Psoriatic arthritis is an inflammatory form of arthritis that is characterized by swelling, stiffness, and pain and is often accompanied by skin and nail psoriasis; it can affect any joint, including fingers and toes. Psoriatic arthritis affects an estimated 0.3% to 1% of the US population (>3 million people). Furthermore, as many as 30% of individuals with psoriasis will have psoriatic arthritis.

An estimated 7.5 million people in the United States have psoriasis, a chronic, inflammatory, autoimmune disease. Psoriasis is characterized by thick patches of inflamed, scaly skin resulting from excessive proliferation of skin cells. The disease typically affects the scalp, knees, elbows, hands, feet, lower back, and joints; it can also affect nails, the soft tissues of the genitals, and the inside of the mouth. In some cases, psoriasis can lead to disfigurement and disability.

Inflammatory autoimmune conditions can affect different body systems, resulting in a variety of diseases involving the joints, skin, brain, and other organs.

Psoriatic arthritis, a progressive, potentially debilitating type of arthritic inflammation, affects approximately 7 million people in the United States.

By Lisa A. Raedler, PhD, RPh, Medical Writer Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that affects at least 1.3 million adults in the United States.1 Symptoms include pain, stiffness, swelling, and limited motion and function of many joints, particularly the small joints in the hands and feet.1 A diagnosis of RA is made on the basis of symptoms, physical examination results, and blood tests that are positive for anemia, rheumatoid factor, antibodies, and elevated erythrocyte sedimentation rate.1 Continued inflammation of the synovium can lead to cartilage and bone damage.1,2

By Loretta Fala, Medical Writer Psoriatic arthritis (PsA), a chronic, inflammatory disease that causes pain, stiffness, and swelling in and around the joints, generally develops between the ages of 30 and 50 years, but it can affect people of all ages, including children.¹ In the United States, the overall prevalence of PsA is estimated to range from 101 to 250 cases per 100,000 people; however, the prevalence of PsA has historically been challenging to determine, because of its misdiagnosis and the lack of widely accepted diagnostic criteria.² PsA is sometimes misdiagnosed as rheumatoid arthritis, gout, or osteoarthritis.³

By Lisa A. Raedler, PhD, RPh Systemic juvenile idiopathic arthritis (SJIA) is a rare inflammatory disease, affecting approximately 10% of children diagnosed with juvenile idiopathic arthritis in the United States.1,2 The classic symptoms of SJIA include pain in the small joints of the hands, wrists, knees, and ankles; rash; and a high, spiking fever of ≥103°F that can last for weeks to months.3 By definition, SJIA can pre­sent at any point until the age of 16 years. However, a long-term outcomes study found that the median age at diagnosis of SJIA was 4 years.4 The distribution of the disease by sex is roughly equal.