Background: Vitamin D deficiency plays a role in autoimmune diseases and risk of fractures. No data are available on vitamin D levels and vertebral fractures in autoimmune bullous skin diseases.
Objectives: To assess serum vitamin D levels and the prevalence of vertebral fractures in patients with pemphigus vulgaris (PV) and bullous pemphigoid (BP), potentially fatal autoimmune bullous disorders.
Methods: We studied 13 consecutive inpatients with untreated active PV (six men and seven women, mean ± SD age 53·5 ± 14·3 years), 15 with BP (seven men and eight women, mean ± SD age 76·9 ± 12·4 years) and 28 age-, body mass index- and sex-matched controls. The 25-hydroxyvitamin D (25-OHD) levels and presence of vertebral fractures on spinal X-ray were assessed in all subjects.
Results: In patients with PV, 25-OHD levels were lower (mean ± SD 12 ± 4·4 ng mL(-1) ) and prevalence of severe hypovitaminosis D higher (62%) than in controls (mean ± SD 22·2 ± 11·7 ng mL(-1) , P = 0·012; 23%, P = 0·0047, respectively). The prevalence of fractures was 54% and 31% in patients with PV and controls, respectively. Patients with BP showed lower 25-OHD levels (mean ± SD 9·6 ± 7·2 ng mL(-1) ) and higher prevalence of severe hypovitaminosis D (73%) than controls (mean ± SD 22·6 ± 18·7 ng mL(-1) , P = 0·022; 27%, P = 0·01, respectively). The prevalence of fractures tended to be higher in patients with BP than in controls (67% vs. 33%, respectively, P = 0·068).
Conclusions: The low 25-OHD levels found in PV and BP may suggest a role for this agent in their pathogenesis. The increased prevalence of fractures should be taken into consideration in patients who must be given corticosteroids.
© 2012 The Authors. BJD © 2012 British Association of Dermatologists.