"Black box warning" rash with entecavir-case report

Background Hepatitis B infection is a significant worldwide health issue, predispose to the development of liver cirrhosis and hepatocellular carcinoma. Entecavir is a potent oral antiviral agent of high genetic barrier for the treatment of chronic hepatitis B infection. Cutaneous adverse reaction associated with entecavir has rarely been reported in literature. As our knowledge, this case was the first case reported on entecavir induced lichenoid drug eruption. Case presentation 55 year old gentlemen presented with generalised pruritic erythematous rash on trunk and extremities. Six weeks prior to his consultation, antiviral agent entecavir was commenced for his chronic hepatitis B infection. Skin biopsy revealed acanthosis and focal lymphocytes with moderate perivascular lymphocyte infiltration. Skin condition recovered completely after caesation of offending drug and short course of oral corticosteroids. Conclusion This case highlight the awareness of clinicians on the spectrum of cutaneous drug reaction related to entecavir therapy.