Successful Treatment of Epidermolysis Bullosa Pruriginosa with Anti-IgE Therapy (Omalizumab): A Case Report and Four Years Follow Up

Importance: Epidermolysis bullosa pruriginosa (EBP) is a rare adult-onset heredo-familial skin disorder. Bullous skin lesions are triggered by intense pruritus, which is the hallmark of the disease. Eosinophilic infiltrates and elevated IgE levels in serum and lesions have been reported, but their pathological role is yet to be determined. Although treatment with anti-IgE therapy (Omalizumab) has been used successfully in autoimmune bullous diseases but not in EBP to our knowledge. Observation: We report a case of a 34-year-old female with adult-onset pruritic and blistering disease of the skin. Sub epidermal blisters with viable roofs and numerous epidermal neutrophils and eosinophilic infiltrate were detected histopathologically; however, the absence of IgA, IgG, IgM, C1q, and C3 deposits made the diagnosis of Epidermolysis bullosa acquisita and Bullous pemphigoid uncertain. Whilst testing for intra-lesional IgE autoantibodies was not performed, total and specific serum IgE concentrations increased during her illness in the absence of an allergic or parasitic disease. Because no improvement in her symptoms was observed with conventional treatments, whole exome sequencing was performed which showed a non-conservative Glycine substitution in the G2481D residue in the COL7A1 gene suggestive of EBP. Off-label use of anti-IgE drug (Omalizumab) was attempted due to severity of her symptoms and elevated levels of IgE. On initiating the treatment, the patient showed a significant improvement in her skin condition; however, a trial to taper off Omalizumab two years later was unsuccessful. Conclusion: This case suggests a possible role of IgE autoantibodies in EBP that requires further research, consolidated by the fact that our patient showed improvement with anti-IgE therapy. Furthermore anti-IgE therapy offers a possible new targeted treatment for EBP in the absence of curative treatments.