Celiac disease presenting as resistant hypothyroidism.

The high prevalence of celiac disease in patients with autoimmune hypothyroidism, compared to the general population, has been well documented but screening for celiac disease is not recommended as yet in otherwise asymptomatic hypothyroid patients. In recent years the high prevalence of undiagnosed celiac disease in the general population, largely as a result of the many atypical manifestations of the disease, has become apparent. We report the case of a 58-year-old woman with autoimmune hypothyroidism who was initially suspected of having celiac disease on the basis of apparent resistance to levothyroxine therapy, and who had no other clinical or laboratory clues to suggest the diagnosis. Cases of undiagnosed celiac disease causing levothyroxine malabsorbtion have previously been described, but all previous cases had other obvious manifestations of the disease. We believe that this atypical presentation of celiac disease warrants further attention, and that the diagnosis of celiac disease should always be considered in patients requiring higher than expected doses of thyroid hormone replacement, even in patients with normal bowel habit, and no other apparent manifestations of the disease.