What duration of morning stiffness might indicate ankylosing spondylitis?

• A. Less than 15 minutes
• B. More than 30 minutes
• C. Variable length
• D. Only with activity

Answer: (B)

The indication of more than 30 minutes of morning stiffness is significant in diagnosing ankylosing spondylitis. This condition is a type of inflammatory arthritis primarily affecting the spine and can lead to a reduced range of motion and chronic pain. Patients with ankylosing spondylitis often experience prolonged morning stiffness due to the inflammatory nature of the disease, which leads to stiffness and discomfort, especially after periods of inactivity or immobility during the night.

In contrast, morning stiffness lasting less than 15 minutes typically suggests a more mechanical or non-inflammatory condition, which is not characteristic of ankylosing spondylitis. Variable length stiffness may be seen in other conditions but doesn't specifically point to this diagnosis. Lastly, stiffness that only occurs with activity may also indicate different types of musculoskeletal issues rather than the sustained morning stiffness associated with ankylosing spondylitis. Therefore, recognizing the duration of morning stiffness as a critical factor aids healthcare professionals in differentiating ankylosing spondylitis from other rheumatologic or mechanical disorders.