How does rheumatoid arthritis affect the skin?
Often associated with deformities in the hands and other extremities, rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder that can affect other parts of the body, too, including the skin, lungs, digestive system, and possibly the brain. It requires medical interventions to help alleviate symptoms and prevent joint damage.
Around 1 in 100 people has RA, but only some will develop a rash as a part of the disorder. These rashes can form on various parts of the body and may cause pain. Fortunately, treatments are available to help alleviate the discomfort, redness, and swelling.
What is a RA rash?
Most people with RA do not develop a rash.
Advanced cases of RA can cause several skin conditions, including a rash. Rashes only affect a small percentage of people with RA, however.
RA rashes can appear on the skin as red, painful, and itchy patches. They may also be seen as deep red pinpricks. The most common site for a rash associated with RA is on the fingertips.
In some advanced cases, a rash may form painful ulcers. The ulcers can become infected and cause further complications.
RA rashes are caused by inflammation of the arteries that the body uses to bring blood to the various organs, including the skin and nerves.
The inflamed arteries are known as rheumatoid vasculitis and can cause spots or patches of an RA rash on the surface of someone's skin.
Inflamed arteries on or around the fingertips may cause painful spots to form. Inflamed arteries in the legs are more likely to cause a larger area to develop a rash.
People with an RA rash are likely to experience the following in the affected areas:
- small to large red patches
- pain sensation
- swelling of the skin
Advanced cases of RA rash may form ulcers or lesions.
Some of the following images may be considered graphic:
Neutrophilic dermatosis associated with rheumatoid arthritis
Ulcer on the skin
Interstitial granulomatous dermatitis
Image credit: Nantsupawat T et al, Journal of investigative medicine high impact case reports, 2013
Other skin conditions related to RA
RA is associated with several different skin conditions. A person may experience none, one, or multiple skin conditions due to their RA. These include the following:
Nodules are hard lumps that form directly under the skin. They range from about the size of a pea to that of a golf ball. They may develop over bony or fleshy areas of a person's body.
Nodules are not usually painful but may be treated directly to reduce their size. In rare cases, surgery may be required to remove the nodule, especially if the nodule is infected.
RA medications may be the cause of rashes on a person's skin. These rashes are believed to be allergic reactions to the medications.
Medications that may cause a rash include:
If a person experiences a rash as a side effect of medication they are taking, they should tell their doctor. Depending on the severity of the reaction, the doctor may change the dose or the medication itself to a different one.
It is important not to suddenly discontinue or reduce a medication without speaking to a doctor.
A doctor may also prescribe an antihistamine to combat or reduce the reaction, or even steroids for severe reactions.
Medications that are used for the treatment of RA can also make a person more susceptible to other skin problems. For example, some of the drugs cause a person to bruise more easily or be more sensitive to sunlight.
Some people with RA experience chronic or recurring hives that develop on the skin. Hives are similar to a medication rash, but they may form independently of a medication. Allergists now recognize chronic, unexplained hives as a symptom of RA.
Livedo reticularis is a skin condition that is only occasionally associated with RA. However, some research suggests that serious underlying conditions can cause livedo reticularis.
Livedo reticularis is often considered a benign rash that occurs or becomes more evident during colder weather. The condition is caused by spasms in blood vessels that produce a net-like pattern of purplish lines.
Livedo reticularis can cause other complications, including:
- painful nodules
The condition can also indicate the presence of a peripheral vascular disease or a clot in the blood vessels.
In most cases, treatment for rashes caused from RA focuses on dealing the underlying condition. Reducing the severity of RA symptoms will usually help clear up the rash.
In more severe cases of RA rash, a doctor may treat the rash directly. In these instances, a doctor may prescribe topical antibiotics or steroids to help treat or prevent any secondary infections.
A person may consider skin creams and ointments to treat an RA rash. These can be used to help reduce the pain or itchiness. Topical steroids may also be considered to reduce the swelling.
In cases where the skin rash is directly caused by a reaction to RA medication, a doctor can advise a person on how to reduce or replace their current medication.