Final answer:
Psoriatic Arthritis is an autoimmune condition characterized by swelling of entire digits, joint pain, and stiffness. X-ray evidence can support the diagnosis with unique signs like the 'pencil-in-cup' deformity. Blood tests are used primarily to rule out other conditions like rheumatoid arthritis.
Step-by-step explanation:
Psoriatic Arthritis Overview
Psoriatic Arthritis (PsA) is a type of inflammatory arthritis associated with the skin condition psoriasis. One clear distinction is that it affects the entire digit (a phenomenon called 'dactylitis'), making fingers or toes swell up to look like sausages. Unlike osteoarthritis (OA), which is primarily a degenerative joint disease, PsA is also an autoimmune condition.
Demo
PsA typically appears in individuals between the ages of 30 and 50 but can occur at any age. Both men and women are equally likely to be affected.
Signs
Common signs include joint pain, stiffness, and swelling, with the distinctive characteristic of dactylitis. It may also involve the spine, leading to a painful condition known as spondylitis.
X-ray Signs
X-rays may show joint damage and bone proliferation unique to PsA, known as 'pencil-in-cup' deformity, among other signs.
Lab
Laboratory tests for PsA are used to rule out other conditions such as rheumatoid arthritis (RA). Blood tests might be done looking for rheumatoid factor or anti-cyclic citrullinated peptide (anti-CCP) antibodies, which are typically negative in PsA.