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Inflammatory Comorbidity

HS and Crohn's Disease

Hidradenitis suppurativa and Crohn's disease share deep inflammatory roots and can be difficult to distinguish in the perianal region. Understanding the connection is critical for proper diagnosis and treatment.

Last reviewed: April 2026|10 min read

Medical disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before making changes to your treatment plan.

Key Takeaway

People with HS are approximately 10 times more likely to have Crohn's disease than the general population. Both conditions are driven by TNF-alpha and IL-23 inflammatory pathways, which means adalimumab - the only biologic FDA-approved for both - can treat both conditions simultaneously. If you have perianal HS with GI symptoms, ask for a gastroenterology referral.

Why They Co-Occur

Shared Inflammatory Pathways

HS and Crohn's disease are both immune-mediated inflammatory conditions. They share several key biological pathways that explain why they occur together far more often than chance alone would predict.

TNF-alpha Overproduction

Both HS and Crohn's disease are characterized by markedly elevated tumor necrosis factor-alpha (TNF-alpha), a master inflammatory cytokine. This shared pathway explains why adalimumab - a TNF-alpha inhibitor - is FDA-approved for both conditions. Blocking TNF-alpha reduces inflammation in both the gut and the skin simultaneously.

IL-12 and IL-23 Pathways

The IL-12/IL-23 axis drives Th1 and Th17 immune responses that are dysregulated in both Crohn's disease and HS. Ustekinumab, which blocks both IL-12 and IL-23, is approved for Crohn's and has shown promise in HS clinical trials. This shared pathway suggests a common immune dysregulation underlying both conditions.

Gut-Skin Axis

Emerging research on the gut-skin axis shows that intestinal dysbiosis (imbalanced gut bacteria) can drive systemic inflammation that manifests in the skin. Patients with both HS and Crohn's often have severely disrupted gut microbiomes. Probiotic interventions and dietary changes that restore gut health may benefit both conditions.

Follicular Occlusion and Fistula Formation

Both HS and Crohn's disease can produce fistulas - abnormal tunnels connecting body cavities. In HS, sinus tracts form between skin lesions. In Crohn's, fistulas form between loops of bowel or between the bowel and skin. In the perianal region, these can be clinically indistinguishable without imaging and biopsy.

Warning Signs

When to Ask About Crohn's Disease

If you have HS and experience any of the following symptoms, discuss Crohn's disease screening with your doctor. These symptoms warrant a gastroenterology referral, especially if you have perianal HS.

Rectal bleeding or blood in stool
Chronic diarrhea lasting more than 4 weeks
Abdominal pain or cramping, especially after eating
Unexplained weight loss
Fatigue beyond what HS alone explains
Perianal fistulas or abscesses
Mouth sores (aphthous ulcers)
Joint pain (arthralgia) in multiple joints
Treatment

Treatments That Address Both Conditions

Because HS and Crohn's share inflammatory pathways, several treatments are effective for both. A coordinated approach between your dermatologist and gastroenterologist is essential.

Adalimumab (Humira)

FDA-Approved Both

The only biologic FDA-approved for both moderate-to-severe HS and Crohn's disease. An ideal first-line biologic when both conditions are present. Administered by self-injection every 1-2 weeks.

Infliximab (Remicade)

Off-Label HS

A TNF-alpha inhibitor approved for Crohn's disease and used off-label for HS. Given by IV infusion every 6-8 weeks. May be preferred when IV administration is needed or when adalimumab has failed.

Ustekinumab (Stelara)

Emerging for HS

Approved for Crohn's disease; in clinical trials for HS. Targets IL-12 and IL-23. An option when TNF-alpha inhibitors have failed or are contraindicated.

Antibiotics (Rifampicin + Clindamycin)

Antibiotic

The standard antibiotic combination for HS is also used in Crohn's perianal fistulas. Reduces bacterial burden and inflammation in both conditions. Typically used for 10-12 weeks.

FAQ

Frequently Asked Questions

Related Articles

HS Comorbidities OverviewHS and AnemiaHS Treatments HubMedical TreatmentsUnderstand HS

References

  1. 1.van der Zee HH, et al. The association between hidradenitis suppurativa and Crohn's disease: in a dermatology department. Br J Dermatol. 2010;162(1):141-144. PubMed
  2. 2.Garg A, et al. Prevalence and co-morbidities of hidradenitis suppurativa in the United States. Dermatology. 2014;228(3):261-265. PubMed
  3. 3.Deckers IE, et al. Hidradenitis suppurativa is associated with a higher risk of inflammatory bowel disease: a population-based study. Br J Dermatol. 2017;176(3):755-758. PubMed
  4. 4.Alikhan A, et al. North American clinical management guidelines for hidradenitis suppurativa. J Am Acad Dermatol. 2019;81(1):76-90. PubMed
  5. 5.Kimball AB, et al. Adalimumab for the treatment of moderate to severe hidradenitis suppurativa. N Engl J Med. 2016;375(5):422-434. PubMed
  6. 6.Feuerstein JD, et al. AGA Clinical Practice Guidelines on the Management of Crohn's Disease After Surgical Resection. Gastroenterology. 2022;162(5):1434-1445. PubMed