Crohn’s Disease (CD) is a chronic inflammatory bowel disease that primarily targets the gastrointestinal tract, though its effects extend throughout the body. Patients frequently experience symptoms beyond the digestive system, including joint pain, skin issues, and fatigue. A common concern for those managing CD is the possibility of hair loss or significant thinning. CD can lead to increased hair shedding, and understanding the relationship between chronic inflammation and hair follicle health is important for management.
How Crohn’s Disease Affects Hair Growth
Active Crohn’s disease interferes with the hair growth cycle through two systemic problems: chronic inflammation and nutritional deficits. Hair follicles are sensitive to the systemic stress caused by an inflammatory flare. Heightened inflammation often triggers Telogen Effluvium, a temporary shedding condition. This condition pushes hairs prematurely from the growing phase (anagen) into the resting phase (telogen), resulting in noticeable thinning across the scalp two to three months after a major flare-up.
Inflammation within the gut lining severely compromises the body’s ability to absorb nutrients. Damage to the intestinal wall, combined with frequent diarrhea, prevents the proper uptake of vitamins and minerals needed for hair growth. Deficiencies in several micronutrients are associated with hair loss in CD patients. Iron deficiency, often leading to anemia due to malabsorption or chronic intestinal blood loss, is a frequent trigger for hair thinning.
Zinc plays a significant part in hair follicle function, and its deficiency is common due to impaired absorption in the inflamed small intestine. Vitamin B12 malabsorption is also a concern, especially when inflammation affects the terminal ileum, the section responsible for its uptake. Insufficient levels of these micronutrients can directly disrupt the structure and growth of the hair shaft.
Protein and amino acids are the fundamental building blocks of hair, which is composed primarily of keratin. In cases of significant inflammation or poor appetite, Crohn’s patients can develop protein-energy malnutrition (PEM). When protein is low, the body prioritizes the limited supply for functions more immediately important than hair production. This diversion deprives hair follicles of the material they need, leading to weakened strands and increased shedding.
Medications That Impact Hair
While the disease is a cause of hair loss, some medications used to manage Crohn’s disease can also contribute to thinning as a side effect. Immunosuppressant drugs, such as methotrexate and thiopurines, slow down the immune system’s overactivity. Because hair follicles are among the fastest-dividing cells, this mechanism can inadvertently inhibit hair matrix cell division, leading to hair loss.
Methotrexate is known to interfere with folate metabolism; this side effect is uncommon but can sometimes be mitigated by taking folic acid supplements. Biologic therapies, such as TNF-alpha inhibitors, have a low incidence of hair loss. However, in rare instances, they can paradoxically trigger autoimmune hair conditions, such as alopecia areata or psoriatic alopecia.
Corticosteroids, such as prednisone, are often used to control severe inflammation during a flare-up. These drugs are not a common cause of hair loss and may temporarily improve hair health by reducing inflammation. However, a rapid reduction or withdrawal of the steroid dosage after high use can act as a sudden physiological shock. This abrupt change may trigger a delayed, temporary shedding episode weeks or months later.
Restoring Hair Health
The most effective strategy for reversing Crohn’s disease-related hair loss is achieving and maintaining disease remission. Reducing systemic inflammation through effective treatment stabilizes the hair cycle and allows follicles to return to normal growth patterns. Once inflammation is under control, the gut lining begins to heal, significantly improving the absorption of necessary micronutrients.
Targeted nutritional repletion is necessary to correct existing deficiencies. A healthcare provider can order blood tests to measure levels of iron, ferritin, zinc, and Vitamin B12. Based on these results, a patient may be prescribed high-dose oral supplements. In cases of severe malabsorption, they may require iron infusions or B12 injections to bypass the compromised gastrointestinal tract.
Working with a dietitian specializing in inflammatory bowel disease helps ensure the daily diet provides adequate protein and micronutrients, even during periods of low appetite. Sufficient protein intake is important, as it provides the amino acids needed for keratin production. If hair loss persists despite disease control and nutritional correction, a dermatologist can offer additional support, such as evaluating for other causes or suggesting topical treatments like minoxidil.