Acyclovir - the standard drug treatment against herpes - is ineffective against recurrent herpes, which is the most common form of the disease. The drug's main benefit is as a 'just-in-case', or prophylactic, remedy.
These findings, made by the Centre for Rural Health Studies in Newfoundland, Canada, are based on three major studies of the drug. The first study discovered that acyclovir was not helpful as a topical treatment during the acute phase of recurrent herpes labialis, and a randomized controlled trial the same year - 1991 - found it was hardly any better when used prophylactically. The second trial also found that oral acyclovir was only of marginal benefit in the acute phase of herpes, and it had no benefit if skin lesions had started to appear. A third trial showed that the painful period of herpes fell by 1.4 days if the patient had taken the drug beforehand.
One problem in treating the disease is that scientists are beginning to realize that herpes labialis comes in two types. The 'immediate' lesions - ones that appear within 48 hours - comprise about one-third of all herpes lesions, and do not respond to acyclovir; the 'delayed' lesions, which appear after three to seven days, seem more responsive to the drug.
Recurrent herpes labialis is one of the most common skin complaints seen by doctors; very few people see the doctor when they have the initial, and usually most painful, attack. Recurrent attacks are usually sparked by stress (BMJ, January 6,1996).