Concurrent cytomegalovirus and herpes simplex virus infection in pemphigus vulgaris treated with rituximab and prednisolone.

Cytomegalovirus (CMV) is a well-known opportunistic infection in immunocompromised hosts (1, 2). Cutaneous CMV infection has rarely been described and has variable clinical presentations (1–3), especially in patients with autoimmune bullous disease. A 76-year-old man presented with a 1-month history of multiple vesicles and erosions. A diagnosis of pemphigus vulgaris was made by histopathology of intraepidermal vesicles, indirect im-munofluorescence (IIF) examination of deposition of intercel-lular substance (ICS) antibody over epidermis (1:160 positive), and enzyme-linked immunosorbent assay (ELISA) of positive desmoglein 1 and 3 antibodies (185 U and 147 U, respectively, MBL, Nagoya, Japan). He was treated initially with oral pred-nisolone, 90 mg daily, and topical 0.05% clobetasol propionate. We also planned to give 4 doses of weekly rituximab 500 mg infusion, but he received only 2 doses due to rituximab-related anaemia and thrombocytopaenia. Subsequently, he had no new blisters and most of the lesions healed gradually. His treatment course was complicated with bacteraemia and pneumonia, and the dose of prednisolone was tapered to 20 mg daily. However, after 6 weeks of oral and topical corticosteroid treatment, the lesions stopped healing and dry, yellowish necrotic tissues were noted on the previous unhealed erosions over his lower back, left shoulder and abdomen (Figs 1A and B). A skin biopsy from these lesions showed focal suprabasal acantholysis, epidermal ulceration, upper dermal necrosis, and perivascular infiltration of lymphocytes with nuclear dusts. A few enlarged histiocytic cells with large nuclei, some with in-tranuclear and intracytoplasmic inclusions suggestive of CMV infection were seen in the underlying skin adnexal epithelium (Fig. 2A). In addition, some acantholytic keratinocytes multi-nucleated with ground glass nuclei and marginated chromatin suggestive of herpes virus infection were found (Fig. 2B). The enlarged histiocytic cells showed positive immunostaining for CMV antigen (Fig. 2C). The swab culture grew herpes simplex virus (HSV)-1, and the tissue culture was negative for CMV and HSV. CMV immunoglobulin G (IgG) was positive, but CMV IgM was negative. The viral load was 1.63 × 10 5 copies/ ml. He had no evidence of other organ involvement, such as eye, lung, or gastrointestinal tract. The prednisolone dose was tapered to 10 mg daily, and a he was put on a 10-day course of valacyclovir, 3 g daily. Serial CMV viral load decreased gradually , and repeated testing for CMV IgM remained negative. His lesions started to re-epithelialize thereafter (Fig. 1C). The time-course of pemphigus disease area index, medications, body surface area …