People with ankylosing spondylitis (AS) often share a few common characteristics, and more than 90% of those diagnosed have the HLA-B27 gene. Typical symptoms of ankylosing spondylitis include sacroiliitis, gradual onset low back and hip pain, and early morning stiffness.
However, the condition can also cause symptoms in the upper spine, eyes, lungs, and heart. Though these symptoms are relatively rare, they do occur and often appear unrelated—sometimes making it difficult to accurately diagnose. The following is a list of several uncommon symptoms of ankylosing spondylitis:
Over time, the joints where the ribs and spine meet and where the ribs and sternum (breastbone) meet can no longer expand as they once did. This pathology is due to the long-term inflammation and scar tissue buildup associated with ankylosing spondylitis—in this case, around the lungs and between the ribs. As a result, people with AS can experience severe chest pain that can be mistaken for a more serious cardiac condition.
Rarely, ankylosing spondylitis can affect the heart. Because of this, and to rule out other serious conditions, people with ankylosing spondylitis who experience chest pain should consult their doctor for evaluation of serious cardiac diagnoses.1
- Iritis (or inflammation of the iris)
Iritis is an inflammatory condition that affects the eye’s iris. The iris is part of the eye’s middle layer, called the uvea, and doctors sometimes refer to iritis as uveitis. It often occurs in one eye at a time and may have a quick onset (acute iritis) or develop gradually (chronic iritis). Acute iritis will improve quickly if treated immediately at onset; chronic iritis can last for months or years.
People with ankylosing spondylitis experiencing the following symptoms should have their eyes checked by a professional:
- Eye pain, pain around the eye, and headache
- Sensitivity to light
- Physical symptoms such as redness or changes to pupil shape
- Blurred vision, cloudy vision, or floating specks
Approximately 30 to 40% of people with ankylosing spondylitis will experience iritis at least once.
Cauda equina syndrome
Ankylosing spondylitis patients experiencing bowel or bladder incontinence or other neurological deficits (such as numbness of the extremities, trouble speaking, loss of balance) may have developed cauda equina syndrome. This syndrome can result from the extensive compression of the nerve bundle at the bottom of the spine or the widening of the dural sac around the spinal cord (dural ectasia) caused by the condition.
Cauda equina syndrome is a medical emergency. Anyone experiencing its symptoms should seek medical treatment immediately. Ongoing treatment for cauda equina syndrome with ankylosing spondylitis (sometimes referred to as CES-AS syndrome) may include steroids and surgery.
Formerly referred to as secondary amyloidosis, AA amyloidosis is the buildup of the protein amyloid in the organs. Amyloid is produced in bone marrow, but the cause of amyloid production, or its link to inflammatory disorders such as ankylosing spondylitis, is unknown. Like ankylosing spondylitis, it is also difficult to diagnose. It primarily affects the kidneys, but may also negatively impact the heart, liver, or digestive system.
Amyloidosis has its own collection of symptoms, including numbness in the hands and feet, feeling full quickly, weight loss, and swelling in the legs and ankles. By the time the condition has progressed far enough for symptoms to be present, organs are typically affected and a doctor should be consulted.
- Cardiac lesions
Some people with ankylosing spondylitis may experience chronic inflammation at the base of the heart, around the aortic valve and aorta. This sustained inflammation can result in lesions.
Fewer than 2% of people with ankylosing spondylitis will experience cardiac lesions.
People living with ankylosing spondylitis who begin to experience new or worsening symptoms should consult their rheumatologist early to minimize complications and review their current treatment plans for effectiveness.