Efficacy of phototherapy in pityriasis lichenoides chronica of dark skin: A retrospective study from a tertiary center in Mexico

Narrowband ultraviolet B phototherapy for pityriasis lichenoides: A real-life experience

INTRODUCTION

Pityriasis lichenoides (PL) is a papulosquamous disease affecting both children and adults, for which narrowband-UVB (NB-UVB) phototherapy is regarded as a commonly used treatment option. The aim of this study was to investigate the efficacy of NB-UVB phototherapy in the management of PL and to compare response rates in pediatric and adult age groups.

MATERIALS AND METHODS

This observational, retrospective study included 20 PL patients (12 pityriasis lichenoides chronica; PLC, 8 pityriasis lichenoides et varioliformis acuta; PLEVA) who failed to respond to other treatment modalities. The data for this study were collected retrospectively from patient follow-up forms in the phototherapy unit.

RESULTS

A complete response (CR) was obtained in all pediatric patients with PL, while 53.8% of adult patients had achieved CR. The mean cumulative dose required to achieve the CR was higher in pediatric patients than adult patients with PL (p < .05). The CR was achieved in 6 (75%) of 8 PLEVA patients, while 8 (66.7%) of 12 PLC patients had reached to CR. The mean number of exposures for patients with PLC to achieve a CR was higher than patients with PLEVA (p < .05). Erythema was the most common adverse effect during phototherapy particularly in 5 (35.7%) of the patients with PL who had achieved CR.

CONCLUSIONS

NB-UVB is an effective and well-tolerated treatment option for PL especially in diffuse types. A higher response can be obtained in children with higher cumulative dose. Patients with PLC may require more exposures for CR than patients with PLEVA.

Oral erythromycin in pityriasis lichenoides chronica and pityriasis lichenoides et varioliformis acuta

Pityriasis lichenoides (PL) is an uncommon cutaneous disorder. Oral erythromycin is proposed to be effective in treating the disease. Here, we reported 16 pediatric patients with PL and systematically reviewed published literatures on erythromycin treatment response in pediatric PL patients, to observe the different treatment response to erythromycin in the pityriasis lichenoides chronica (PLC) and the pityriasis lichenoides et varioliformis acuta (PLEVA) groups. Sixteen patients, 8 with PLC and 8 with PLEVA, were treated with erythromycin. In the PLC group, 25% (n = 2) patients responded to erythromycin, while in the PLEVA group, 87.5% (n = 7) patients responded to erythromycin. The response rate was higher in the PLEVA group than the PLC group (P =.05). No side effect was reported in the 16 patients. A total of 34 children including 16 from our studies were included for further descriptive analysis, in which 12 had PLC and 22 had PLEVA. In the PLC group, 41.7% (n = 5) of patients responded to erythromycin while in the PLEVA group, 90.9 % (n = 20) of patients responded. The response rate was higher in the PLEVA group than the PLC group (P = .004). In conclusion, erythromycin is effective and safe in the treatment of children with PL, and erythromycin was more effective in patients with PLEVA than PLC.