Ankylosing spondylitis (AS) is a form of arthritis. AS is a chronic inflammatory disease that affects your spine, causing pain and limiting range of motion. It can involve disease flare-ups that cause acute symptoms, followed by remissions in which symptoms ease up.
AS varies a lot from person to person. Symptoms can be severe, but not everyone with AS develops spinal fusion or has serious complications. Neither age nor gender affects the severity of the disease.
While it was once thought to be more prevalent in men, that may be due to underdiagnosis in women. Also, women may have a more advanced disease at the start of treatment due to delayed diagnosis.
Some research does suggest differences in women versus men, but findings have been inconsistent.
Part of the problem is that research has focused heavily on men, but that’s starting to change. Some recent studies have included more women, but there’s not enough data yet to reach firm conclusions about sex differences in AS.
Continue reading as we explore the role of gender in AS.
The exact cause of AS is not clear, but genetics play a role. One risk factor for AS is having a family history of the disease.
AS occurs when the spinal vertebral bodies, and the ligaments and tendons that attach to these bones of the spine, become inflamed. Over time, this swelling causes severe problems within your back.
At first, you may experience frequent back pain or overall stiffness, which may be worse in the morning. You might notice that it improves a bit after a warm shower or a little exercise.
As AS progresses, the pain can become debilitating and cause a reduced range of motion. You might also experience pain in other areas of the body, including the neck, shoulders, elbows, knees, or ankles.
Some people experience only intermittent back pain and discomfort, while others have severe pain and stiffness over multiple areas of the body for long periods of time. AS can be debilitating and, in some cases, lead to disability.
Early symptoms can also include mild fever and loss of appetite. Other symptoms may include fatigue, anemia, and inflammation of the eyes (iritis or uveitis) or bowels.
People with AS may be at higher risk for depression. A 2014 study found that when compared with the general population, there’s an 80 percent increased rate of depression in women, and 50 percent in men with AS.
Many people with AS have a gene called HLA-B27. However, having this gene doesn’t mean you’ll develop AS.
The link between HLA-B27 and AS varies by race and ethnicity. For example, among Caucasians, about 95 percent of those who have AS test positive for the gene. About 80 percent of people from Mediterranean countries do, while only about half of African-Americans with AS test positive for this gene.
Genetic risk factors appear to be the same for men and women.
Arthritis is often considered a disease that comes about with age. But AS commonly occurs in people between the ages of 17 and 45. Some people are diagnosed as early as adolescence.
The age of onset is about the same in men and women.
It was previously thought that men with AS are more prone to pain in the spine and back than women. Later research indicates that back pain is the main symptom for both men and women seeking diagnosis.
In addition, women may have more neck, hip, and knee pain, while men have more foot pain.
AS affects men and women during their peak reproductive years, but does not appear to affect fertility. But for men, certain medications used to treat AS can decrease sperm count. If you’re trying to conceive, review your medications with your doctor.
Women with AS who are pregnant or trying to conceive should work with their doctors to find the right medications and to keep inflammation under control.
Symptoms such as stiff spine and back pain can continue throughout pregnancy. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil) often help relieve pain from AS, but can cause harm to your unborn child. Other medications can pass through breast milk to your baby.
The diagnosis of AS is usually made by a rheumatologist. There’s no single test for AS, so reaching that diagnosis in both men and women may include:
- individual and family medical history
- evaluation of symptoms
- physical examination
- imaging tests
- blood work
Blood tests can’t definitively diagnose AS, but they may be of use. They can rule out other diseases and test for the HLA-B27 gene.
Certain markers, such as elevated erythrocyte sedimentation rate (ESR or SED) and C-reactive protein (CRP) are inflammation indicators. But not all people with AS have them. They can also be due to such conditions as anemia, infection, or cancer.
Recent research found that men with AS have elevations of IL-17A and Th17 cells, but this wasn’t true of women.
The assumption that AS is a predominantly male condition may delay diagnosis in females. In addition, studies have generally included many more men than women. Newer studies are addressing this. But much more research is needed to broaden understanding of any gender differences.
If you have symptoms of AS, such as back or neck pain, see your primary care doctor as soon as possible. If it appears to be an inflammatory condition, you’ll likely be referred to a rheumatologist for evaluation.
After diagnosis, it’s important to see your rheumatologist at least once a year, even if your symptoms are currently mild.
There’s no cure for AS. But early detection and treatment can help alleviate pain and may prevent disease progression in both men and women.