Acydovir was evaluated as treatment of recurrent herpes simplex virus type 2 infection of the hand in a double-blind, placebo-controed crossover study. In nine fully evaluable patients, oral acyclovir (2 g/day in three doses for 10 days) initiated during the earlist phase of a recurrence reduced the mean durations (± standard deviation) of clinkal symptoms from 10.1 (±3.6) to 3.7 (±3.0) days (P = 0.008), signs from 11.1 (±3.7) to 6.2 (±3.3) days (P = 0.024), and viral positivity from 5.3 (+3.8) to 0.6 (±1.1) days (P = 0.011).Effective treatments for most human herpes simplex virus (HSV) infections have been well documented (7,(9)(10)(11)(12). However, recurrent HSV infection of the band, which can be frequent, painful, and cosmetically unacceptable, has attracted little therapeutic attention (1-3, 5, 6, 8). After an earlier uncontrolled observation, we evaluated in this double-blind, placebo-controlled crossover study the effects of early intervention with oral acyclovir on the durations of symptoms, signs, and virl culture positivity of recurrent HSV type 2 (HSV-2) infection of the hand (4).Fourteen patients (11 males and 3 females) with documented HSV-2 infection of the hand participated in a study that was approved by the University of Calgary Committee on Medical Bioethics. All the patients were between 18 and 50 years old and had between 2 and 12 recurrent infections per year. They were otherwise in good health with no evidence of any underlying immunodeficiency. All the females were using a recognized form of contraception and were not pregnant at the time of treatment.A double-blind, placebo-controlled crossover design was adopted in view of the limited number of eligible patients. Due to uncertainties about the bioavailability of acyclovir at the time of the study design, a high-dose regimen was selected. Active drug or placebo (provided by Burroughs Weilcome, Kirkland, Quebec, Canada) was randomized to either cycle A or B by a computer program. The patients were given written instructions and a bottle of 100 tablets (cycle A). They were advised to take four tablets when prodromal symptoms which they felt likely to result in HSV infection of the hand were first noticed, followed by two doses each of three tablets in a 24-h period. A total of 10 tablets per day in three doses was given for a total of 10 days. The patients were reviewed within 24 h of initiating therapy and then daily until the episode resolved. After the first course of therapy, the patients returned the cycle A bottle and were given a second bottle (cycle B) with identical instructions.The presence and severity of symptoms (pain, swelling, tingling, tenderness, and discomfort) and both local and systemic signs of infection (erythema, papule, vesicle, pustule, scab, lymphangitis, and lymphadenopathy) were recorded at each visit. analyzed by using within-patijnt paired t tests.