Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) associated with pemphigoid nodularis: a case report and review of the literature.

The immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) is a rare disorder caused by mutations of the FOXP3 gene. The FOXP3 gene encodes a DNA-binding protein of the forkhead/winged-helix family and is the central controller of the development of CD4+CD25+ regulatory T cells. CD4+CD25+ regulatory T cells help prevent autoimmune disease; a deficiency of these cells causes increased immunologic reactivity and autoimmunity. We describe a 14-year-old boy with IPEX syndrome confirmed by mutation analysis of the FOXP3 gene. The patient had chronic dermatitis and later developed bullous pemphigoid. He subsequently formed diffuse prurigo nodularis-like lesions resistant to multiple topical and systemic immunosuppressive medications. These lesions were confirmed by biopsy, direct immunofluorescence, and enzyme-linked immunosorbent assay of the 180 kd bullous pemphigoid antigen to be pemphigoid nodularis. He recently responded to rituximab, allowing discontinuation of his oral prednisone.