Background Topical or systemic antiviral drugs reduce the duration of herpes simplex virus 1 (HSV-1) recurrences but may not alleviate functional symptoms.
Objectives To assess the efficacy and safety of CS20 (Acura 24®) protective barrier gel versus topical aciclovir and placebo in resolving functional symptoms in HSV-1 labial recurrences.
Methods A prospective, randomized, single-centre, assessor-blinded study of CS20 versus topical aciclovir or placebo. The primary endpoint was the total score of four herpes-related functional symptoms (pain, burning, itching, and tingling sensations), evaluated by visual analogue scale (VAS). Secondary endpoints encompassed objective skin changes (oedema, crusting and erythema), evaluated by specific clinical scores.
Results In a study of 106 patients, compared with placebo, a significant improvement in total functional symptom score was observed after 1 day of treatment in the CS20 group, but only after 7 days of treatment in the topical aciclovir group. Burning sensations were significantly reduced by CS20 compared with aciclovir (Days 1–2) or placebo (Days 1–7). Compared to placebo, CS20 significantly reduced pain intensity on Days 1–6. CS20 induced significant and early improvements in the clinical scores for oedema and crusting compared with placebo. Time to cure was similar for CS20 and aciclovir. The treatments were well tolerated and adverse events were comparable in the three treatment groups.
Limitations The single-centre and single-blind design of the study and the preselection of patients.
Conclusion CS20 showed superior effectiveness against functional symptoms (pain and burning) associated with HSV-1 labial recurrences and was similar to aciclovir for time to cure.