What are the key clinical features to differentiate between inflammatory and non-inflammatory joint pain in adults?

To differentiate between inflammatory and non-inflammatory joint pain in adults, key clinical features include the pattern of pain, presence of specific signs, and associated systemic symptoms ¹,²,⁴,⁵.

• Inflammatory Joint Pain: Inflammatory joint pain often presents with prolonged morning stiffness ⁴, and the pain may improve with movement ². Symptoms can wake a person during the second half of the night ². Clinical signs include synovitis, which manifests as joint swelling, tenderness, or loss of joint function ¹. The affected joint may also be hot and red ⁴,⁵. Inflammatory conditions can affect small joints of the hands or feet, or involve more than one joint ¹,³. There may be general fatigue ¹ and increased inflammatory markers, such as C-reactive protein ¹. Specific features like dactylitis (swelling of a whole digit) or enthesitis (inflammation where tendons or ligaments attach to bone) are strong indicators of inflammatory arthritis, particularly spondyloarthritis ². Other associated features can include current or past psoriasis, uveitis, inflammatory bowel disease, or a family history of spondyloarthritis or psoriasis ². Gout, a type of inflammatory arthritis, typically presents with a rapid onset (often overnight) of severe pain, redness, and swelling, commonly in the first metatarsophalangeal (MTP) joint, and may involve tophi ⁵. Pain from inflammatory conditions may improve within 48 hours of taking a nonsteroidal anti-inflammatory drug (NSAID), and non-NSAID analgesics will not control the inflammation ².
• Non-Inflammatory Joint Pain (e.g., Osteoarthritis): In contrast, non-inflammatory joint pain, such as that seen in typical osteoarthritis, generally does not involve prolonged morning joint-related stiffness ⁴. The affected joint is typically not hot or swollen ⁴. Rapid worsening of symptoms or deformity, or a history of recent trauma, are considered atypical features for osteoarthritis, suggesting other potential causes ⁴.