lOMoAR cPSD| 67928686
Rheumatology Study Guide: Psoriatic Arthritis Focus |
Comprehensive Revision Notes, Key Concepts & Quiz Practice
2026
Rheumatology Quiz 4 Study Guide
Psoriatic Arthritis
• The exact cause of psoriatic arthritis is unknown – it is considered autoimmune.
• Inflammatory asymmetric joint distribution.
• May or may not be associated with psoriasis.
• May have additional features such as dactylitis, enthesitis, or inflammatory back
pain.
• Markers for RA are (usually) negative.
• Lab findings are NOT specific for PsA.
• GI dysbiosis plays a large role in disease progression.
[Dactylitis: “any inflammatory process involving the fingers or toes” can be
considered dactylitis. Depending on the type of condition you have, different tissues
may be involved in different types of swelling.
In PsA, “sausage-like” digits are common. In addition to PSA, these diseases include
ankylosing spondylitis, enteropathic arthritis, reactive arthritis, juvenile PsA, and
undifferentiated PsA. RA may sometimes have this sign as well. However, RA is a
disease that is indicated primarily by swollen joints.)
When it comes to sausage-like digits, some distinct differences between RA and PsA
can help you tell the conditions apart. According to ASSH, RA often occurs in both
hands, while PSA frequently affects just one hand.
The swelling patterns can also be different. RA usually involves swelling of the large
finger joint, called the MCP joint, or wrist swelling. Psa patients more often have to swell
at a joint called the DIP, which is at the end of their fingers. Middle finger joints (PIP)
can also be affected in PsA.] Clinical Features:
• Pain and stiffness, which is alleviated with physical activity.
pg. 1
, lOMoAR cPSD| 67928686
• Usually asymmetric, distal arthritis (DIP joints).
• Can be symmetric and indistinguishable from RA.
• Inflammation is deforming and destructive.
• History of psoriasis is present in 70% of patients.
• There is a weak correlation between skin flares and joint flares.
• Additional features: Dactylitis, enthesitis, tenosynovitis, nail lesions, pitting edema,
uveitis, conjunctivitis.
Diagnostic testing:
• Lab testing is NOT specific and will not distinguish it from other forms of
inflammatory arthritis.
Diagnosis:
(2006 CASPAR Criteria: a total of at least 3 points from the following list)
• Skin psoriasis
• Nail lesions
• Dactylitis
• Negative RF
• Juxtaarticular bone formation on X-ray (not osteophytes) Poor Prognosis:
• Increased number of actively inflamed joints
• Elevated ESR
• Previous medication failure
• Presence of joint damage
• Loss of joint function
• Diminished quality of life Conventional Treatment:
• NSAIDs
• Initial treatment – effective in bringing inflammation down
• DMARDs
• Used when arthritis does not respond to NSAIDs
• (Do NOT slow or prevent joint damage)
• TNF-Inhibitors
pg. 2
Rheumatology Study Guide: Psoriatic Arthritis Focus |
Comprehensive Revision Notes, Key Concepts & Quiz Practice
2026
Rheumatology Quiz 4 Study Guide
Psoriatic Arthritis
• The exact cause of psoriatic arthritis is unknown – it is considered autoimmune.
• Inflammatory asymmetric joint distribution.
• May or may not be associated with psoriasis.
• May have additional features such as dactylitis, enthesitis, or inflammatory back
pain.
• Markers for RA are (usually) negative.
• Lab findings are NOT specific for PsA.
• GI dysbiosis plays a large role in disease progression.
[Dactylitis: “any inflammatory process involving the fingers or toes” can be
considered dactylitis. Depending on the type of condition you have, different tissues
may be involved in different types of swelling.
In PsA, “sausage-like” digits are common. In addition to PSA, these diseases include
ankylosing spondylitis, enteropathic arthritis, reactive arthritis, juvenile PsA, and
undifferentiated PsA. RA may sometimes have this sign as well. However, RA is a
disease that is indicated primarily by swollen joints.)
When it comes to sausage-like digits, some distinct differences between RA and PsA
can help you tell the conditions apart. According to ASSH, RA often occurs in both
hands, while PSA frequently affects just one hand.
The swelling patterns can also be different. RA usually involves swelling of the large
finger joint, called the MCP joint, or wrist swelling. Psa patients more often have to swell
at a joint called the DIP, which is at the end of their fingers. Middle finger joints (PIP)
can also be affected in PsA.] Clinical Features:
• Pain and stiffness, which is alleviated with physical activity.
pg. 1
, lOMoAR cPSD| 67928686
• Usually asymmetric, distal arthritis (DIP joints).
• Can be symmetric and indistinguishable from RA.
• Inflammation is deforming and destructive.
• History of psoriasis is present in 70% of patients.
• There is a weak correlation between skin flares and joint flares.
• Additional features: Dactylitis, enthesitis, tenosynovitis, nail lesions, pitting edema,
uveitis, conjunctivitis.
Diagnostic testing:
• Lab testing is NOT specific and will not distinguish it from other forms of
inflammatory arthritis.
Diagnosis:
(2006 CASPAR Criteria: a total of at least 3 points from the following list)
• Skin psoriasis
• Nail lesions
• Dactylitis
• Negative RF
• Juxtaarticular bone formation on X-ray (not osteophytes) Poor Prognosis:
• Increased number of actively inflamed joints
• Elevated ESR
• Previous medication failure
• Presence of joint damage
• Loss of joint function
• Diminished quality of life Conventional Treatment:
• NSAIDs
• Initial treatment – effective in bringing inflammation down
• DMARDs
• Used when arthritis does not respond to NSAIDs
• (Do NOT slow or prevent joint damage)
• TNF-Inhibitors
pg. 2
