A growing number of injectable drugs are available for treating psoriasis, a condition in which a person develops an excess of skin cells on their body, leading to skin changes and other symptoms.

Scientists do not know exactly what causes psoriasis, but they believe it occurs when the immune system attacks healthy cells, causing skin cells to grow too fast.

Psoriasis is a chronic condition. There is currently no cure, but treatment can help control symptoms, and newer treatments are proving more effective than previous ones for some types of psoriasis.

People have traditionally used over-the-counter (OTC) therapies, lifestyle remedies, and some prescription drugs to treat psoriasis, but doctors may now prescribe injectable drugs known as biologics when symptoms are moderate to severe.

In recent years, the Food and Drug Administration (FDA) has approved a number of new drugs, and there is hope that these can significantly improve quality of life for people with psoriasis.

As with all medications, some side effects are possible. A doctor will discuss these with the individual before prescribing a drug.

Most of the injectable medications for treating psoriasis are known as biologic drugs, or “biologics.”

These drugs target the immune system. Different biologics work in different ways, but they all target cytokines, a type of protein that the immune system produces.

In expected circumstances, cytokines play a role in protecting the body from harmful or unwanted substances. When the body produces extra cytokines as part of the immune response, inflammation occurs. Normally this passes, but in some cases, such as psoriasis, the immune response persists, and the inflammation continues.

Scientists make biologics from living cells that they grow in a laboratory. They harvest special types of proteins from these cells and use these proteins in medications. These medications aim to resolve the symptoms of psoriasis by reducing the extra immune activity that psoriasis involves.

The FDA has approved several biologic medications to treat psoriasis.

Some of these medications can target special T-cells in the immune system. Others can stop proteins in the immune system from growing.

Doctors only usually prescribe these medicines when a person’s psoriasis is moderate to severe and other treatments have not worked.

Interleukin-12 and -23

Interleukin-12 (IL-12) and interleukin-23 (IL-23) are two of the proteins that the body produces as part of the immune response. They are linked to psoriasis symptoms. Blocking the actions of these proteins may reduce psoriasis inflammation.

Ustekinumab (Stelara) is an IL-12 blocker that has FDA approval to treat various types of psoriasis. It binds to both IL-12 and IL-23 and reduces their impact in the body.

The FDA has also approved the following IL-23 blockers to treat plaque and other types of psoriasis:

  • guselkumab (Tremfya)
  • tildrakizumab (Ilumya)
  • risankizumab (Skyrizi)

Interleukin-17A

IL-17A is another protein that appears to trigger an immune system reaction that can lead to psoriasis. Blocking this process may also prevent this reaction.

Examples of FDA-approved psoriasis injections that block IL-17A include:

  • secukinumab (Cosentyx)
  • ixekizumab (Taltz)
  • brodalumab (Siliq)

Tumor necrosis factor-alpha blockers

Proteins known as cytokines can trigger inflammation in the body. Tumor necrosis factor-alpha (TNF-alpha) is one type of cytokine.

When a person has a condition such as rheumatoid arthritis or psoriasis, the body produces too much TNF-alpha. Blocking TNF-alpha production should, in theory, prevent certain psoriasis symptoms.

The FDA has approved the following TNF-alpha blockers to treat psoriasis:

A doctor will deliver Remicade using an intravenous (IV) infusion instead of a standard injection.

A doctor should speak with the individual about the drugs available, how to use them, and the possible side effects. They will choose a drug that is appropriate for the type of psoriasis the person has.

They should also monitor the person to check for any unwanted effects, and they may suggest an alternative if one option appears to be unsuitable.

A doctor may prescribe the medication methotrexate (Trexall, Rheumatrex) to treat psoriasis. Methotrexate is a systemic drug. This means it works throughout the body. Methotrexate is not a biologic.

Instead, it is a disease-modifying anti-rheumatic drug, or DMARD. It works to suppress the immune system, but it does this in a different way than biologics.

