Pityriasis Rosea (PR) is an acute inflammatory and self-limiting skin disorder, sometimes with troublesome symptoms. It begins as a solitary thin oval scaly plaque called a herald patch, and is typically asymptomatic.  PR is common among patients visiting dermatologists. The incidence of varies from 0.39 to 4.80 per 100 dermatological patients. There are a number of studies in favour of an infectious etiology for this disorder, and now it is believed that PR is induced by some of the Human Herpes Virus members, mainly HHV7 and HHV6. The association of human herpesvirus 6 (HHV-6) and HHV-7 with pityriasis rosea suggests that systemic drugs directed against HHV may hasten recovery of patients with pityriasis rosea. To date, there are few treatments available for this disorder. Ehsani A. et al. conducted a study at a university in Tehran, Iran to compare the efficacy of high dose acyclovir on the period and signs of pityriasis rosea.  There is no such clinical trial conducted in India, yet and this is why, we intend to conduct this study in a tertiary care institution like ours.

Our objective was to evaluate the effectiveness and safety of acyclovir in the treatment of pityriasis rosea compared to standard treatment protocol with calamine lotion and cetirizine.

The institution-based observer blind randomised comparative clinical trial will be conducted in the Out Patient Department of Dermatology of Medical College and Hospital, Kolkata. All patients presenting with pityriasis rosea (as per inclusion criteria will be recruited in study). The study population will be randomized by computer generated random numbers into two parallel groups group A, B with group A receiving Tablet acyclovir 400mg three times daily along with standard care of calamine lotion and Tablet Cetirizine 10 mg at bed time, group B receiving calamine lotion and Tablet Cetirizine 10 mg once daily. Simple randomised sampling would be done with allocation ratio of 1:1. The recruitment target is of approximately 12 subjects per group. The observer will be a dermatologist unaware of the randomisation allocation of the study drugs who will be assessing the effectiveness and safety parameters at each visit and thus blinded. There will be four weekly follow-ups where the effectiveness and safety parameters will be recorded.

The primary effectiveness parameter are the assessment of symptoms (Symptom score) on a 0-10 scale which includes new lesion appearance, pruritus grade, lesion features like erythema, scaling, number of lesions. Safety parameters will be the spontaneously reported adverse events and those elicited by the clinicians.