What do alopecia (hair loss) and Crohn’s disease have to do with each other? Alopecia isn’t a direct symptom of Crohn’s disease, yet up to one-third of people with Crohn’s experience it.

Hair loss in people with Crohn’s could be a side effect of certain Crohn’s medications used to treat it. Or it may be a symptom of an overlapping medical condition, a nutritional deficiency, or stress on the body from the disease. Certain types of hair loss are only temporary, but others involve lifelong cycles of growth and fallout.

Read on to learn more about hair loss related to Crohn’s, why it happens, and when it’s time to talk to a doctor about symptoms.

What Is Crohn’s Disease?

Crohn’s disease is a type of inflammatory bowel disease (IBD), a group of gastrointestinal (stomach and intestines) autoimmune diseases that cause digestive problems. Crohn’s can cause inflammation (irritation and swelling) in different parts of the digestive system, depending on the person. The most commonly affected area is where the small intestine transitions to the large intestine.

Healthcare professionals aren’t sure what causes Crohn’s disease, but they believe it may be genetic (passed down by family members). About 1 in 5 people with Crohn’s has a family member with the disease.

Health experts also think the immune system plays a role. In Crohn’s, your immune system mistakenly attacks healthy cells in the digestive system. When the immune system attacks the body, it’s considered an autoimmune issue.

Crohn’s disease can be mild or severe. While some people experience periods of remission without symptoms, there’s no cure at this time. Typical symptoms include:

• Stomach pain
• Diarrhea
• Fatigue
• Fever
• Mouth sores
• Nutrition absorption issues
• Blood in poop
• Loss of appetite
• Weight loss

How Alopecia Is Related to Crohn’s Disease

Growing research is looking into the relationship between Crohn’s disease and types of hair loss, including alopecia areata and telogen effluvium. Here’s what studies have found so far.

Alopecia Areata

Alopecia areata is an autoimmune condition where the immune system attacks hair follicles. It mainly causes circular patches of hair loss. Some people may only have a few patches of hair loss, while others may have widespread hair loss affecting the whole body. Hair loss and regrowth are unpredictable. Some people regrow hair without further hair loss, while others may cycle through hair growth and loss throughout their lives.

No one is sure what causes alopecia areata, but researchers know it’s genetic. An illness or environmental factor may trigger the gene. Additionally, about 25 percent of people with an existing autoimmune issue tend to develop others. According to a large 2021 study, IBD and alopecia areata seem to be strongly linked, although more research is needed to understand why.

A type of biologic (a common class of medications used to treat Crohn’s) called anti-tumor necrosis factor (anti-TNF) inhibitors is also linked to alopecia areata. One study found that those with IBD who took anti-TNF inhibitors were more likely to develop alopecia areata (5 percent to 15 percent of study participants) than those with IBD who didn’t take it. Research is mixed about how common hair loss is as a side effect, but right now, it’s considered uncommon.

Telogen Effluvium

Telogen effluvium is a term for temporary shedding, usually on the scalp. It’s often caused by a trigger, including stress, major body changes (like childbirth or menopause), and health issues. Once the body experiences a trigger, people may notice up to three times their normal shedding. Once the trigger is gone, hair usually grows back over time.

Some Crohn’s symptoms and treatments overlap with common telogen effluvium triggers. For example, fever and weight loss can be symptoms of Crohn’s as well as potential triggers of telogen effluvium. Some people who don’t respond to lifestyle changes and medications to manage Crohn’s may need surgery, which is also a possible trigger for telogen effluvium.

Some people with active Crohn’s disease experience inflammation that can affect how the body absorbs nutrients from food. These people may be at risk for hair loss from nutritional deficiencies, meaning they have less of the vitamins and minerals that the body needs to function properly. Vitamin A, D, E, K, and B12 levels may be most affected in those with Crohn’s. Of those, vitamins A, D, and B12 may contribute to hair health.

Research supports vitamin D supplements for hair loss in those with deficiencies, with mixed results on the benefits of vitamin A, E, and B12 supplements. Some people may also have difficulty absorbing protein and iron. These nutrients are important for supporting hair health and preventing telogen effluvium. Always consult your doctor before starting supplements to make sure they’re safe and appropriate for your health needs.

Other Causes of Hair Loss

Certain medications used to treat Crohn’s disease may cause hair thinning as a side effect. This is different from the link between biologics and alopecia areata.

For example, methotrexate is an immunosuppressant (a drug that lowers immune system activity) that can be used to treat Crohn’s. But methotrexate can cause many side effects like shedding or, on rare occasions, anagen effluvium (severe hair loss).

Crohn’s disease can also overlap with other health conditions associated with hair loss. These include thyroid disorders and systemic lupus erythematosus. If you’re concerned that another medical condition may be causing hair loss, talk to your doctor about your symptoms.

Steps Toward Managing Hair Loss

If you have Crohn’s disease and are experiencing constant, sudden, or patchy hair loss, talk to your doctor. Hair loss could signal an overlapping health condition or a reaction to a trigger. Your doctor can help you find the root cause and develop a treatment plan — or adjust your existing one — to prevent more hair loss.

Here’s what you can ask about:

• Controlling symptoms — If you’re experiencing frequent Crohn’s disease flares or severe symptoms, like fever and weight loss that can trigger hair loss, talk to your doctor. They may look into adjusting your treatment plan.
• Testing for nutrition deficiencies — Your doctor can run tests to see if you’re missing key nutrients and create a treatment plan to address it. Don’t start supplements until you’ve discussed your health needs.
• Changing medications — Ask your doctor if your current medications include hair loss as a side effect. Don’t stop your current medication before discussing options with your doctor.
• Managing stress — Crohn’s disease can be painful and limiting, and symptoms can greatly impact your quality of life. Ask your doctor about mental health resources and ways to manage symptom-triggering stress.
• Addressing other autoimmune issues — Ask your doctor about your risk of autoimmune diseases that may cause hair loss, including alopecia areata. Be ready to answer questions about your family history of autoimmune conditions.

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