A doctor may prescribe this drug alongside a biologic or another treatment. Each combination needs FDA approval because combining certain drugs can increase the risk of adverse effects.

Methotrexate is available either as an oral medication in pill form or as an injection.

Methotrexate can have some side effects. Drugs that reduce the action of the immune system can increase the risk of infection. Studies have shown that combining methotrexate with other drugs may increase this risk.

Originally, doctors prescribed methotrexate in larger dosages as a chemotherapy agent to treat cancer. Now, they use it to treat a number of health conditions, including psoriasis and rheumatoid arthritis.

Injectable drugs are proving effective in reducing the symptoms of moderate to severe psoriasis.

Some of them are also effective in treating psoriatic arthritis. Injections of TNF-alpha blockers may help reduce long-term joint damage in patients with psoriatic arthritis.

The frequency with which a person needs an injection can vary from twice a week to once every 3 months.

For some of these treatments, a person will need to go to the doctor’s office each time. For others, they can learn how to administer them at home.

Seeing the doctor regularly for injections may be more challenging, but it also enables the doctor to monitor symptoms and check for any adverse reactions to the drug.

Drugs that affect the immune system can have serious side effects.

They may leave a person more prone to infections, such as tuberculosis (TB). A doctor will screen an individual for TB before and during treatment.

The effect of biologic drugs on pregnancy remains unclear. For this reason, doctors rarely prescribe them for women who are pregnant or nursing.

Side effects related to psoriasis injections can range from mild to severe.

Adverse effects of biologic drugs

More common side effects include:

  • a higher risk of respiratory or urinary tract infections
  • headaches
  • flu-like symptoms, such as low energy and body aches
  • reactions at the injection site, such as redness, swelling, or discomfort

Rarer side effects include:

  • blood disorders
  • a higher risk of certain cancer types
  • an increased risk of serious nervous system disorders, including multiple sclerosis (MS), nervous system inflammation, and seizures

Adverse effects of methotrexate

Methotrexate is not a biologic drug, and it has different side effects. The most common ones are:

  • nausea
  • appetite loss
  • fatigue

Long-term treatment with methotrexate can lead to:

  • liver damage
  • changes to red and white blood cell production

A doctor should inform a person who is receiving psoriasis injections about the possible side effects and their symptoms. Anyone who experiences new or worsening symptoms after taking a drug should contact their doctor.

There are several types of psoriasis, and they may need different treatment approaches.

When prescribing a treatment, a doctor will consider:

  • the psoriasis type
  • where the symptoms are
  • how severe the symptoms are

Topical treatments

Many people use topical treatments to remedy the external symptoms of psoriasis.

Topical corticosteroids can reduce inflammation in the skin in cases of mild to moderate psoriasis.

However, long-term steroid use can lead to side effects, including an increased risk of cataracts and osteoporosis.

Other treatments include:

Moisturizers that are suitable for people with psoriasis are available for purchase online.

Additional medication options

Other oral treatments include oral corticosteroids, retinoids, and cyclosporine.

Oral corticosteroids are a systemic therapy that can improve symptoms throughout the body. It is possible that systemic steroid treatment can have adverse effects, including rebound psoriasis, or the triggering of a flare. However, a 2020 study indicates that the risk of a flare following oral steroid use is low.

Retinoids (Soriatine, acitretin) are a form of vitamin A. They are available in oral or topical form. They can help some people, but it can take several months to see the effects.

Cyclosporine is an immune suppressant that people can take as a daily pill. Some people may benefit from this. The doctor will need to monitor the person’s blood pressure and kidney health.

Apremilast (Otezla) is a DMARD that may reduce the incidence of psoriasis plaques. People can take it by mouth. In 2017, the authors of a review described it as “well tolerated.” A person using it does not need ongoing lab tests to monitor for adverse effects.

