Suppression of recurrent non-genital herpes simplex infection by prophylactic oral acyclovir

Following a primary infection with herpes simplex virus (HSV) some patients proceed to suffer repeated recurrences of the HSV infection. Whilst it has recently been shown that oral acyclovir taken prophylactically decreases the frequency of recurrent genital HSV infection (Douglas et al. , 1984; Mindel et al. , 1984; Straus et al. , 1984), to date there have been no reports of any form of effective prophylaxis against recurrent HSV infection on non-genital skin in immunocompetent patients. In order to determine if oral acyclovir could afford protection in such patients we have performed a double-blind, placebo-controlled, crossover trial of oral acyclovir in patients experiencing eight or more episodes of recurrent non-genital HSV infection per year.
Fourteen patients entered the trial and 11 completed the protocol. Only two patients experienced a recurrence during the 12-week treatment period with acyclovir (200 mg four times daily), compared with nine during placebo treatment ( P = 0016, sign test). Although lesion development was effectively suppressed in nine of the patients whilst taking acyclovir, the development of prodromal symptoms and occasionally erythema was reported by five. There was no difference between acyclovir and placebo in the time to first recurrence following completion of treatment. No patient reported any side-effects of either placebo or acyclovir therapy.
It is believed that this is the first report of any form of therapy which is effective in the suppression of the frequently recurring non-genital HSV infection in immunocompetent patients.