Reactive Arthritis vs Psoriatic Arthritis: What Are the Differences?

Reactive arthritis is the term used when arthritis (joint inflammation) results from a reaction to an infection in another body area. It is also sometimes called Fiessinger-Leroy disease or Reiter's syndrome. Psoriatic arthritis is a chronic and autoimmune arthritis type defined by joint inflammation occurring with the skin condition psoriasis. The Arthritis Foundation says a third of people living with psoriasis develop psoriatic arthritis.

Symptoms

In reactive arthritis, your large joints in your lower limbs, pelvis, and lower spine are most commonly targeted by your immune system. Characteristic symptoms may occur separately, all at once, or not at all. Onset is usually rapid with two to four joints becoming inflamed within a few days. Symptoms usually last anywhere from 3 to 12 months and may come and go over the course of years. These symptoms can vary greatly from one person to the next.

When you have psoriatic arthritis, you can experience joint inflammation and characteristic psoriasis plaques or red patches with silvery scales. Psoriatic arthritis can affect your large or small joints, and much less commonly, the spine. It can also affect your organs.

Causes

While there are some undeniable overlaps in symptoms experienced, and there is a shared genetic association between these two disorders (specific genetic marker called HLA-B27.), the underlying causes of each are ultimately different.

Reactive arthritis

Reactive arthritis is said to usually develop in reaction to an infection and commonly follows bouts of bacterial infections including:

• Chlamydia (sexually transmitted infection)
• Bacterial intestinal infections caused by salmonella
• Shigella
• Yersinia
• Campylobacter.

Not everyone who experiences these infections will experience reactive arthritis.

Psoriatic arthritis

The cause of psoriatic arthritis is not clear ,but researchers think it’s a combination of genetic variations, vulnerability (psoriasis runs in families), and being triggered by environmental factors or external causes like:

• Infection
• Stress
• Physical trauma
• Mechanical stress on joints (i.e. wear-and-tear)

Gene variations in the HLA family (human leukocyte antigen (HLA) complex) appear to affect one’s risk of developing psoriatic arthritis, disease severity, and disease progression. However, it’s not quite clear exactly how this works.

Diagnosis

There is no clear diagnostic criteria that the medical community agrees upon for reactive arthritis. Similarly, there is no definitive blood test or single exam that can confirm psoriatic arthritis.

For both conditions, the diagnostic process will look like this: Your healthcare provider will take a full medical history, conduct a physical examination, and make the final diagnosis based on your results including those from any X-rays (for later stage psoriatic arthritis).

Common lab tests for diagnosis of arthritis types include:

• Rheumatoid factor and anti-CCP are types of blood tests to help diagnose rheumatoid arthritis.
• HLA-B27 are blood test to help diagnose, may also be indicated with a family history of psoriasis or psoriatic arthritis.
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) may show presence of inflammation.

Depending on your specific symptoms, you will be referred to a specialist for official diagnosis and to develop a treatment plan.

If you are diagnosed with reactive arthritis, you will likely be referred to an arthritis specialist known as a rheumatologist. People with psoriatic arthritis can also see rheumatologists and may see dermatologists for their skin-based symptoms.

Treatment

There are different methods of treating these two arthritis types. This is why getting an accurate diagnosis (as early on as possible) is important. Here are the common treatments for each type.

Reactive arthritis

You may need to see more than one specialist for your treatment, depending on your symptoms. These experts can target your treatment to your specific needs. 

Treatment options include: 

• Antibiotics: Antibiotics can treat the bacterial infection that triggered the reaction. Your medical professional will choose which antibiotic will be most effective in this case and the duration you need to take it for. 
• Non-steroidal anti-inflammatory drugs (NSAIDs): NSAIDs can help with inflammation and associated pain. Examples include ibuprofen and naproxen.
• Corticosteroids: For cases not helped by over-the-counter NSAIDs, you can talk to your doctor about corticosteroid injections directly into the affected joint to reduce symptoms. Corticosteroids also come in topicals or creams available OTC and by prescription for relieving joint inflammation and pain.
• Physical therapy: Working with a physiotherapist can help you increase your range of motion and strengthen the affected area. It’s important to seek professional advice to prevent injury or further trauma to the joint.

Psoriatic arthritis

When it comes to psoriatic arthritis, treatment focuses on slowing or stopping disease progression, reducing inflammation and pain, treating the psoriasis skin symptoms, and keeping your joints as mobile as possible.

Treatment options include:

• Non-steroidal anti-inflammatory drugs (NSAIDs): NSAIDs can be helpful in cases of joint inflammation and reducing swelling or pain from skin plaques.
• Corticosteroids: You can take them orally or by injection at a doctor’s office. The Arthritis Foundation says doctors try to use this option at the lowest dose for the shortest time to reduce risk of side effects like facial swelling or bone loss.
• Disease-modifying antirheumatic drugs (DMARDs): DMARDs like methotrexate are used for their general immune-suppressing effects (telling your body to stop attacking itself). 
• Hot/cold therapy: Therapies include heat that can help improve circulation to reduce joint stiffness and cold therapies to help reduce swelling by constricting blood vessels.
• Working with a certified physiotherapist: This can help you learn and stick with safe strengthening and flexibility exercises that can help increase your range of motion. Physiotherapists can also suggest assistive or mobility devices if necessary.

Prevention

Doing your best to prevent these two illnesses requires different strategies because of their different causes. However, if you do these prevention strategies and still end up with an infection or psoriatic arthritis, it’s not your fault and it doesn’t mean you failed. Some contributing factors may be outside your control. 

Reactive arthritis

The best you can do to prevent reactive arthritis is try to prevent the infection that triggers it. For example, practicing safe sex—including safe oral sex—can help reduce your risk of a chlamydia infection, which occurs most often in men 20 to 40 years old. The other common triggers are typically bacteria that get into your digestive tract from contaminated food sources, so be sure to practice safe food practices.

Psoriatic arthritis

Preventing psoriatic arthritis isn’t exactly possible due to the autoimmune nature of the illness. However, preventing symptom flare-ups can help you to reduce their frequency and severity and getting the right treatment can help slow disease progression. 

The first step to preventing flare-ups is understanding your personal triggers and how to avoid or limit them. For example, if you smoke, it's helpful knowing smoking is a trigger or risk factor for psoriasis (ie., it can make you more likely to experience symptoms).

Your medical care team can support you through your personal trigger discovery process and help you make realistic changes, which is another reason why getting the right diagnosis and working with healthcare professionals is so important.

A Word From Verywell

Knowing which type of arthritis you have is important because not all joint inflammation is from the same source. Now that you’ve read how truly different reactive arthritis and psoriatic arthritis are, it may be clearer which relates to your symptoms or not.

The important takeaway is that only a medical professional can get the diagnosis process started and only you can make that happen. While it may seem daunting, it’s necessary for getting the right treatment so you can have a higher quality of life.