Ankylosing Spondylitis in Women

Medically Reviewed by Melinda Ratini, MS, DO on July 27, 2022
4 min read

In the past, experts believed ankylosing spondylitis (AS) affected men more than women. But now, they know it happens to them at the same rate.

This type of arthritis usually affects men and women in young adulthood. But its symptoms, diagnosis process, and treatment aren’t the same.

To understand how to treat separate people with this type of arthritis, experts have done lots of studies looking at the differences in men and women who have it. While it can act similarly in all people at times, there are some key differences:

The time it takes to get a diagnosis. AS is a variant of spondyloarthritis, a disease that causes inflammation in your spine and joints. One study found that it takes about 6½ years for men to get a spondyloarthritis diagnosis after their condition begins. For women, it takes almost 9 years.

Other data showed that men were diagnosed with spondyloarthritis 7 months before women.

But researchers found that these delays don't have to do with differences in symptoms. Age is also not a reason, since men and women typically develop AS at the same time of life.

Instead, experts believe the delay in diagnosis for females is linked to bias.

Some doctors may give medical care to women differently. This can affect how well they’re able to discover their correct condition. For example, your doctor might downplay your symptoms or tell you your side effects are from another disease.

The risk of a misdiagnosis. Axial spondyloarthritis (axSpA) refers to a category of spondyloarthritis. AS is in this category. One study found that nearly 25% of females with axSpA were misdiagnosed at first.

A misdiagnosis means your doctor diagnosed you with a condition that isn’t the disease you have. The condition you’re wrongly diagnosed with may have had similar symptoms to axSpa. But your doctor may have missed key differences.

The same study found that females with axSpA had widespread pain as a symptom. It also found that, in this group of people, doctors often misdiagnosed them with fibromyalgia. This condition has some similar symptoms to axSpA, such as widespread pain in your bones and other areas.

The level of radiographic damage. Your doctor can measure your radiographic damage through scans like X-rays. This type of damage refers to your joint erosion from AS.

Most studies showed that men had more progression on these scans than women. Because of this, males appear to have faster progression of their AS than do women.

But this doesn’t mean spondyloarthritis is worse overall for men. Men just show more obvious signs of its progression. But disease activity, impairment, and pain are about the same for men and women.

Symptoms. Some studies have found that women are more likely than men to have axSpA symptoms that affect more than just their joints. But others didn’t find any difference between these symptoms in males and females.

Acute anterior uveitis is a condition that causes severely painful red eyes that can lead to vision loss. This is the most common nonjoint related symptom of spondyloarthritis. One study found it’s more common in females than males. But different studies disagree on this. Some found it affects men more.

Enthesitis is the inflammation of your entheses, which are areas where your tendons or ligaments insert into your bone. Doctors see this symptom more often in females with spondyloarthritis than in males with the condition. Enthesitis is more severe for women.

Different and often more intense symptoms may explain why the severity of AS is often worse in females than males.

Other conditions. Women with AS might be more likely to have certain comorbidities. A comorbidity is a condition you have along with your AS.

Studies suggest that females with spondyloarthritis have higher rates of inflammatory bowel disease (IBD) than males with the same condition.

Some researchers also found that women with axSpA tend to have psoriasis more often than men with axSpA.

Your disease activity and pain scores. Multiple studies suggest that women have more pain and a harder time overall with axSpA.

The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) measures your disease activity for AS. Studies using this index found females had more fatigue, back pain, and longer periods of morning stiffness.

How your body responds to treatment. Experts have found that overall, treatment is much less effective in women than in men with axSpA.

There weren’t many women in past studies that looked at treatment for this condition. But as experts begin to pay more attention to gender differences within AS, they see the large gap in treatment success for males and females.

Women with AS are twice as likely as men to not stick with their treatment routine.

This may have to do with the fact that treatment may not be as effective for them. Treatment is often more successful in people with less enthesitis and shorter length of disease. Both of these aren’t common in women.

Experts need more research to understand why some AS therapies don’t work as well for women.

Your overall quality of life. Most studies found that women with AS had a lower quality of life than men.

But there were some quality of life questionnaires that found no big differences between men and women. They also found that even when doctors control AS inflammation the same in men and women, women still tend to report a worse quality of life than men do.