The role of narrowband ultraviolet B phototherapy in the treatment of refractory osteomalacia

João Teixeira, Department of Dermatology and Venereology, Coimbra Local Health Unit, Coimbra, Portugal Ana Luísa Matos, Department of Dermatology and Venereology, Coimbra Local Health Unit, Coimbra, Portugal Duarte Flor, Department of Dermatology, Coimbra University Hospital Center, Coimbra, Portugal Francisco Martins, Department of Dermatology and Venereology, Coimbra Local Health Unit, Coimbra, Portugal Maria João-Cadório, Department of Rheumatology, Coimbra Local Health Unit, Coimbra, Portugal Mariana Luís, Department of Rheumatology. Coimbra Local Health Unit, Coimbra, Portugal Hugo Oliveira, Department of Dermatology and Venereology, Coimbra Local Health Unit, Coimbra, Portugal

Osteomalacia is a disorder of mineralization of newly formed osteoid that can be precipitated through mechanisms that result in hypocalcemia, such as prolonged vitamin D deficiency. Treatment is mainly focused on vitamin D supplementation; however, it can be largely ineffective in malabsorption syndromes. Targeted phototherapy is the localized delivery of ultraviolet light largely used in Dermatology to treat several skin diseases. It is also known that ultraviolet B radiation increases serum 25-hydroxyvitamin D levels. Although its role in the treatment of vitamin D deficiency is largely based on clinical experience,it should be considered, particularly in refractory cases. We report a 60-year-old female with osteomalacia secondary tovitamin D deficiency due to malabsorption after gastric bypass surgery. High dose supplementation of vitamin D and calciumwas largely ineffective. Narrowband ultraviolet B was initiated resulting in marked clinical response and normalization of25-hydroxyvitamin D serum levels.

Keywords: Phototherapy. Narrowband ultraviolet B phototherapy. Osteomalacia. Vitamin D deficiency.