According to HCP Live, University of Lübeck researchers recently connected rheumatoid arthritis (RA) and pemphigus, an autoimmune disorder characterized by blisters on the skin and mucous membranes. In fact, researchers now believe that patients with pemphigus are twice as likely to develop RA than others. They launched this line of inquiry based on “‘autoimmune diathesis,” or the idea that patients with autoimmune disorders run a higher risk of developing other autoimmune disorders. Read the full research findings published in Immunologic Research.

The Research

Altogether, the study analyzed data sourced from 1,985 patients with pemphigus over a 10-year period. This data was compared with that of a healthy control group of 9,875 people. Overall, researchers determined that patients with pemphigus had slightly higher rates of RA. For example, 1.8% of the control group had RA, compared to 2.3% of the patient group. However, researchers note that this is not necessarily statistically significant.

Later, during the follow-up, 40 additional patients developed RA (15 patients and 25 controls). After performing calculations, researchers determined that patients with pemphigus were still much more likely to develop RA than other groups. Researchers believe this may have to do with T-cells and pro-inflammatory cytokines like interleukin 17, which play a role in the immune response.

Despite their findings, researchers advocate for additional research and investigation on this link in the future.

Rheumatoid Arthritis (RA)

Rheumatoid arthritis (RA) is a chronic inflammatory disorder. Because it is an autoimmune condition, it occurs when the immune system mistakenly attacks tissues and joints, including those in the hands and feet. While RA typically progresses slowly, it may also progress rapidly or simply plateau. RA may occur in periods of symptoms and remission. This condition is more common in females than in males. Symptoms include:

• “Pins and needles” sensations
• Fatigue
• Anemia (low red blood cell count)
• Joint pain, weakness, stiffness, swelling, and tenderness
• Muscle, back, and joint pain
• Restricted movement
• Redness or lumps under the skin

Pemphigus

Pemphigus is a chronic autoimmune disorder affecting the skin and mucus membranes. In short, the immune system mistakenly identifies these as invaders and attacks them, causing pain and lasting damage. Pemphigus can be triggered by drugs, though many times the trigger is unknown. Risk factors include being of Middle Eastern or Jewish descent, or being middle-aged. There are two forms of pemphigus: vulgaris and foliaceus.

Typically, pemphigus foliaceus is characterized by sores and blisters on the chest, back, and shoulders. While these sores itch, they are often not painful. In this form, no blisters are present in or around the mouth.

Alternately, pemphigus vulgaris is characterized by painful blisters in the mouth. Additionally, this form may spread to the genital mucous membranes.

Additional complications of pemphigus include difficulty eating and swallowing, infections, malnutrition, and death. Learn more about pemphigus.