RESUMEN
BACKGROUND: Pityriasis lichenoides (PL) is a dermatologic disorder that manifests in either the acute (pityriasis lichenoides et varioliformis acuta) or the chronic form (pityriasis lichenoides chronica, also known as parapsoriasis chronica). Traditional first-line therapy consists of corticosteroids or antibiotics; however, these treatments are often accompanied with multiple side effects and may be ineffective. OBJECTIVE: The goal of this study was to review the use of phototherapy for treating PL in the pediatric population. MATERIALS AND METHODS: We performed a systematic review of the literature in the National Library of Medicine's PubMed database and the SCOPUS database discussing phototherapy for treatment of PL in the pediatric population. The following search terms were used: 'pityriasis lichenoides', 'pityriasis lichenoides chronica', 'pityriasis lichenoides et varioliformis acuta', and 'febrile ulceronecrotic Mucha-Habermann disease'. RESULTS: The systematic search and screening of articles resulted in 14 articles including a total of 64 patients with PL treated with phototherapy. Three different modalities were utilized, with five studies using broadband ultraviolet B (BB-UVB) radiation, nine studies utilizing narrowband UVB (NB-UVB), and two studies employing psoralen with ultraviolet A (PUVA) therapy. Overall, the use of BB-UVB had an initial clearance rate of 89.6 % with 23.1 % recurrence, whereas NB-UVB cleared 73 % of the lesions with no recurrence, and PUVA therapy initially cleared 83 % of the lesions with 60 % recurrence. The side-effect profiles were similar and revealed limited toxicity. CONCLUSION: Phototherapy shows promising results and a favorable side-effect profile in the treatment of PL. Ultimately, large randomized controlled trials are needed to determine optimal treatments.