Reactions 1364 - 13 Aug 2011

Carbamazepine

Biotin deficiency in a child: case reportA 5-year-old girl developed biotin deficiency following

treatment with carbamazepine.The girl was diagnosed with glycogen storage disease

(GSD) type Ib at the age of 2 months, and subsequentlyrequired dietary therapy with GSD formula. She had thinhair throughout infancy. At 3 years of age, she washospitalised after experiencing a severe hypoglycaemicepisode and status epilepticus. She recovered after 1 weekand commenced prophylactic antiepileptic therapy withcarbamazepine [route and dosage not stated].Carbamazepine was withdrawn 1 month later due to asuspected drug eruption. Despite topical therapy, her skineruption failed to improve. Five months later, biotindeficiency was suspected. Laboratory findings included aserum free biotin level below the detectable level, a lowserum carnitine level, an elevated C5-OH level and anincreased C3/C2 ratio. Urinalysis revealed elevated3-methylcrotonylglycine, methylcitric acid and3-hydroxyisovaleric acid levels. She was diagnosed withbiotin deficiency.

Treatment included supplementation with biotin andlevocarnitine. Within 2 weeks, the girl’s dermatitis and hairthickness had improved. Her skin lesions had resolved after3 months of biotin supplementation, and her hair growthand blood acylcarnitine levels had also normalised.

Author comment: "[W]e hypothesize that startingcarbamazepine administration may have led to decreasedbiotin production."Ihara K, et al. Biotin deficiency in a glycogen storage disease type 1b girl fed onlywith glycogen storage disease-related formula. Pediatric Dermatology 28: 339-341,No. 3, May-Jun 2011. Available from: URL: http://dx.doi.org/10.1111/j.1525-1470.2011.01238.x - Japan 803058614

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Reactions 13 Aug 2011 No. 13640114-9954/10/1364-0001/$14.95 © 2010 Adis Data Information BV. All rights reserved