Phototherapy in atopic dermatitis: a systematic review of the literature.

BACKGROUND: Phototherapy is a treatment option for atopic dermatitis recommended by several guidelines. OBJECTIVE: To perform a systematic review of the efficacy of different modalities of phototherapy and photochemotherapy in moderate to severe atopic dermatitis. MATERIAL AND METHODS: We considered all randomized clinical trials (RCTs) performed in patients with atopic dermatitis, and accepted all outcome measures. Articles were identified via an online search of the MEDLINE (via Ovid) and Embase databases and the Cochrane Central Register of Controlled Trials. We also searched for clinical trials registered in Current Controlled Trials and in the World Health Organization's International Clinical Trials Registry Platform. RESULTS: Twenty-one RCTs (961 patients) were included in the qualitative analysis. Two of the trials included children and adolescents (32 patients). The efficacy of narrow-band UV-B and UV-A1 phototherapy was similar for the different outcome measures contemplated. Two RCTs assessed the efficacy of psoralen plus UV-A therapy (PUVA). No serious adverse events were described. In general, the publications reviewed were characterized by a high risk of bias and poor reporting of methodology and results. CONCLUSIONS: There is evidence for the use of narrow-band UV-B and UV-A1 phototherapy in moderate to severe atopic dermatitis. Evidence supporting the use of PUVA in atopic dermatitis is scarce and there is little information on the use of phototherapy in childhood. For the purpose of future studies, it would be advisable to use comparable criteria and scales for the evaluation of disease severity and patients, to standardize radiation methods, and to establish a minimum follow-up time.

Fotoferese extracorpórea / Extracorporeal photopheresis

Fotoferese extracorpórea é uma modalidade de terapia celular que tem demonstrado eficácia e segurança em pacientes portadores de doenças auto-imunes e mediadas por células T, incluindo esclerodermia, linfoma de células T cutâneo/ Síndrome de Sézary e doença enxerto-contra-hospedeiro após transplante de células-tronco hematopoiéticas. Tem sido empregada, ainda, com o intuito de induzir tolerância em transplantes de órgãos sólidos. O tratamento se baseia no efeito biológico de uma substância fotossensibilizante, o 8-metoxipsoraleno, e da radiação ultravioleta A, nas células mononucleares coletadas por aférese e reinfundidas ao paciente. O mecanismo de ação parece ser devido à indução de imunidade anticlonotípica direcionada a clones patogênicos de células T. O tratamento induz a apoptose de células T patogênicas, e a ativação de células apresentadoras de antígenos desempenha papel importante no processo imunomodulador.

Extracorporeal photopheresis is a method of cell therapy that has demonstrated efficacy in autoimmune diseases, cutaneous T-cell lymphoma/Sézary syndrome and graft-versus-host disease after hematopoietic stem-cell transplantation. This technique has also been employed as a treatment strategy to induce tolerance after solid organ transplants. Treatment is based on the biological effect of ultraviolet A radiation and a photosensitizing drug, 8-methoxypsoralen, on mononuclear cells collected by apheresis and reinfused into the patient. The suggested mechanism of action is related to the induction of anticlonotypic immunity directed against pathogenic clones of T lymphocytes. Treatment induces apoptosis of pathogenic T-cells, and it appears that activation of antigen-presenting cells has an important role in this process.