The third RCT demonstrated that acyclovir (400 mg 5 times a day for 5 days) reduced pain duration (by 0.9 day) but didn’t shorten healing time. If acyclovir was started during the prodrome, it decreased the time to disappearance of the lesion’s hard crust (2.1 days’ less time; P=.03), but the clinical significance of this finding is unclear.4
Topical treatment shows modest success
Two trials demonstrated that topical acyclovir (5% cream) modestly improved healing time and duration of pain (by as much as half a day). Patients in the first trial (paired RCTs reported together) began treatment within an hour of prodromal symptoms or signs, applying the medication 5 times daily for 4 days.5
Patients in the second trial used ME-609 cream (5% acyclovir plus 1% hydrocortisone), 5% acyclovir cream, or placebo, all applied 5 times daily for 5 days.6 Although the cream with acyclovir and hydrocortisone showed a slight benefit compared with placebo (lessening healing time by 0.8 day and pain duration by 1 day), it didn’t improve healing more than acyclovir alone. Other topical agents (penciclovir 1%; docosanol 10%) produced results similar to topical acyclovir.7,8
RECOMMENDATIONS
No national guidelines on this topic exist. An online resource notes that most patients don’t require treatment for mild self-limited HSL.9 For patients with prodromal symptoms, the authors recommend episodic oral antiviral therapy. Patients who have no prodome but multiple painful or disfiguring lesions may choose to use chronic suppressive therapy with an oral antiviral drug.