The Overlap of Fixed Drug Eruption and Human Herpes Virus Type II Associated Erythema Multiforme

We present a 29-year-old woman who admitted to the outpatient clinic with a characteristic vesicular eruption of herpes labialis on her upper lip and erythematous, edematous plaques on her arms. She had a disease background of similar lesions that used to appear at the same sites and recurrences of herpes labialis, as well. Histopathologic examination of the biopsy material obtained from an erythematous plaque on the arm revealed necrosis and reticular degeneration, with sparse neutrophils and lymphocytes in the lumen of splitted epidermis. A perivascular infiltration composed of lymphocytes, sparse polymorphonuclear cells and eosinophils was present in the upper dermis which was in accordance with erythema multiforme. Herpes simplex virus type II DNA was detected on the skin biopsy of an erythematous plaque by polymerase chain reaction (PCR). The lesions of the patient healed after antiviral and oral corticosteroid therapy. Recurrences on the arms and face were noted after discontinuation of the treatment but some of them were leaving brownish macules which were characteristic for fixed drug eruption. After discontinuation of all drugs that the patient take, no further attack appeared.

In the present case it is noteworthy that histologically proven erythema multiforme coexisted by herpes simplex virus type II and additional eruptions were associating from time to time and showed a distinctive course by residual hyperpigmentation. HSV DNA has previously been demonstrated in epidermal cells of erythema multiforme lesions by in situ hybridization and polymerase chain reaction. Erythema multiforme may be provoked by some drugs and needs be differentiated from other types of drug eruptions.