Crohn's and hair loss
Crohn's and hair loss


Crohn’s disease usually presents with gastrointestinal symptoms such as stomach aches, diarrhoea and cramps.  Some symptoms are entirely separate from the digestive system such as mouth ulcers, fatigue and in some cases, there are no symptoms at all.

Studies have shown a link between hair loss and various types of inflammatory bowel disease.  Crohn’s has been specifically linked with alopecia areata, alopecia totalis and telogen effluvium.  Some hair loss in relation to Crohn’s can be a complication of prescription medication designed to reduce the symptoms of the disease.


Crohn’s disease is a long-term condition where some parts of the digestive system become inflamed.  Any part of the digestive system can be affected anywhere between the mouth and the anus.  In severe bouts of inflammation, bowel obstruction may occur.

Crohn’s disease is thought to be caused by several factors including, immune response, genetic predisposition, bacterial and environmental factors.  The inflammation that occurs is part of the defence mounted by the immune system to defend the gastrointestinal tract.

Whilst Crohn’s is an immune-mediated disease, it is not classed as an autoimmune disease because the inflammation is caused by an external trigger. Whilst the exact trigger leading to the immune response is unclear, it may be in part to do with immunodeficiency.

Increased intestinal permeability due to damage to the intestinal mucosal layer leads to activation of the innate immune system.  This results in large numbers of recruited neutrophils to clear bacteria and faecal bowel contents from the site of inflammation.  If the clearance attempt fails, bacteria and faecal matter becomes contained within the tissue leading to chronically inflamed granules of tissue.

It is thought that overcompensation for a slow and failing innate immune response leads to an overreactive adaptive immune response involving increased cytokine release from macrophages.  The remaining offending material trapped in the intestinal walls become subject to a virulent attack by the adaptive immune system.  The intestines will become infiltrated by large numbers of T-cells, these cells along with macrophages, will produce a large number of cytokines which further increase inflammation.

This defective response is seen throughout the body, so whilst Crohn’s disease describes and inflammatory disorder of the digestive system, there is a general abnormality in inflammation processes systemically. Symptoms will normally be associated with the entire gastrointestinal tract as there are larger numbers present than the rest of the body.

Around 50% of the overall risk of developing Crohn’s is due to genetics, over 70 genes have been associated with the disease.  Around 1 in 650 in the UK are affected by Crohn’s, males and females are affected equally and it can begin at any age.  Many people with the disease can suffer for a number of years before diagnosis due to the ‘patchy’ and irregular nature of the disease.

Crohn's and hair loss
Crohn's and hair loss


Crohn’s is diagnosed either by colonoscopy, X-ray, biopsies taken during a colonoscopy or by MRI scan.  There are certain characteristic features that determine Crohn’s, namely inflammation of the intestinal wall.

A colonoscopy is the ‘gold standard’ for making a Crohn’s diagnosis.  A colonoscopy allows the direct identification of the pattern if the disease through direct visualisation of the colon.  A colonoscopy can often reveal the cobblestone-like appearance of the intestines seen in around 40% of Crohn’s cases.  This is caused by areas of ulcerated tissue separated by health tissue.

X-rays can be used to image sections of the small intestine that cannot be reached by colonoscopy or structures of the colon that are too small.

Microscopic inspection of biopsies may show inflammation and infiltration of inflammatory cells such as neutrophils.  Biopsies may also show damaged intestinal villi due to chronic mucosal damage.  Key regulators of gut bacteria such as Paneth cells may also be affected.

MRI scans are especially good at detecting aspects of Crohn’s such as fissures, abscesses and inflammation of the intestines.  An MRI is particularly useful if the area affected is within the small bowel.

Crohn’s can be tricky to diagnose, and a number of tests are needed to make a certain diagnosis.  Conditions with similar clinical features include ulcerative colitis, irritable bowel syndrome, celiac disease and tuberculosis.


There are several reasons why hair loss can occur in patents with Crohn’s and other inflammatory bowel disorders:

High levels of cortisol | Increased levels of cortisol are common in patients with Crohn’s disease [1].   Whilst cortisol is a powerful moderator of the inflammation, it is a catabolic hormone.  When cortisol levels are consistently high normal metabolism and growth will be suppressed.

High levels of circulating cortisol leads to the breakdown of the collagenous structure that supports the hair follicle.  When collagen is broken down, the hair fibre will be less firmly anchored and the keratin cells within the hair fibre will go through a shorter hair growth phase leading to shorter hair that sheds prematurely.

Nutrition | Patients with Crohn’s often develop anemia due to impaired vitamin absorption.  Many patients have low B12, folate, iron deficiency or anemia of chronic disease.   Vitamin D and zinc levels are also often affected.

The keratin cells within a growing hair fibre require a number of vitamins and minerals to mature and grow.  A restriction in vitamins and minerals will give rise to weaker hair that may feel dry and brittle or break easily.

