Volume 180 - Issue 10
Diagnosis and management of hyperthyroidism and hypothyroidism
Author: Malvinder S Parmar
Med J Aust 2004; 180 (10): 541-542. || doi: 10.5694/j.1326-5377.2004.tb06066.x
Published online: 17 May 2004
Published online: 17 May 2004
Malvinder S Parmar
Medical Director (Internal Medicine), Timmins and District Hospital, Suite 108, 707 Ross Ave East, Timmins, ON P4N 8R1, Canada. atbeatATntl.sympatico.ca
To the Editor: I wish to add another cause of exogenous hyperthyroidism to those mentioned in the comprehensive review on hyper- and hypothyroidism by Topliss and Eastman.1 Inadvertent ingestion of animal thyroid (“hamburger” thyrotoxicosis), although rare, is worth mentioning. Meat may be inadvertently contaminated with thyroid tissue through the process of “gullet trimming” during butchering. While this process has been prohibited in most countries since the recognition of outbreaks of hamburger thyrotoxicosis,2,3 it may still occur when farm animals or wild game are prepared for consumption by farmers, hunters or local butchers unaware of the prohibition.
I recently reported a case of a woman living on a farm in Canada who had five episodes of transient hyperthyroidism over a decade.4 These were initially diagnosed as episodes of “silent thyroiditis”, but were later attributed to consumption of meat patties contaminated with thyroid tissue, as the local butcher was not aware of the prohibition on gullet trimming. A history of eating wild game or locally prepared meat should be considered before a diagnosis of silent thyroiditis is made. Thyroid uptake of radioiodine is low in both conditions, but serum thyroglobulin level is raised in thyroiditis and decreased during the hyperthyroid phase of exogenous hyperthyroidism.
References
- Topliss DJ, Eastman CJ. Diagnosis and management of hyperthyroidism and hypothyroidism. Med J Aust 2004; 180: 186-193. CHDHFDGC
- Hedberg CW, Fishbein DB, Janssen RS, et al. An outbreak of thyrotoxicosis caused by the consumption of bovine thyroid in ground beef. N Engl J Med 1987; 316: 993-998.
- Kinney JS, Hurwitz ES, Fishbein DB, et al. Community outbreak of thyrotoxicosis: epidemiology, immunogenetic characteristics, and long-term outcome. Am J Med 1998; 84: 10-18. i1083049
- Parmar MS, Sturge C. Recurrent hamburger thyrotoxicosis. CMAJ 2003; 169: 415-417. CHDDJFDG