title: Iatrogenic osteomalacia: report of two cases.
abstract: CASE 1: An 80-year-old man presented at our hospital with pain in both knees.He had received continuous intravenous administration of saccharated ferric oxide (SFO) over a period of five years following a diagnosis of iron-deficiency anemia.Blood tests revealed hypophosphatemia (1.4 mg/dl) and high circulating levels of fibroblast growth factor 23 (FGF23) at 248.8 mg/dl.These findings led to the diagnosis of FGF23-related osteomalacia due to SFO administration.Accordingly, the treatment plan was first to discontinue SFO, which led to a decrease in pain and normalization of phosphorus and FGF23 after 1 month.CASE 2: A 63-year-old woman presented at our hospital with leg pain.She had undergone total gastrectomy for gastric cancer at 36 years of age.Blood tests revealed hypocalcemia (8.3 mg/dl) and hypophosphatemia (2.2 mg/dl), and 25(OH)D at no more than 5 pg/ml.Bone X-rays showed significantly diminished bone shadowing.These findings led to a diagnosis of vitamin D-deficient osteomalacia due to impaired absorption following total gastrectomy.For therapy, she was treated with 1 μg/day oral alfacalcidol.Two months after initiating treatment, the pain improved.
  
  
  CONCLUSIONS
  When a patient is diagnosed with unexplained pain, it is important to pay attention to the possibility of an iatrogenic etiology.
authors.affiliation: First Department of Internal Medicine, University of Occupational and Environmental Health, Japan.
authors.forename: Sunao
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Okada
authors.forename: Hiroko
authors.initials: H
authors.lastname: Mori
authors.forename: Akira
authors.initials: A
authors.lastname: Kurozumi
authors.forename: Keiichi
authors.initials: K
authors.lastname: Torimoto
authors.forename: Tadashi
authors.initials: T
authors.lastname: Arao
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000369:Aged, 80 and over; D018798:Anemia, Iron-Deficiency / Q000188:drug therapy; D005260:Female; D005290:Ferric Compounds / Q000009:adverse effects*; D000077605:Ferric Oxide, Saccharated; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D005743:Gastrectomy; D005937:Glucaric Acid / Q000009:adverse effects*; D006801:Humans; D007014:Hypophosphatasia / Q000150:complications; D007049:Iatrogenic Disease; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000139:chemically induced / Q000188:drug therapy / Q000209:etiology*; D011183:Postoperative Complications; D014808:Vitamin D Deficiency / Q000150:complications
chemical_list: C000717427:FGF23 protein, human; D005290:Ferric Compounds; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D000077605:Ferric Oxide, Saccharated; D005937:Glucaric Acid