If you have unexplained blisters appearing on your body, pemphigus and pemphigoid could be to blame. These are autoimmune blistering disorders that are not contagious. 

“These conditions are caused by an immune system gone awry and manifest as blisters in the skin or membranes such as the mouth, nose and eyes,” says Yale Medicine dermatologist Mary M. Tomayko, MD, PhD. “These are extraordinarily rare diseases,” she says.

The immune system normally fights off infections. In people who have pemphigus and pemphigoid, the immune system malfunctions and creates antibodies that begin to attack normal body structures, causing blisters.

Symptoms of these diseases can include pain in the mouth, bleeding when brushing teeth, recurrent bloody noses, red eyes, pain while urinating or with bowel movements, or tenderness during intercourse, depending on where the blisters develop. Bullous pemphigoid is often very itchy. “Some people will have visible sores on their skin—either fluid-filled blisters or open sores,” says Dr. Tomayko. Some people have blisters only in their mouths or in another mucous membrane, like the eyes. Others have them only on their skin, and some have a combination of these.

• Pemphigus is characterized by shallow ulcers or fragile blisters that break open quickly.
• Pemphigoid presents with stronger or “tense” blisters that don’t open easily. Those with pemphigoid are also more likely to have hot, red and itchy hive spots.

“Because the blisters are tense, those resulting from pemphigoid are more likely to leave permanent marks on the skin,” Dr. Tomayko says. “When the eyes are affected, scarring and vision loss can result. It is important to seek care.”

While pemphigoid is much more common than pemphigus, chances of getting either are very low. Only about 12 American adults in 100,000 have pemphigoid.

“People who get these diseases are genetically predisposed,” says Dr. Tomayko. “They could have a difference in their immune responses that make them a little more prone to getting these diseases. Exposures throughout their lives and age-related changes in the immune system could also put them at a higher risk, though we don’t know the triggers. In short, it’s a combination of genes and environment that we’re still getting a handle on.”

These disorders can affect anyone, at any age, from any part of the world, though pemphigoid sufferers tend to be over 60 years old.

Bullous pemphigoid is more common in people with pre-existing neurological diseases such as Parkinson’s disease or dementia. “The link between these two kinds of disorders is an active area of research here at Yale Medicine,” Dr. Tomayko says. “Our working hypothesis is that because people who have Parkinson’s and dementia have elevated levels of antibodies against collagen proteins, their immune systems are primed to attack the skin.”

A physical exam is a very important component in diagnosing these diseases, so your doctor can determine the location and distribution of the blisters and their type. A clinician will also do a skin biopsy—analyzing a skin sample under the microscope—to look for specific antibodies.

The standard initial treatment is corticosteroids, which are administered topically and orally.

“You don’t want to be on high doses of corticosteroids in the pill form for a long time because of the side effects,” says Dr. Tomayko. “So we also use other medications, injections and infusions that suppress the body’s immune response and deplete the antibodies. Mycophenolate mofetil and rituximab are two common ones.”

The majority of patients with these disorders will see very significant improvement after three months of treatment. Some patients go into a long-term remission after that, while others will need a second treatment a year later. Most will require ongoing treatment.

Even without any treatment, these disorders tend to “burn out” after five to 10 years in some people.

“We are very comfortable and familiar with these disorders,” says Dr. Tomayko. “We have a team of medical dermatologists who use cutting-edge diagnostic tools.”

Dr. Tomayko also regularly interacts with a global network of experts in these disorders. “They are particularly helpful in situations where a patient is resistant to treatment,” she says. “We rely on one another to develop treatment plans when they can’t be algorithmic.”

Because Tomayko and her colleagues are studying pemphigus and pemphigoid in the lab, patients come to see Yale Medicine doctors have access to more treatment options. They might also have the opportunity to take part in research studies.

“When a patient is badly flaring or has new onset disease, our hospital is a good place to be, not just in terms of a diagnosis, but for treatment,” Dr. Tomayko says. “Wound care is highly specialized when it comes to these disorders. Our nurses and attending physicians are familiar with the most comfortable and effective dressings and procedures.”

Patients we see understandably wonder if they can be cured. “These are conditions that we can manage very well,” says Dr. Tomayko. “Patients are not ‘cured,’ per se, but the symptoms can be controlled, skin will heal if cared for properly, and, over the long term, there is a good likelihood that the disorders will go away.”