6594 A Rare Case of Clomiphene Induced De Quervain’s Subacute Thyroiditis

Abstract Disclosure: A. Abdelhameed: None. M. Mortagy: None. A. Elsandouby: None. A. Ghaffar: None. Introduction: Clomiphene is a selective estrogen receptor modulator that stimulates LH release by inhibiting negative feedback on the hypothalamic-pituitary axis. De Quervain’s subacute granulomatous thyroiditis is usually caused by viral infections and less often is drug-induced. We present a case of possible subacute thyroiditis induced by clomiphene. To the best of ourknowledge, this association has not been reported before. Case presentation: A 35-year-old female with a past medical history of unexplained infertility presents to the general medicine clinic with severe neck pain for the last 5 days. Her neck pain started 2 days after the completion of the clomiphene course for induction of ovulation (50 mg daily for 5 days). She denied upper respiratory symptoms. She had an extremely tender thyroid with no palpable nodules. Throat was clear. She was clinically euthyroid with no rash or itching. TSH was 3.9 mIU/L (TSH was normal 6 months prior). ESR was 40 mm/hr. Thyroid ultrasound was unremarkable. She was treated with Ibuprofen for subacute thyroiditis. In the first 2 weeks, the patient complained of increased anxiety. In the next month, she had a missed menstrual cycle. Her pain and tenderness resolved after 50 days. Repeat TSH was 2.4 mIU/L. The patient was advised not to retake clomiphene. Discussion: This is a typical presentation of subacute thyroiditis as persistent thyroid pain and tenderness with elevated ESR. The patient didn’t have the classical symptoms of preceding viral infection. However, her symptoms began immediately after completion of clomiphene course suggesting a temporal relation. The patient didn’t have any history of thyroid problems. She had increased anxiety initially followed by a missed period which suggests clinical thyroid dysfunction.Clomiphene has been associated in the literature with an increased risk of thyroid cancer. Uncontrolled thyroid dysfunction is a contraindication for clomiphene use. This might suggest an interaction between clomiphene and thyroid homeostasis. Subacute thyroiditis could be caused by drugs (e.g., lithium and amiodarone). This suggests that other drugs could lead to subacute thyroiditis such as clomiphene in our case. Conclusion: Clinicians should be aware that clomiphene could be associated with thyroid disorders such as subacute thyroiditis. It is also important to note that thyroid dysfunction is a contraindication for clomiphene use. Presentation: 6/3/2024