A Guide to Crohn’s Disease and Skin Issues

While Crohn’s disease is a type of inflammatory bowel disease (IBD), it can also be a cause or factor in different types of skin rashes or lesions in your mouth, on your anus, or other areas of the body.

When you live with Crohn’s disease, inflammation causes damage to your intestines, resulting in symptoms such as diarrhea and abdominal pain.

For some, Crohn’s disease can also lead to issues outside of the digestive tract and abdomen. This can be the result of Crohn’s itself, related conditions, or treatments. If you live with the condition, you may notice rashes and lesions develop in different areas of your body.

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What types of skin symptoms are related to Crohn’s disease?

An estimated 6–40% of people living with Crohn’s disease experience symptoms outside of their digestive tract. These may be referred to as extraintestinal manifestation. One of the most common symptoms is the development of skin rashes or lesions.

Crohn’s can affect your body’s ability to absorb necessary vitamins, like zinc, iron, or vitamin C. This can cause skin rashes or changes.

In addition to skin issues that develop due to Crohn’s, you may experience skin issues as a result of a reaction to a medication you use as a treatment. It’s also possible to develop other conditions, like psoriasis or vitiligo, which affect the skin.

The following sections describe some of the most common skin issues associated with Crohn’s disease that may develop.

Erythema nodosum

About 6–15% of people living with Crohn’s disease will experience erythema nodosum.

With erythema nodosum you may notice the development of painful or tender nodules or red bumps under the skin. They often appear on the front of the shins.

Though they can appear with Crohn’s disease, several other conditions can cause erythema nodosum’s development, including:

• use of hormonal birth control
• pregnancy
• certain cancers
• certain infections, such as strep throat or tuberculosis
• autoimmune diseases

Pyoderma gangrenosum

About 1–2% of people living with Crohn’s disease will develop pyoderma gangrenosum.

This condition causes the development of pus filled lesions that may expand in size or appear in groups. The lesions can range in size from a few centimeters to affecting an entire area of skin.

The lesions often appear on the legs, but they can appear on any part of your body.

Though they can heal, you have a risk of developing them again, particularly during a flare up of Crohn’s disease. They can also lead to severe scarring.

Perianal lesions

Perianal lesions are fissures (cracks or breaks in the skin), ulcers, or fistulas (holes connecting two areas of tissue) that occur around your anus. They may be:

• painful
• swollen
• red

These can affect about 33% of people living with Crohn’s disease.

Oral lesions

Oral lesions occur in the mouth, often on the inside of your cheeks.

Some experts don’t classify oral lesions, such as fissures, abscesses, ulcers, and others as an extra-intestinal manifestation. Instead, they think that since Crohn’s disease can affect any part of the digestive tract from the mouth to the anus, lesions in the mouth shouldn’t be considered odd or out of the ordinary.

Symptoms of oral lesions can include:

• swelling
• painful ulcers
• cracked lips
• cracked patches at the corners of the mouth

About 10% of people living with Crohn’s disease will experience oral lesions.

Metastatic Crohn’s disease

A rare type of skin condition, metastatic Crohn’s disease occurs when skin lesions appear on areas not directly associated with the digestive or intestinal tract. The lesions typically:

• appear as nodules or plaques
• are red to purple
• appear on the face, genitals, extremities, or areas where skin rubs against itself

Sweet’s syndrome

A relatively uncommon type of skin rash associated with Crohn’s disease, Sweet’s syndrome or acute febrile neutrophilic dermatosis often affects those assigned female at birth.

When it occurs, it can cause tender papules and plaques often on the neck, head, and upper extremities. About 28% of cases are diagnosed at the same time as the initial diagnosis of Crohn’s disease.

Why does Crohn’s cause skin rashes or lesions?

Experts still do not fully understand why Crohn’s disease affects the skin. This is a topic of continuing study for scientists.

What they do know is:

• some lesions and rashes are caused by Crohn’s itself, while others are caused by related or similar conditions
• some skin issues may be due to reactions to medications and other treatments
• certain autoimmune disorders, such as psoriasis, may occur alongside Crohn’s disease

More research is still needed to fully understand how Crohn’s disease causes or relates to issues with the skin.

Treatments

Treatments for skin lesions due to Crohn’s or associated with the condition will vary. You should discuss any skin issues you have with a doctor who can help identify and provide specific treatment to meet your needs.

Treatment may include systemic medications. These medications help to control the immune system and reduce inflammation. Examples include corticosteroids and immunosuppressive drugs.

Other treatments may involve taking steps such as:

• managing Crohn’s disease and preventing flares
• using supplements
• undergoing procedures to heal fistulas
• discontinuing medications if they caused the issue

When to see a doctor

You should see a doctor if you notice new or worsening symptoms related to Crohn’s disease or skin rashes. They can help make adjustments to treatment as needed.

It’s important to consult with your doctor before making changes. They can help determine the cause of the skin changes and the best treatment options to fit your needs.

They can also make changes to your medications as needed.

The bottom line

Skin rashes often occur alongside Crohn’s disease. You should consider speaking with a doctor if new skin lesions develop or get worse. A doctor can help determine the cause and provide treatment for the lesions.

The exact cause of skin issues related to Crohn’s disease is still not known, but connections between autoimmune disorders may be the underlying cause. Researchers continue to look into how Crohn’s disease rashes occur as well as new treatment methods.