Endocrine Abstracts

Introduction: Isolated vomiting is a rare often forgotten presentation of Graves’s disease and can lead to delayed diagnosis. Multiple case reports quote vomiting in thyrotoxicosis co-presenting with Addisonian crisis, diabetic ketoacidosis or with abnormal liver function and jaundice. Another common association is hyperemesis gravidarum. Vomiting in paraneoplastic hyperthyroidism occurs through a similar mechanism of beta-HCG secretion, mainly related to germ-line tumours. We present a case of severe prolonged vomiting caused by Graves’s disease.

Case presentation: A 46 years old postmenopausal woman of Afrocaribbean origin presented with unremitting vomiting and dramatic 38 kg weight loss over 3 months. She reported tiredness, headaches and anxiety. Her heart rate was 91/min sinus rhythm, BP 115/80, temperature 37.2°C. She had no palpable thyroid nor thyroid eye signs. Thyroid function tests showed suppressed TSH<0.01 mU/l and elevated fT4 86.9 pmol/l.

Further investigations and progress: Thyroid uptake scan and TSH-receptor antibodies confirmed Graves’s disease. Her liver function tests were normal. Gastroscopy and CT body imaging were normal. Beta-HCG was negative. The patient required a prolonged two weeks admission for managing her unremitting vomiting during which Propylthiouracil and Propranolol were administered via nasogastric tube. Vomiting was refractory to antiemetics but improved alongside amelioration of hyperthyroidism with antithyroid medication. There was no further recurrence at follow up.

Conclusion: The pathophysiology of thyrotoxicosis-associated vomiting is related to the thyrotoxic adrenergic effect on peristalsis, while high oestrogen levels in hyperthyroidism in both sexes have also been quoted. Previous case reports have no Graves’s thyroid eye signs making early diagnosis challenging. Typically such vomiting fails to respond to usual antiemetics, but responds to antithyroid medications. Glucocorticoids are also useful adjuncts in bringing symptoms under control.

Recommendations: Increased awareness of vomiting as presentation of thyrotoxicosis is necessary in order to avoid a delayed diagnosis. Ruling out alternative aetiologies is also important. Rare paraneoplastic thyrotoxic conditions may present as such.