الفهرس 
Pityriasis roseaOnly 14 pages are availabe for public view
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Abstract
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.
Numerous hypotheses have been suggested as infective agents such as viruses, bacteria, spirochetes, and noninfective etiologies such as atopy and autoimmunity.
Atopy is a predisposition to respond immunologically to diverse antigens/allergens, leading to CD4+ Th2 differentiation and overproduction of immunoglobulin E (IgE).
The purpose of this study was to examine the association between pityriasis rosea and atopy by comparing a group of clinically diagnosed pityriasis rosea patients and a control group of healthy individuals regarding atopic personal & family history and atopic manifestations. Furthermore, measuring IgE levels, applying Hanifin and Rajka criteria of atopic dermatitis and conducting skin prick tests to detect reactivity to various environmental and food allergens.
Our study showed no significant difference between cases and controls regarding personal or family history of atopy, atopic dermatitis or total IgE levels. Furthermore, 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.
The association between pityriasis Rosea and atopy is yet to be identified and further investigated.