Gut bacteria imbalance | Patients with Crohn’s often have an imbalanced gut bacteria population.  Several studies have linked Crohn’s with reduced gut bacteria diversity. In active disease states, there is a definite and specific alteration in gut bacteria population.  In active disease there are a larger number of members belonging to Enterococus, Desulfovibrio, Fusobacterium, Haemphilus, Megasphaera, and Campylobacter.  When the disease is inactive, there are higher members of Roseburi, Christensenellaceae, Oscillibacter and Odoribacter.

Gut bacteria are responsible for many vital physiological processes such as protection against invading bacteria, the harvest of energy and the development of host immunity.  One study linked the gut bacteria to poor sulphur metabolism due to an increased levels of sulphate reliant bacteria using sulphur for metabolism producing hydrogen disulphide as a toxic metabolic by-product.

As sulphur is needed for extensive disulphide linkages in the growing hair shaft this can affect the quality of the linkages responsible for the strength of the hair fibre.  The increase of hydrogen sulphide in the inhibits the production of Acyl-COA dehydrogenase with is needed for butyrate oxidation.  Butyrate is a preferred energy source for the epithelial cells of the gut, it reduces inflammation, strengthens gut cell walls and lowers cholesterol [3].

The dysregulation of sulphur metabolism explains why most Crohn’ patients cannot tolerate foods such as raw onions and garlic.  The metabolism of sulphur containing amino acids needed for keratin production within keratin cells (cysteine and methionine) was also shown to be affected negatively when disease is active.

Medication side effects | Immunosuppressants that are prescribed for Crohn’s can interfere with hair growth as they are designed to slow down cell multiplication to deal with the inflammation in the bowel.  If you think your hair loss may be due to medication, you can talk with your doctor about changing your medication to one where hair loss is a less common side effect.


Crohn’s disease can cause hair loss, and while the condition itself cannot be cured, hair loss due to Crohn’s is usually reversible.

Get a blood test | Crohn’s can limit the absorption of vitamins and mineral in the gut.  Check if you may have an iron deficiency, low B12 or low levels of vitamin D.  Look at haemoglobin levels, folate and check your thyroid function.  Even if your blood test is ‘normal’ get it looked over by a hair loss expert who can pinpoint inadequacies in your blood profile that may impact your hair.

Avoid foods that will aggravate your condition | Avoid high sulphur containing foods (such as eggs, onions and garlic) that increase inflammation within your intestines and lower levels of gut protecting enzymes.  Some people with Crohn’s may find some types of carbohydrate lead to bloating and discomfort so it may be a good idea to opt for low fibre options such as white bread and white rice for easy digestibility.  Cutting out fried foods can reduce discomfort and uncomfortable bowel movements.

Increase zinc intake or take a supplement | A high zinc diet or supplementing over 15 mg of zing per day was shown to reduce risk of Crohn’s disease.  Zinc balances immune response to inflammation and increases the specificity and strength of the adaptive and innate immune response.  A study showed zinc administration reduced mucosa inflammation leading to a reduction of damage to the mucosal layer [4].

Higher levels of serum zinc are associated with lower levels of intestinal permeability and higher integrity of tight junctions [5].  Another study showed zinc supplementation resulted in lower levels of disease relapse [6].  Lahiri et al showed that increased levels of zinc led to increased bacterial clearance and engulfing of faecal matter [7].

Finally, zinc was found to regulate the inflammatory response further supporting the role of zinc in inflammatory bowel conditions such as Crohn’s [8].


Hair loss is a potential side effect of Crohn’s, but it need not be a long-term problem.  Your hair loss may be a sign that there are some other issues that need to be addressed alongside disease management.

Resolving your hair loss may take several months, but perseverance is key.  Your quest for healthier hair may lead to improved disease management and an improved nutritional status that improves your overall quality of life.


  1. Importance of Serum Cortisol Levels in Inflammatory Bowel Disease: 1197. Official journal of the American College of Gastroenterology| ACG, 101, p.S465.
  2. Integrated microbiota and metabolite profiles link Crohn’s disease to sulphur metabolism. Nature communications, 11(1), pp.1-15.
  3. Phylogenetic relationships of butyrate-producing bacteria from the human gut. Applied and environmental microbiology, 66(4), pp.1654-1661.
  4. Zinc sulphate solution enema decreases inflammation in experimental colitis in rats. Gastroenterological Hepatology. 1999 Nov; 14(11):1088-92.
  5.  Zinc deficiency induces membrane barrier damage and increases neutrophil transmigration in Caco-2 cells. Nutrition. 2008 Sep; 138(9):1664-70
  6. Zinc supplementation tightens ‘leaky gut’ in Crohn’s disease. Inflammatory Bowel Disease 2001;7:94–98
  7. Activation of pattern recognition receptors up-regulates metallothioneins, thereby increasing intracellular accumulation of zinc, autophagy, and bacterial clearance by macrophages.Gastroenterology. 2014 Oct; 147(4):835-46.
  8. ZIP8 regulates host defense through zinc-mediated inhibition of NF-kappaB. Cell Rep2013;3:386–400.