Hair Loss in Women with Crohn's Disease and Mirena IUD
In a woman with Crohn's disease using a Mirena IUD, hair loss is most likely multifactorial, stemming from nutritional deficiencies related to Crohn's disease (iron, zinc, vitamin D), the levonorgestrel in the Mirena IUD itself, and potentially medication side effects from Crohn's treatments.
Primary Causes to Investigate
1. Levonorgestrel IUD-Related Hair Loss
The Mirena IUD contains levonorgestrel, a progestin with androgenic activity that can directly cause alopecia. Hair loss is a recognized systemic side effect of the levonorgestrel IUD, with an estimated cumulative incidence of 0.33% in the first year 1. While this may seem low, it represents a real clinical phenomenon that should be considered 2. The androgenic properties of levonorgestrel can trigger androgenic alopecia in susceptible women 3.
- Hair loss typically presents as diffuse thinning
- May occur within months of IUD insertion
- Removal of the IUD should be considered if other causes are excluded and hair loss is distressing
2. Crohn's Disease-Related Nutritional Deficiencies
Measure iron studies (including ferritin), vitamin D, zinc, and thyroid function to identify treatable causes of hair loss 4. Women with Crohn's disease are at high risk for:
- Iron deficiency: Most common nutritional cause; aim for ferritin >40 mg/L, though some experts suggest >70 mg/L for optimal hair growth 4
- Zinc deficiency: Found in approximately 15% of women with hair loss 4
- Vitamin D deficiency: Present in up to 62% of women with female pattern hair loss 4
- Protein-calorie malnutrition: From malabsorption or active inflammation
3. Crohn's Disease Medications
Review current medications:
- Corticosteroids: Can cause telogen effluvium and Cushing syndrome-related changes 5
- Methotrexate: Known to cause hair loss as a side effect
- Thiopurines (azathioprine, mercaptopurine): May contribute to hair loss 5
4. Chronic Telogen Effluvium (CTE)
Active Crohn's disease creates a chronic inflammatory state that can trigger CTE—diffuse hair shedding without a specific pattern 4. This differs from female pattern hair loss by:
- Diffuse thinning across entire scalp (including occiput)
- Positive hair pull test from multiple scalp areas
- No miniaturization pattern on examination
Diagnostic Approach
Order the following laboratory tests immediately:
- Complete blood count
- Ferritin (target >70 mg/L for hair regrowth)
- 25-hydroxyvitamin D
- Zinc level
- TSH and free T4
- C-reactive protein and fecal calprotectin (to assess Crohn's activity)
- Total and free testosterone if androgenic features present 4
Clinical examination should assess:
- Pattern of hair loss (diffuse vs. frontoparietal/central pattern)
- Presence of follicular ostia (rules out scarring alopecia)
- Hair pull test from multiple scalp locations
- Signs of hyperandrogenism (acne, hirsutism)
- Scalp inflammation or erythema
Management Algorithm
Step 1: Optimize Crohn's Disease Control
Active inflammation impairs nutrient absorption and creates a catabolic state. Ensure Crohn's disease is in remission using treat-to-target principles 6, 7.
Step 2: Correct Nutritional Deficiencies
- Iron supplementation if ferritin <70 mg/L
- Vitamin D supplementation to achieve levels >30 ng/mL
- Zinc supplementation if deficient
- Consider nutritional consultation for protein optimization
Step 3: Address Medication-Related Causes
- Taper corticosteroids if possible 5
- Consider switching from methotrexate or thiopurines to biologics if hair loss is severe and these medications are implicated
Step 4: Consider IUD Removal or Replacement
If hair loss persists after correcting nutritional deficiencies and optimizing Crohn's control, consider removing the Mirena IUD and switching to a non-hormonal contraceptive method (copper IUD) or a contraceptive with lower androgenic activity 3, 1. The decision should weigh:
- Severity and psychosocial impact of hair loss
- Contraceptive needs and alternatives
- Benefits of Mirena for menorrhagia management (if applicable)
Step 5: Dermatology Referral
If hair loss continues despite above interventions, refer to dermatology for:
- Dermatoscopic examination to assess miniaturization 4
- Possible scalp biopsy if diagnosis unclear
- Consideration of topical minoxidil 5% (first-line treatment for female pattern hair loss) 4
Important Caveats
- Do not assume hair loss is solely from one cause—these factors often coexist
- The temporal relationship between IUD insertion and hair loss onset is critical; if hair loss began shortly after Mirena placement, the IUD is more likely culpable
- Note that one case report documented Crohn's disease exacerbation after Mirena insertion 8, though this is rare
- Correction of nutritional deficiencies may take 6-12 months to show improvement in hair regrowth
- Avoid attributing all symptoms to Crohn's disease without investigating other treatable causes