By Afsaneh Khetrapal, BSc (Hons)
Rheumatoid arthritis (RA) is a systemic autoimmune illness. It is the result of the body’s immune system producing antibodies against its own antigens, causing damage to the target organs. Like most other autoimmune diseases, RA occurs three times more often in women as compared to men.
Symptoms of RA include chronic progressive joint pain, severe joint inflammation and in many cases, total loss of joint function.
Most cases of RA show symmetrical joint involvement. The pain of RA is typically worse on waking. RA, in contrast to osteoarthritis, which also causes joint inflammation and pain, causes symptoms in a host of organs than just the joints.
RA is thus associated with a number of skin conditions highlighted below. In general, the severity of skin involvement indicates to which form the RA belongs:
Rheumatoid Nodules (Subcutaneous Nodules)
These are the most common dermatological manifestation of RA, affecting up to one-fifth of patients with RA. These firm subcutaneous nodules of tissue arise most frequently over joints affected by RA. Therefore, they are most commonly found over the elbow, finger, or behind the heel. More rarely, nodules may develop on the vocal cords and in the lungs. These nodules are generally non-tender and painless. It is uncommon that the patient experiences pain related to the nodules, and in the rarest of situations does the skin over the nodule show signs of infection or ulceration.
Small nodules are usually not treated. Larger ones may be treated with corticosteroid injections into the lesions, or with anti-rheumatic drugs. If a nodule is painful or infected, as may occur when it is subjected to friction or repeated trauma, it may require surgical excision.
Approximately 1 in 100 people with RA show signs of rheumatoid vasculitis (RV). It is an uncommon complication of RA, therefore. Yet, in a few patients, the presence of subcutaneous nodules indicates RV.
This is a complication seen most typically in severe and long-standing RA. It refers to the inflammation of blood vessels in the skin along with joint inflammation. The vessels most commonly affected in this manner are those that supply blood to the nerves and to numerous organs, in addition to the skin. RV can thus impact the peripheral nervous system, the blood vessels that supply the extremities (fingers and toes), causing a pitted appearance, redness, or sores that form on the fingertips and around the nails. In more serious cases it may even cause digital ischemia. In some patients with RA, it may affect larger vessels. In these individuals, sensitive rashes may form on areas such as the legs. More alarming manifestations include the formation of ulcers which have the potential to become infected, or the appearance of scleritis, namely, inflammation of the white part of the eye.
Pharmaceutical Side Effects
Many of the skin conditions that are seen in RA sufferers are caused by the prescription medications that they take to ease symptoms or control the disease.
Skin rashes are a common manifestation of RA. They may be a sign of an allergic reaction to a drug. Following the assessment of the type of rash and its severity, it may be necessary to lower the dosage of a prescribed medication, or even to stop it entirely. In some cases, the administration of anti-histamines or corticosteroids may be required to arrest the cutaneous drug reaction.
Some drugs which may be responsible for such skin rashes include:
Reviewed by Dr Liji Thomas, MD.
Last Updated: Aug 21, 2016