Psoriatic Arthritis vs. Multiple Sclerosis: Symptoms, Causes, Treatment

Psoriatic arthritis (PsA) refers to a type of arthritis that affects your joints and skin. PsA develops in about a third of people with the skin condition known as psoriasis. Psoriasis is characterized by dry, thick, and raised red patches on the skin.

Multiple sclerosis is when your body attacks and destroys the protective covering of nerve cells (myelin sheath or fatty coating) of the brain, spinal cord, and/or eyes.

Both are progressive diseases, so it’s crucial to get the right diagnosis to help reduce damage to affected areas and make symptoms more manageable. 

Symptoms 

PsA and MS have some overlapping symptoms due to their autoimmune nature. There are some significant differences, though, and what’s more, in both cases no two people will have the same symptom experiences. With MS in particular, there are so many different possible symptoms and symptom combinations that it’s fair to say it’s rare for two people with MS to have the same symptoms.

Symptoms in both conditions may also fluctuate or come and go.

Causes

While there are some clear similarities in these autoimmune diseases, their underlying causes and contributing factors do differ.

Psoriatic Arthritis

There’s no single cause of PsA, although researchers have associated the condition with certain types of genes known as human leukocyte antigens (HLAs). These antigens have some connection to your risk of developing PsA, but what the risks are and the extent to which they have an effect are currently unclear.

Other factors like getting an infection, having a family member with psoriasis or PsA, and stress can also contribute to the underlying risk factors of developing PsA.

Multiple Sclerosis

The cause of MS isn’t clear yet, either, but researchers are working to learn more. What they know so far is that exposure to bacterial infections can trigger MS years later; natural sunlight and vitamin D, gene variations or mutations, and immune system dysfunction are all associated factors.

For example, the Cleveland Clinic explains that cases of MS are more concentrated in areas farther from the equator. These areas get less sunlight, which results in less exposure to natural vitamin D. That vitamin D deficiency is a risk factor for developing MS.

Diagnosis

The diagnostic process is similar in both cases because there is no definitive blood test for either disease.

In both cases, you will be asked for a full medical history, and there will be lab tests required to test for signs of inflammation in your blood.

Some form of medical imaging, like an X-ray or magnetic resonance imaging (MRI), will be conducted to see if there are internal markers of inflammation or if there are lesions more characteristic of multiple sclerosis. This step is crucial to differentiate between arthritis, which causes joint damage in specific locations over time, and MS, which causes pain because of central nervous system damage (i.e., the myelin sheath breakdown).

Diagnostic Differences

With PsA, you’ll need to see a skin specialist called a dermatologist to confirm psoriasis. However, not everyone with PsA has or develops psoriasis.

If your medical care provider suspects MS, you will also be given a neurological examination to test your overall brain functioning (i.e., coordination, memory, response times). Brain and spinal cord fluid analysis (also known as a spinal tap or lumbar puncture) are also necessary for a diagnosis of MS and other neurodegenerative diseases but not for psoriatic arthritis.

Treatment 

In both diseases, treatment doesn’t mean “cure.” Treatment options also vary quite considerably, which is another sign of the importance of getting an accurate diagnosis by a medical professional or team of professionals.

Psoriatic Arthritis 

Treatment for PsA looks like managing your symptoms of psoriasis (if present) and managing your symptoms of joint pain and inflammation.

A board-certified dermatologist can help you develop the right treatment plan for your psoriasis symptoms, which can depend on their location. For example, you can use medicated ointments, creams, gels, and foams on elbow psoriasis, but this can be more challenging in hair-covered areas like the scalp. Seeing a rheumatologist will help you develop a care plan for those symptoms related to joint inflammation. 

Medications (Topical, Oral, or Injectable)

Your specialist will suggest an over-the-counter (OTC) option or prescription medication to ease symptoms caused by your inflammatory responses. 

Medication options for PsA include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Corticosteroids (intermittent use)
• Disease-modifying anti-rheumatic drugs (DMARDs), which are broad-based immunosuppressants
• Biologic agents (also known as biologics) that can be useful if other treatments fail to reduce inflammation

Treatments also include:

• Exercise to maintain or increase range of motion
• Heat and cold therapy
• Joint protection and energy conservation
• Splinting
• Surgery (rare for this type of arthritis)

Multiple Sclerosis

Treatment for MS is also about managing symptoms and slowing the disease course. Since MS pain is neurological (i.e., nerve pain rather than joint pain as in the case of arthritis), NSAIDs may not provide much relief but can still be used for other types of musculoskeletal pain.  

Treatment options include:

• Topical medications such as lidocaine gel or Zostrix (capsaicin topical analgesic) for reducing tingling and burning
• Steroids for eye nerve inflammation
• Anti-seizure drugs including (first-line, newer drugs) Neurontin (gabapentin) and Lyrica (pregabalin); (second-line) Tegretol (carbamazepam) and Dilantin (phenytoin)
• Anti-anxiety agents, including Cymbalta (duloxetine hydrochloride) and Klonopin (clonazepam)
• Tricyclic antidepressants, including Elavil (amitriptyline), Pamelor (nortriptyline), and Norpramin (desipramine)
• Surgery to reduce pressure on certain areas 
• Botox (botulinum toxin) can be effective in treating migraine headaches (common in MS). Botox also helps with other pain, including pain from muscle spasms in MS.

Coping 

While you can’t exactly prevent PsA or MS, you can take steps to reduce their negative impact on your life, including the frequency and duration of symptoms. In both cases, making healthy choices is a way of coping with chronic illness.

The American Psychological Association offers some healthy coping strategies for when you are first diagnosed with any chronic illness:

• Confront your diagnosis by bringing all questions to your medical provider.
• Ask about all options for disease management to get the full picture and make an empowered choice.
• Try practicing control in other areas, including choosing healthy meals, avoiding unnecessary stress, and taking all medications as prescribed.
• Reduce the amount of time spent with people who are not supportive (this can just add more stress and feed into feelings of denial or self-shame).

You may also want to consider:

• Working with a physiotherapist to maintain or improve mobility
• Working with a registered dietitian to create a simplified menu that provides nutrients but doesn’t exhaust energy
• Joining an online or in-person support group for people living with PsA or MS to connect with people who have a better chance of understanding what you’re experiencing and need

A Word From Verywell

If you notice any of the symptoms of PsA or MS, contact your medical care provider. In both cases, these disorders can become disabling and require proper treatment plans to manage.

The good news is that when you have a diagnosis, you have a reason for why you’ve been feeling unwell. Many options for treatment also become available. You can find what works and what you need to be the healthiest version of you that is possible. Great improvements in everyday living can be achieved with the support of trained professionals.