Apremilast is a phosphodiesterase-4 (PDE4) inhibitor. Research has found links between PDE4 and the inflammation that leads to psoriasis, so taking a PDE4 inhibitor may help reduce the incidence of psoriasis plaques.

Light therapy

Light therapies may help. These involve exposing the skin to a certain amount of UV light, usually in a doctor’s office.

Excess exposure to UV light can increase the risk of skin cancer, and sunlight is not as effective as prescription phototherapy, so a person should speak with their doctor about the best ways to manage light therapy.

Lifestyle changes

Psoriasis is an inflammatory skin condition. Some lifestyle choices can trigger inflammation and may worsen the symptoms of psoriasis.

Examples include:

  • stress
  • smoking
  • intense or prolonged sun exposure

These factors may not trigger symptoms in everyone with psoriasis. However, if a person tries avoiding them, they may find that their symptoms improve.

Alcohol may affect how well psoriasis medications work, so cutting out alcohol may help some people.

Home remedies

Bathing with lukewarm water may help relieve psoriasis symptoms, especially if a person adds one of the following substances to the water:

  • unscented bath oil
  • colloidal oatmeal
  • Dead Sea salts
  • Epsom salts

Applying moisturizers to the skin after taking a bath may also be beneficial.

Anyone who is receiving injectable psoriasis medication should contact their doctor if they experience signs of an infection. These may worsen quickly and be harder to treat if the person’s medication is targeting their immune system.

Symptoms of an infection include:

  • fever
  • cough
  • flu-like symptoms
  • sores that do not heal

A person should also speak with their doctor if they notice other symptoms or side effects of a medication or if their symptoms worsen. Sometimes, a biologic drug becomes less effective after a while. In these cases, a doctor may need to adjust the dosage or suggest a different medication.

What injections are used for psoriasis?

Medications for psoriasis that are delivered through injection include methotrexate and biologics. Some biologics can be taken at home once a healthcare professional instructs a person on the proper method for injections. Others must be injected by a healthcare professional or are delivered through an IV infusion.

Biologics approved by the FDA for the treatment of psoriasis include:

  • adalimumab (Humira)
  • brodalumab (Siliq)
  • certolizumab pegol (Cimzia)
  • etanercept (Enbrel)
  • golimumab (Simponi)
  • guselkumab (Tremfya)
  • infliximab (Remicade)
  • ixekizumab (Taltz)
  • risankizumab (Skyrizi)
  • secukinumab (Cosentyx)
  • tildrakizumab (Illumya)
  • ustekinumab (Stelara)

How long do psoriasis injections last?

The amount of time the medications will last varies. The type of medication being used will determine how long it remains effective and how often a person will need additional doses.

Injections for psoriasis can take between 3 and 6 months to begin working. During that time, a person’s doctor may suggest other treatments to manage psoriasis symptoms.

A person can continue taking injections for psoriasis as long as the medications are deemed effective.

How often does someone get injections for psoriasis?

The time between injections will depend on the type of medication a person is prescribed.

For example, etanercept injections are given twice weekly for 3 months and then once a week thereafter. And after an initial injection of ustekinumab, the follow-up injections will occur at 4 weeks and then every 12 weeks.

Some of these medications are administered in the doctor’s office each time. Other types will require a visit for the first injection that includes instructions on how a person can administer the following doses at home.

Which is the best medication for psoriasis?

The best medication for psoriasis can differ from person to person and will depend on many factors, including whether the person has:

  • mild, moderate, or severe psoriasis
  • other conditions, such as psoriatic arthritis
  • other health concerns, such as a pregnancy or liver damage
  • insurance coverage for specific medications
  • had a response to other treatments in the past

A person’s doctor will work with them to consider the various factors and determine the best options for treatment.

Biologics and other injectable drugs can be effective in treating severe to moderate psoriasis, although sometimes there may be side effects.

A person should discuss their medication with their doctor and inform them of any changes or concerns.