The exact cause is unknown, but it thought to be due to the immune system attacking healthy cells and triggering an excess growth of skin cells.
Psoriasis is a chronic condition that cannot be cured, only controlled. If over-the-counter treatments, lifestyle changes, and prescription drugs don't work, injections may help.
These are not usually a first-line treatment for psoriasis, but they are effective at reducing plaques.
As with all medications, there are side effects that a person must consider before starting to have the injections.
There are a number of injection options available to help manage psoriasis that use special types of proteins that target the immune system.
The injection medications used to treat psoriasis are known as biologic drugs, or simply "biologics."
These medications are made from living cells grown in a laboratory. Special types of proteins are harvested from these cells. They can then be used to target specific immune system proteins that can cause cells to grow too fast.
The United States Food and Drug Administration (FDA) have approved several medications to treat psoriasis.
These medicines will target special T cells in the immune system. They also stop proteins in the immune system from growing.
Examples of these proteins include tumor necrosis factor-alpha (TNF-alpha), interleukin-17A, or interleukins-12 and -23.
Doctors only usually prescribe these medicines when a person's psoriasis is moderate to severe.
Interleukin-12 and -23
The proteins interleukin-12 (IL-12) and interleukin-23 (IL-23) are linked to psoriasis symptoms.
By blocking the actions of these proteins, a person may have less psoriasis inflammation. The medication ustekinumab (Stelara) is FDA-approved to treat psoriasis.
Similarly to interleukin-23, interleukin-17A is associated with causing an immune system reaction that can lead to psoriasis.
Examples of FDA-approved psoriasis injections that block interleukin-17A include secukinumab (Cosentyx) and ixekizumab (Taltz).
Tumor necrosis factor-alpha blockers
Tumor necrosis factor-alpha blockers (TNF-alpha blockers) are those that stop a protein known as a cytokine from causing inflammation in the body.
When a person has a condition such as rheumatoid arthritis or psoriasis, the body produces too much TNF-alpha. By blocking production, a person should not have psoriasis skin symptoms.
The FDA have approved the following TNF-alpha blockers to treat psoriasis:
- adalimumab (Humira)
- certolizumab pegol (Cimzia)
- etanercept (Enbrel)
- golimumab (Simponi)
- infliximab (Remicade)
The medication Remicade is delivered via intravenous (IV) infusion instead of a standard injection.
In addition to the earlier-mentioned biologics, the medication methotrexate (Trexall, Rheumatrex) is also used to treat psoriasis. It is available as either an oral medicine in pill form or as an injection.
Methotrexate is not a biologic. Instead it is a disease-modifying anti-rheumatic drug, or DMARD. The medication works by suppressing the immune system.
Sometimes a person will take both methotrexate and psoriasis injection medication.
The FDA have approved the injections Cimzia, Enbrel, Humira, and Remicade for treatment with methotrexate.
Originally, doctors prescribed methotrexate in larger dosages as a chemotherapy agent to treat cancer. Now, it is prescribed to treat a number of health conditions, including psoriasis and rheumatoid arthritis.
However, not everyone can take methotrexate and it is associated with quite a few side effects.
Injections for psoriasis can be very effectively and don't require a person to take a pill, or pills, daily. Instead, a person gets their regular injection and can go about their daily life. Some people may use psoriasis injections along with topical preparations or light therapy.
Also, injectable medications may be the only treatment those with moderate to severe psoriasis have found effective. Sometimes a person may have been using a psoriasis treatment for a while and it has become less effective. Biologics can be a new treatment option to help them.
Injections of TNF-alpha blockers have the added benefit they may help to reduce long-term joint damage in patients with psoriatic arthritis.
Injections may cause a higher risk of flu-like symptoms and respiratory infections.
Psoriasis injections may impact the immune system. As such, there are a number of health considerations a person and their doctor must make before using the medication.
First, the medicines may make a person more at risk of contracting infections, such as tuberculosis. Individuals must be screened for tuberculosis before and during treatment with psoriasis injections.
The effects of biologics on pregnant women aren't known. As a result, they are rarely prescribed to women who are pregnant or nursing.
Side effects related to psoriasis injections can range from mild to severe. Examples of the more common side effects include:
- higher risk for respiratory infections
- greater chances for flu-like symptoms, like low energy and body aches
- reactions at the injection site, such as redness, swelling, or discomfort
Rarer side effects associated with taking psoriasis injections include:
- blood disorders
- increased risk for certain cancer types
- increased risk for serious nervous system disorders, including multiple sclerosis, nervous system inflammation, and seizures
Methotrexate can cause a separate set of side effects. The most common side effects are nausea, appetite loss, and being tired.
However, long-term methotrexate treatments can lead to liver damage and affected red and white blood cell production.
A doctor should instruct a person receiving psoriasis injections as to the symptoms that could indicate an infection. Psoriasis sufferers should call their doctor if they experience those symptoms.
Other treatment options
Several different psoriasis types exist. When prescribing a treatment a doctor will consider:
- the psoriasis type
- where a person's symptoms are
- how severe their symptoms are
Topical treatments are often the first line of care for those with psoriasis.
Examples include topical corticosteroids, which are responsible for reducing rates of inflammation in the skin. They are used to treat mild to moderate psoriasis.
Before considering injections, people with psoriasis will usually try topical treatments.
Other treatments include:
- vitamin D analogues
- anthralin (Dritho-Scalp)
- calcineurin inhibitors, such as tacrolimus (Prograf)
- salicylic acid
- coal tar
- topical retinoids, such as tazarotene (Tazorac, Avage)
Additional medication options
Other treatments exist in addition to methotrexate that can be taken orally to treat psoriasis. Examples include oral retinoids and cyclosporine. A new treatment for psoriasis is the pill, apremilast (Otezla).
This medication is known as a phosphodiesterase 4 (PDE4) inhibitor. As PDE4 is associated with causing inflammation that can lead to psoriasis, taking Otezla may help to reduce the incidence of psoriasis plaques.
Light therapies are a treatment option that involve exposing the skin to a certain amount of ultraviolet light.
However, excess ultraviolet light is associated with an increased risk for skin cancer. As such, a person with psoriasis must strike a careful balance of sun exposure and beneficial light exposure.
If a person lives in an area where there is not a lot of sun exposure, they can expose their skin to an artificial light source. An example of this is a light box.
Psoriasis is an inflammatory skin condition. As such, lifestyle triggers associated with inflammation can sometimes worsen a person's symptoms. Examples include:
- intense or prolonged sun exposure
While these factors don't trigger every person's psoriasis symptoms, they have been known to trigger symptoms in some cases.
Avoiding these factors or triggers could help to lessen symptoms. Similarly, avoiding alcohol can help reduce psoriasis symptoms as alcohol could affect how well psoriasis medicines work.
Another home treatment is taking daily soothing baths with lukewarm water. Adding substance such as bath oil, colloidal oatmeal, Dead Sea salts, or Epsom salts may help. Applying moisturizers to the skin after taking a bath may also be beneficial.
When to see a doctor
If a person is receiving psoriasis injections, they should contact their doctor if they experience signs of an infection.
As psoriasis injections affect the immune system, these infections may be more difficult to treat.
Examples of symptoms a person may need to call their doctor about include:
- flu-like symptoms
- sores that do not heal
While flu-like symptoms can be a side effect of the injections, it's important that a person check in with their doctor regarding symptoms.