Crohn’s disease is a type of inflammatory bowel disease (IBD). It is a long-term, or chronic, condition that causes inflammation in the digestive tract. It can also cause skin issues, such as rashes.

Crohn’s disease pictures can help a person identify complications of the condition and pursue the right treatment.

About 40% of people with Crohn’s disease have non-digestive symptoms, most commonly affecting the skin.

In about 25% of all cases, these symptoms appear before a person receives a diagnosis or even before they experience digestive symptoms.

This article describes and explains Crohn’s disease symptoms on the skin by type.

A typical Crohn’s disease rash causes lesions of flushed skin due to chronic inflammation. The rash can look like swollen blisters, which may appear in groups or as a single lesion.

Erythema nodosum

One of the most common rashes due to Crohn’s disease is erythema nodosum. It can cause painful, swollen lumps to appear on flushed skin, and it usually develops on the legs, typically below the knees.

This rash has many possible causes, including bacterial and viral infections. Therefore, it is important for people to consult a doctor to get the right diagnosis.

Learn about how to treat erythema nodosum.

Other skin disorders

Some other types of rashes and skin symptoms that people with Crohn’s disease may develop include:

  • Skin tags: These are small growths of extra skin that may be flesh-colored, pink, or darker than the skin. Some people think they resemble moles. Skin tags are common near the anus.
  • Vasculitis: This group of diseases refers to a type of inflammation in blood vessels that may cause spots of flushed skin or broken capillaries.
  • Pyoderma gangrenosum: This skin condition is common among people with Crohn’s disease who experience skin disorders. It causes painful, swollen blisters that may break open and become ulcers. They often grow over time.
  • Medication-related lesions: Some individuals develop blisters on their skin as a side effect of Crohn’s disease treatment. This is because the treatment weakens the immune system, which in turn may increase the risk of skin infections.
  • Oral lesions: Some people with Crohn’s disease develop blisters or sores in their mouth. Others develop gum disease. About 10% of people with the condition develop issues with the skin in their mouth.
  • Vitiligo: Occasionally, IBD can have a link with vitiligo, which is a loss of pigment in the skin.
  • Psoriasis: This condition causes skin to become scaly, itchy, flushed, or inflamed.

For most Crohn’s skin lesions, treatment focuses on reducing Crohn’s-related inflammation by using disease-modifying agents, such as biological drugs.

In some cases, a person might need additional treatment, such as dental care, removal of skin tags, or antibiotic treatment for an infected blister.

A doctor may use a dermatoscope to examine the skin and reach a diagnosis.

Learn about what a dermatoscope might see.

It is rare for Crohn’s disease to affect the vulva or vagina, but it is possible.

If it happens, a person may notice the following:

  • swelling of the labia
  • nearby sore-like tunnels, known as fistulas
  • painful blisters, sores, or lesions on the vagina

Doctors treat this condition with drugs to manage inflammation from Crohn’s disease. A doctor can also surgically remove painful or large skin growths.

Learn about other causes of female genital sores.

Perianal Crohn’s disease means that a person has inflammation in or around the anus.

Examples of symptoms a person may experience include:

  • Abscesses: Some people develop small pockets of infection. An abscess may look like a very swollen pimple or feel like a painful lump under the skin.
  • Fissures: A fissure is a tear in the skin of the anus. It may cause symptoms similar to those of a hemorrhoid, such as pain and bleeding. A person may notice a patch of flushed skin, but it may also be too deep in the anus to see.
  • Stenosis: Sometimes, inflammation from Crohn’s disease causes the anus to become very narrow. A person may notice that their anus looks small, tight, or unusual and that it is painful or impossible to have a bowel movement.

Learn about the causes of rectal pain.

Anal skin tags

Some people with Crohn’s disease develop anal skin tags.

Skin tags feel like fleshy, loose lumps. They can be as small as a freckle or larger than a pencil eraser tip. They may be skin-colored, but they may also be darker or lighter than a person’s skin.

Skin tags are no cause for concern. However, they can snag on clothing or other objects and bleed or become infected as a result.

If an infection develops, it is important for a person to seek treatment. A doctor may also remove skin tags.

Orofacial Crohn’s disease affects the face, mouth, or both. It may be more common in children than in adults.

Some symptoms include:

Anti-inflammatory Crohn’s treatments may be effective. Doctors may also recommend prescription mouthwashes, special diets, or additional dental care to prevent severe gum health issues.

Crohn’s disease causes inflammation in the intestines and digestive tract. This can make it more difficult for the body to absorb nutrients from food.

Some stool changes a person may notice, especially during a Crohn’s flare, include:

  • Watery stools: More difficulty absorbing water and nutrients can cause diarrhea. A person may have more frequent or very loose bowel movements.
  • Constipation: Inflammation, especially of the anus and rectum, can make it more challenging to pass a stool. This, in turn, may cause constipation. A person may notice their stools are very hard or come out in small clumps.
  • Blood in the stool: Anal fissures or constipation may cause traces of red blood in the stools. Any bright red blood from Crohn’s is a medical emergency. Dark, tarry stools indicate that a person may be bleeding higher in the gastrointestinal tract, which is also a medical emergency.
  • Mucous in the stool: A person may notice that their stools contain streaky mucous or mucous that covers the stool completely. This can happen when the body is not able to absorb fat-soluble nutrients properly, which triggers the body to make more mucus to protect the inner intestinal lining and make it easier to pass stool.
  • Fatty stools: When the body cannot absorb nutrients such as fat, a person’s stool may look fatty or more slimy than usual.

It may be difficult to self-diagnose Crohn’s disease because many other conditions can produce similar symptoms. Those conditions can include:

Associated skin conditions

Skin symptoms that are due to Crohn’s disease are also common in many other conditions.

A doctor needs to examine the skin to rule out:

Crohn’s disease is treatable. However, without treatment, it can lead to serious complications.

A person should contact a doctor if:

  • they have symptoms of Crohn’s disease, such as frequent diarrhea or stomach pain
  • the symptoms do not improve with Crohn’s treatment
  • they develop new Crohn’s symptoms
  • they think they may have a skin infection
  • they cannot eat or drink without experiencing severe diarrhea

Learn more about the symptoms of Crohn’s disease.

Crohn’s disease is a chronic condition, and doctors have not yet discovered a cure.

For many people, symptoms will change or progress with time, and skin symptoms may be part of their experience.

However, with the right treatment, it is usually possible to reduce the severity of symptoms or even send the disease into remission.