Association between Pityriasis Rosea and Atopy

Abstract Background: Pityriasis rosea (PR) is a common, self-limiting, inflammatory papulosquamous skin disease. Although the exact pathogenesis of PR remains unknown, many studies have established a role for systemic active human herpesvirus (HHV) 6 and HHV-7 infection in the pathogenesis of PR based on the detection of HHV-6 and HHV-7 DNA in plasma and by electron microscopy in skin lesions PR. Aim of Study: To examine if pityriasis rosea is associated with atopy. Patients and Methods: A case control study was done to examine association between pityriasis rosea and atopy. The study included 40 patients diagnosed clinically with pityriasis rosea. All patients were attending at dermatology outpatient clinic at El-Demerdash Hospital Ain Shams University. The work was done between 1st of November 2021 and 15th of July 2022. Results: Our study showed no significant difference between cases and controls regarding personal or family history of atopy, atopic dermatitis or total IgE levels. Further-more, there was also no significant difference between cases and controls regarding age or sex. Skin Prick Test however showed not only a significant difference between cases and controls regarding number of allergens, with 48.8% of controls having 3 or more allergens compared to 16.1% of cases but also regarding the type of allergen where candida was found to be the commonest allergen among controls (40%) compared to 17.7% of cases. Conclusion: The association between pityriasis Rosea and atopy is yet to be identified and further investigated.