How to deal with it in an examination
Psoriatic arthritis occurs in up to 10% of people with skin psoriasis and can precede or follow the skin disease by months or years. In addition to inflammation of the joints, psoriatic arthritis has other, extra-articular features including nail changes, enthesitis (inflammation at the site in which a tendon inserts into bone, commonly the plantar fascia and Achilles tendon insertions), and ocular inflammation, such as conjunctivitis or, less often, iritis or uveitis.
Psoriatic arthritis can resemble rheumatoid arthritis. Distinguishing the two is largely a matter of clinical judgment, looking at the pattern of joints affected, although a negative rheumatoid factor blood test can be useful to rule out rheumatoid arthritis. Box 1 summarises the different treatments for psoriatic arthritis (box 1).
Psoriatic arthritis is classified into five types. In clinical practice, a high degree of overlap exists between categories, but this system helps to explain the disease.
Ask the patient