No, Ankylosing Spondylitis Is Not Rheumatoid Arthritis

"I have ankylosing spondylitis or AS," I tell the busy-body woman who I know through friends and family. She's asking me how I'm doing — "and what is it you suffer with again, darling?" — because she's seen me post about AS on social media and she thinks she's an expert at everything anyone says. You know the type.

But because she's showing genuine care, I indulge her line of questioning. I repeat it again: "Ankylosing Spondylitis. You can just say AS."

"Ah, ALS. That's a motor thing, right? Neurodegenerative," she responds confidently.

"No, no," I correct her. "Not ALS. I have AS, no L in the middle. It's ankylosing spondylitis. It's inflammatory. Musculoskeletal, arthritis. A disease that affects my spine," I rattle off.

She looks at me in a flash of what I thought might be recognition. Acknowledgment?

"Oh, like RA?"

Ah, there it was. 

If I didn't have to be polite to her because of family, I probably would have snapped just a bit

There's this cozy idea that to be a patient advocate or a patient leader you have to be nice and sweet all the time in some effort to educate and advocate.

But why? I'm capable of supporting the chronically ill, but that doesn't mean I get to have my disease flippantly spoken about or confused with other diseases. If you don't know, just ask. 

"Rheumatoid arthritis (RA) doesn't fuse the spine together," I answer, not bothering to go into specifics on either disease.

"Oh dear," she retorts. "I've got a bit of arthritis in my knee."

Reader, if you could have seen my face. Is this not the most common response we get? Somehow, inflammatory arthritis—with a hundred other symptoms—is inevitably likened to mechanical, age-related wear and tear. I wonder how these people with wobbly knees manage to pay for their immunotherapy, I wonder.

Oh, right. They don't have to. 

For a long time, people have been wondering if AS is part of RA

I blame a clear lack of initial clinical understanding, a lack of general public awareness around AS, and the fact that people don't take the time to Google things.

Although this lack of research and awareness is changing these days (hello! I'm here writing this!), I still see things like this on Google:

"Is ankylosing spondylitis part of rheumatoid arthritis?" or "Is ankylosing spondylitis rheumatoid or osteoarthritis?"


The research

Even the experts only just published this 2022 piece in StatPearls, titled, "Rheumatoid Arthritis And Ankylosing Spondylitis," explaining the difference:

"Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are among the most common rheumatic diseases. These chronic progressive inflammatory diseases lead to a reduction in physical fitness and increase in joint degeneration. Although very closely related, their symptomatology and etiology are different. In the past, AS was often diagnosed inaccurately as RA, but the two have recently been recognized as separate, distinct clinical entities.  The latter has been attributed to advancing diagnostic and laboratory techniques able to differentiate the two conditions. That being said, the diagnostic differentiation still remains a challenging task for clinicians."1

If you're interested in the differences, read up. I'm still not sure how they're determining that AS is more common in men (since we know this isn't true),2 but it's a good entry point.

Don't be like my family friend here. Ask questions. Do research. Your words and assumptions matter.

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