Aplasia cutis congenita with skull defect in a monozygotic twin after exposure to methimazole in utero.
BACKGROUND
Aplasia cutis congenita (ACC) is a condition in which localized or widespread areas of skin are absent at birth. Defective lesions show complete absence of all layers of skin, occasionally extending to skull or dura. ACC is etiologically heterogeneous; many different etiologies including teratogens have been documented.


METHODS
We describe the first reported case of a monozygotic twin with ACC after exposure to methimazole in utero. The female patient was born at 36 weeks gestation as the first child of monozygotic twins. The mother received methimazole between the 11th and 17th weeks of pregnancy because of transient hyperthyroidism. The second child did not have ACC. The patient had defects of the scalp, skull, and dura (7 x 5 cm) on the sagittal line of the parieto-occipital region. No other malformations were noted. The scalp defect has been treated daily with sterile physiological saline and petrolatum dressing in addition to intravenous antibiotics. Trafermin, a recombinant human fibroblast growth factor, was sprayed from day 6 to promote epithelialization of the scalp defect. On day 21, she had high fever due to infection of the defect lesion, which was controlled by povidone iodine dressing and intravenous antibiotics. The defect of the scalp was well healed after 6 weeks, but the skull defect remained unclosed.


CONCLUSIONS
We describe a rare case of a monozygotic twin with ACC and skull defect after methimazole exposure in utero. The findings of our case suggest that methimazole is a potential teratogen of ACC.
Iwayama
Hideyuki
H
Department of Pediatrics, Ogaki Municipal Hospital, Ogaki, Gifu, Japan. iwahide@yello.livedoor.com
Hosono
Haruki
H
Yamamoto
Hikaru
H
Oshiro
Makoto
M
Ueda
Norishi
N
D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D013956:Antithyroid Agents / Q000008:administration & dosage / Q000009:adverse effects*; D004476:Ectodermal Dysplasia / Q000139:chemically induced* / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy; D007231:Infant, Newborn; D007239:Infections / Q000188:drug therapy; D008297:Male; D008713:Methimazole / Q000008:administration & dosage / Q000009:adverse effects*; D010446:Peptide Fragments / Q000494:pharmacology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy; D011261:Pregnancy Trimester, First; D012886:Skull / Q000002:abnormalities*; D014430:Twins, Monozygotic