Clinical and Histologic Features of Pityriasis Lichenoides: The Difference between Children and Adults

Kim, Jun Ki; Lee, Ji Yeoun; Yoon, Tae Young

Abstract

BACKGROUND
Pityriasis lichenoides, an inflammatory skin condition of unknown etiology affecting both children and adults encompasses a clinical spectrum between pityriasis lichenoides et varioliformis acuta (PLEVA) and pityriasis lichenoides chronica (PLC). Although reported to follow a more self-limiting course in children compared with adults, there are a few studies comparing pityriasis lichenoides in both age groups in Korea.
OBJECTIVE
The aim of this study was to evaluate the clinicopathological features, overall efficacy of treatments, and disease outcomes in children and adults diagnosed with pityriasis lichenoides.
METHODS
This was a retrospective study of pityriasis lichenoides at our center between January 2003 and December 2013. Clinical manifestations and histopathological features of 54 patients with pityriasis lichenoides were analyzed. We also evaluated the clinical course in children and adults according to Gelmetti's classification.
RESULTS
In this study, 36 patients were children (mean age 11.6 years, range 3approximately18 years) and 18 patients were adults (mean age 34.7 years, range 19approximately55 years). Lesions on the face were observed more commonly in children (n=18, 50%) compared with adults (n=1, 5.5%). Of the clinical features, vesiculation, crust and pigmentary changes were significantly more common in children than in adults. After treatment, 12 children (33.3%) and 10 adults (55.6%) went into complete remission. Histopathological features were not significantly different between children and adults. They just showed the difference between PLEVA and PLC. Dyskeratosis, epidermal necrosis, intraepidermal red blood cell (RBC) trapping, and RBC extravasati on in the dermis were more prominent in PLEVA than in PLC. By Gelmetti's classification, disease duration was longer in children with the peripheral type (38.5 months) than in children with the diffuse and central types. In adults, the diffuse type lasted longer (24.5 months) than the central and peripheral types.
CONCLUSION
This study suggests that, compared with adults, pityriasis lichenoides in children is more likely to follow an unremitting course, with more facial/acral involvement and pigmentary changes and a poorer response to conventional treatment modalities. Applying the Gelmetti's classification, disease duration was longer in children with the peripheral type than other types. However, in adults, the duration was longer with the diffuse type.