AAFM Boards Dermatology Practice Test

Pityriasis rosea is a skin condition characterized by a distinctive rash that typically begins with a single large patch, called a "herald patch," followed by smaller patches. Although the exact etiology of pityriasis rosea remains unclear, research has indicated a potential association with human herpesvirus 6 or 7 (HHV-6 or HHV-7). This connection is supported by studies that have found viral DNA in skin lesions of patients with pityriasis rosea. Human herpesvirus 6 and 7 belong to the same family of viruses as herpes simplex virus but have distinct characteristics and effects. These viruses are known to cause other illnesses, such as roseola in children, which could explain the similar presentation in terms of a rash. The hypothesis that these viruses trigger pityriasis rosea is further supported by the pattern of outbreaks, often seen in particular seasons, resembling viral infections. The other viruses listed are either less closely related or have not been consistently linked to the development or exacerbation of pityriasis rosea. Thus, recognizing the association with human herpesvirus 6 or 7 helps in understanding the potential viral triggers for this condition.