Rheumatoid arthritis (RA) is a chronic inflammatory disease that causes pain, weakness and malformation of the joints. It is a systemic disease that affects the entire body, including vital organs, the eyes and the skin. Long-term inflammation can cause general changes to the skin’s texture, color and durability, and acute skin lesions and infections may also arise.
Rheumatoid arthritis can cause a variety of changes to the skin. Commonly, the skin becomes thin, wrinkled and fragile which can lead to easy bruising. The palms may become reddish in color (called palmar erythema), while the skin on the back of the hands can turn pale in color and even appear translucent.
Rheumatoid arthritis can cause lumps to form beneath the surface of the skin, particularly in the area of affected joints. These are called subcutaneous or rheumatoid nodules. Subcutaneous nodules occur in approximately 25 percent of rheumatoid arthritis patients and are more common among men than women. They are firm to the touch and are usually benign and painless, although they may cause pain if they occur in an area prone to repetitive irritation such as the fingers, soles of the feet, heel, back or forearms. Complications like infection or ulceration can occur if the skin covering the nodules breaks down.
Vasculitis is a potentially serious complication of rheumatoid arthritis. When blood vessels that have been damaged by rheumatoid arthritis start to bleed, they can cause sores on the surface of the skin. The sores–commonly found on the legs–can become ulcerated and painful. They are typically dark purple in color and are called purpura or petechiae. Vasculitis can also cause symptoms in other areas of the body, including loss of sensation, an enlarged liver or spleen, blood in the urine and bowel ulcers. Vasculitis can lead to gangrene, or death of the skin tissue in the affected limb.
Pyoderma gangrenosum may occur in as many as 37 percent of rheumatoid arthritis patients. It causes ulcerated lesions, commonly on the lower limbs but feasibly anywhere on the body. The ulcers grow very quickly and may be exacerbated by injury or trauma. As they grow, layers of skin tissue begin to die (called necrosis). Prompt treatment—often with corticosteroids—is necessary to prevent serious complications from necrotic skin tissue and infection.
Other Rare Skin Conditions
Rheumatoid arthritis is associated with some rare inflammatory skin conditions, including neutrophilic disorders. Neutrophils are a type of white blood cell that increases in number in response to a bacterial infection. Patients with rheumatoid arthritis may develop inflammatory neutrophilic dermatoses, skin conditions characterized by raised papules on the skin’s surface. Under the microscope, an infiltration of neutrophils can be seen as evidence of the infection.
Interstitial granulomatous dermatitis is another rare skin condition whose symptoms include redness and irritation and red papules on the surface of the skin.
Urticaria, commonly known as hives, may also occur in those with rheumatoid arthritis. It is characterized by an eruption of itchy papules on the skin’s surface.