologist on full-time faculty at the Mount Sinai Hospital in New York City, NY. He received his medical degree from the Johns Hopkins University School of Medicine, followed by residency and fellowship in Dermatology at the Mount Sinai Hospital Department of Dermatology. He is a fellow of the American Academy of Dermatology.