Introduction: Cutaneous metastatic Crohn's disease is a granulomatous inflammation of the skin that is noncontiguous to the gastrointestinal tract.
Case report: A 42-year-old man with Crohn's disease is admitted for antibiotic resistant erysipela-like dermo-hypodermitis. The presence of granulomatous lesions on skin biopsy, the absence of any infectious agent identified despite extensive investigations and the dramatic improvement observed with corticosteroid eventually lead to the diagnosis of cutaneous metastatic Crohn's disease.
Conclusion: During Crohn's disease, biopsy should be considered for every undiagnosed skin lesion as the characteristics of cutaneous metastatic Crohn's disease are not specific. The presence of a non caseous granulomatous dermal infiltration suggests the diagnosis and should make consider the initiation of corticosteroid and the discontinuation of others inappropriate therapeutics (i.e. surgical treatment, antibiotics).