Mucocutaneous manifestation mimicking vasculitis in chronic hepatitis B: A case report

BACKGROUND Hepatitis B virus (HBV) primarily causes hepatic inflammation and has various clinical manifestations. However, extrahepatic reactions, ranging from localized or systemic inflammation, may occur in some cases. Here, we report a case of an acute exacerbation of chronic HBV infection with atypical extrahepatic manifestation confined to the skin and mucosa despite nucleotide analog treatment, which was fully recovered on systemic steroid treatment. CASE SUMMARY A 53-year-old woman visited a clinic due to worsening skin rash and mucosal inflammation. She was receiving antiviral therapy due to a recent acute exacerbation of chronic HBV infection. While liver function was improving with antiviral treatment, skin rash and mucosal inflammatory lesions gradually worsened. Thus, blood tests and skin biopsy were performed to determine the cause. Despite a thorough review of serum markers and skin biopsy results, a concrete diagnosis revealing other etiology apart from the acute phase of HBV infection could not be established. The cutaneous lesions were considered a rare immunologic extrahepatic manifestation of HBV, warranting systemic steroid treatment. Afterward, both skin and mucosal lesions rapidly improved, and the patient was discharged without any sequelae. CONCLUSION Clinicians should recognize mucocutaneous manifestations of chronic HBV, as systemic steroids may yield favorable outcomes.