title: Aplasia cutis congenita in surviving co-twin after propylthiouracil exposure in utero.
abstract: OBJECTIVE
  Aplasia cutis congenita (ACC) has been observed after fetal exposure to the antithyroid drug methimazole (MMI), but not reported after propylthiouracil (PTU), the current antithyroid drug of choice during pregnancy. This occurrence has implications for patient information and causal research.
  
  
  METHODS
  We describe a surviving term co-twin to a mother with hyperthyroidism exposed to PTU from conception to 34 weeks of gestation presenting with ACC at birth.
  
  
  CONCLUSIONS
  The association between PTU exposure and ACC is clinically relevant and allows speculation on the etiology. A similar mechanism to the classical MMI-induced ACC is postulated, unless a vascular etiology suggested by a vanishing twin or maternal hyperthyroidism itself is causal. Coincidence of PTU exposure and ACC seems unlikely.
  
  
  CONCLUSIONS
  ACC in a newborn after PTU exposure during pregnancy hitherto observed only after MMI strongly encourages further reports of similar cases that may remain clinically underdiagnosed or unreported. Such confirmation could have significant implications for maternal treatment of hyperthyroidism, common in women of childbearing age.
authors.affiliation: Department of Neonatology, University Hospital of Geneva, 1211 Geneva, Switzerland.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Löllgen
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Calza
authors.forename: Valérie M
authors.initials: VM
authors.lastname: Schwitzgebel
authors.forename: Riccardo E
authors.initials: RE
authors.lastname: Pfister
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology / Q000473:pathology; D013956:Antithyroid Agents / Q000009:adverse effects*; D004200:Diseases in Twins / Q000209:etiology / Q000473:pathology; D004476:Ectodermal Dysplasia / Q000209:etiology / Q000473:pathology*; D005260:Female; D005865:Gestational Age; D006111:Graves Disease / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D007231:Infant, Newborn; D018811:Maternal Exposure; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000188:drug therapy; D011441:Propylthiouracil / Q000009:adverse effects*
chemical_list: D013956:Antithyroid Agents; D011441:Propylthiouracil