Delayed hypersensitivity reaction resulting in maculopapular-type eruption due to entecavir in the treatment of chronic hepatitis B

Figure 1 Cutaneous eruption associated with entecavir that manifested after one week of therapy in a non-naïve patient with chronic hepatitis B. Coalescent erythema, intermingled with papules, was observed on the lower back.

Figure 2 Hematoxylin and eosin stained erupted skin biopsy sample. The epidermis is acanthotic with focal parakeratosis (arrows). A perivascular lymphocytic infiltrate admixed with interstitial eosinophils is present in the papillary and reticular dermis (arrowheads). Magnification: 200 ×.

Figure 3 Alanine aminotransferase and hepatitis B virus DNA levels following the course of various antiviral treatments. Entecavir (1 mg) treatment could not be continued past the 15^th day due to an adverse drug reaction (skin rash). ALT: Alanine aminotransferas; HBV: Hepatitis B virus; ADV: Adverse drug reaction; BT: Breakthrough; ETV: Entecavir; LAM: Lamivudine.

Figure 4 Cytokine release profile of peripheral blood mononuclear cells isolated from the patient during the cutaneous eruption associated with entecavir treatment. The level of secreted interleukin (IL)-4 was significantly elevated at 18 and 24 h after entecavir treatment. IL-4 is the representative cytokine of type 4b hypersensitivity.