Pityriasis Rosea With Multiple Herald Patches Resulting in a V-shaped Pattern and a Christmas Tree Distribution

Abstract

Pityriasis rosea (PR), a benign and self-limiting skin disorder, typically manifests as a single initial lesion known as the herald patch. The herald patch is commonly followed by the development of secondary erythematous papules and plaques, aligning with Langer's lines to form a specific distribution pattern, resembling a Christmas tree on the back and a V-shaped pattern on the upper chest. Therefore, diagnosing PR may not be difficult based on its typical clinical presentation. In contrast, cases of atypical PR presentation have been reported, encompassing several differential diagnoses. Here, we present a case with multiple herald patches that needed differentiation from ringworm, syphilis, and erythema annular centrifugum. Subsequently, our case was diagnosed with PR, as the patches formed a V-shaped pattern and a Christmas-tree distribution.

Keywords: christmas-tree distribution; herald patches; human herpesvirus; pityriasis rosea; v-shaped pattern.

Figure 1. Clinical presentation

The photograph at presentation showed oval and annular erythematous papules on his chest, abdomen (a), and back (b). One week after presentation, the lesions showed a V-shape pattern on his upper chest (c) and a Christmas-tree pattern on his back (d). Three weeks after the presentation, the lesions on his chest, abdomen (e), and back (f) improved.