Occurrence of joint pains with swelling in patient with psoriasis is called Psoriatic arthritis.It usually develops in setting of established diagnosis of psoriasis but some are unaware that they have psoriasis. It should be suspected in a patient who have asymmetrical arthritis with negative rheumatoid factor. 10% - 40% of psoriasis patients develop arthritis. In 10% - 15% of patients suffering with psoriasis arthritis develops earlier than skin and nail lesions. Other musculo skeletal in these patients are enthesitis, dactylitis(sausage shaped digits), digital interphalangeal with or without terminal digital absorption, sacroilitis, in distractive arthritis called as arthritis mutilens. Extraarticular features in these patients can be in the form of like conjunctivitis, iritis, ulcers in the mouth and involvement of heart. No laboratory test is the diagnostic. Radiographs, ultrasound, MRI, HLA B 27 aid in diagnosis.
Due to diversity in clinical symptoms, available treatments are not effective for all features further complicating therapeutic decisions. Apart from traditional approach to use pain killers, methotrexate and biologics had changed the outcome of these patients by decreasing the suffering and deformities.
In early stages the diagnosis depends mainly on presenting features, clinical examination by rheumatologist and a positive family history. In 70%, ESR/CRP is elevated. A definitive diagnosis can be made by imaging. HLA B27 is usually positive in these patients.
Early diagnosis, supervised treatment and physical therapy are essential for good outcome. NSAIDs are the main stay of treatment but are associated with potential adverse effects when used for prolonged period. Role of systemic steroids in this disease lacks scientific evidence. Recently newer drugs like biologics are available for treatment to improve functional outcome in those with severe disease.