Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis, with a prevalence estimated between 0.3% and 1% of the population. It typically starts as oligoarticular and mild, but can progress to polyarticular and severe in 20% of patients. PsA is distinct from rheumatoid arthritis (RA) and is associated with specific clinical features such as distal joint involvement, enthesitis, and spinal involvement. It is also linked to HLA class 1 alleles, unlike RA which is associated with HLA class 2 alleles. PsA is more common in patients with psoriasis, with estimates suggesting 30% of psoriasis patients have PsA. The disease can lead to significant joint damage, reduced quality of life, and increased mortality, especially in severe cases. PsA is classified with spondyloarthropathies due to features like spondylitis and HLA-B27. Clinical features include dactylitis, which is inflammation of an entire digit. PsA is often diagnosed in patients with psoriasis, and nail changes are a distinguishing feature. The disease can progress over time, with some patients achieving remission but often experiencing flares. PsA patients have a higher risk of mortality, related to disease severity and other factors. The Health Assessment Questionnaire (HAQ) and the Medical Outcome Survey Short Form 36 (SF-36) are used to assess quality of life and functional status in PsA patients. A specific quality of life instrument for PsA is also being developed. Overall, PsA is a complex and severe condition with significant impact on patients' health and quality of life.Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis, with a prevalence estimated between 0.3% and 1% of the population. It typically starts as oligoarticular and mild, but can progress to polyarticular and severe in 20% of patients. PsA is distinct from rheumatoid arthritis (RA) and is associated with specific clinical features such as distal joint involvement, enthesitis, and spinal involvement. It is also linked to HLA class 1 alleles, unlike RA which is associated with HLA class 2 alleles. PsA is more common in patients with psoriasis, with estimates suggesting 30% of psoriasis patients have PsA. The disease can lead to significant joint damage, reduced quality of life, and increased mortality, especially in severe cases. PsA is classified with spondyloarthropathies due to features like spondylitis and HLA-B27. Clinical features include dactylitis, which is inflammation of an entire digit. PsA is often diagnosed in patients with psoriasis, and nail changes are a distinguishing feature. The disease can progress over time, with some patients achieving remission but often experiencing flares. PsA patients have a higher risk of mortality, related to disease severity and other factors. The Health Assessment Questionnaire (HAQ) and the Medical Outcome Survey Short Form 36 (SF-36) are used to assess quality of life and functional status in PsA patients. A specific quality of life instrument for PsA is also being developed. Overall, PsA is a complex and severe condition with significant impact on patients' health and quality of life.