Pyoderma gangrenosum (also called ulcerative dermatitis) is an often very painful inflammatory disease of the skin. It often occurs in connection with autoimmune diseases. The front edges of the tibia are a typical place where the skin is affected.
It usually begins with skin changes that can be raised (papules) and also with blisters, which can also be filled with pus and are then referred to as pustules. As the disease progresses, skin ulcers (also called ulcers) develop.
If the tissue in the center of the ulcer dies, it is called central necrosis. The transition to normal (unaffected) skin is usually very red, swollen and looks as raised as a wall.
Causes of pyoderma gangrenosum
The development of a pyoderma gangrenosum is not fully understood. It is clear, however, that this is not an infection by microorganisms. The skin change is often associated with autoimmune diseases.
People who already have ulcerative colitis are particularly prone to developing these ulcers. In fact, about five percent of patients with ulcerative colitis will develop gangrenous pyoderma. In Crohn's disease, however, only one percent developed such a skin disease. Pyoderma gangrenosum can also occur in connection with rheumatoid arthritis or chronic bronchitis. It can also be observed that the skin changes can occur after injuries, such as an operation.
Find out more about: Ulcerative colitis and Chron disease
Diagnosis of pyoderma gangrenosum
The diagnosis of pyoderma gangrenosum is usually made clinically. That means based on the changes that can be seen in the skin. The extent to which these phenomena change over time is also always taken into account. With this clinical picture it is also important to rule out an infection of the skin by microorganisms such as bacteria. For this purpose, a swab can be made from the wound or colonization of the blood by blood cultures can be excluded. In rare cases, a microscopic examination of a tissue sample can be carried out, but this is only useful in the early stages of pyoderma gangrenosum.
What stages are there?
At the beginning the pyoderma gangrenosum shows up as one or more protrusions of the skin. In the course of the process, bubbles appear that keep getting bigger. These blisters can also be filled with purulent fluid and are then called pustules.
Eventually the bubbles break down and ulcers remain. Often larger areas of skin are affected. As part of the healing process, extensive scars develop. The skin now often has a pigmentation disorder in this area. So it may be that the pitted skin is darker or lighter than the original skin color.
Accompanying symptoms of pyoderma gangrenosum
Unfortunately, pyoderma gangrenosum has been described as a very painful condition. Besides the pain and the appearance of the skin, there are no other symptoms. It should only be ensured that the open skin is protected as well as possible from germ colonization in order to avoid additional infection. If there are other physical symptoms, it is advisable to consult a doctor who is familiar with autoimmune diseases, as pyoderma gangrenosum often occurs as part of these diseases. In this case, the accompanying symptoms could indicate the presence of an autoimmune disease such as ulcerative colitis or Crohn's disease
This article might also interest you: What is an autoimmune disease?
Therapy of pyoderma gangrenosum
For the therapy of pyoderma gangrenosum drugs from the group of immunosuppressants are used. These are drugs that weaken the body's immune system. They are useful here because the body keeps this disease going through its excessive inflammatory reaction. Cyclosporin A is the first choice, but other glucocorticoids can also be used.
For local treatment, the open skin wound should first be protected from the ingress of germs with non-adhesive bandages. There are special wound dressings that promote granulation, which means that they aid wound healing. These dressings are also recommended for pyoderma gangrenosum. It can also be helpful to freshen the wound edges again and again (that means making targeted skin incisions on the wound edges again), which rekindles the healing process.
Also read the article on the topic: Immunosuppressants
The application of a compression bandage is recommended for other diseases such as chronic venous insufficiency, which are also associated with leg ulcers. The aim here is to promote the venous drainage, which is ultimately responsible for the formation of the ulcers. But this is not the case with pyoderma gangrenosum. The causes here lie in a dysregulation of the immune system and the disease affects the arteries rather than the veins. A compression bandage would probably worsen the wound healing and is therefore not recommended.
What are the chances of recovery?
The disease pyoderma gangrenosum usually heals, but with scarring. If the disease is related to an autoimmune disease, the skin can repeatedly become infected. In this case, it is very important to treat the underlying disease, such as ulcerative colitis, as well as possible.
Also read the article on the topic: Therapy of ulcerative colitis
What is the connection with Chron disease?
Crohn's disease is an autoimmune disease that primarily affects the intestines. Since the entire immune system is affected in this form of the disease, symptoms can also occur outside the gastrointestinal tract. Pyoderma gangrenosum as a skin phenomenon is one of the typical symptoms outside of the gastrointestinal tract. About one percent of Crohn's disease patients have pyoderma gangrenosum.
Find out more about the topic: Diagnosis of Chron disease