Thyroid Storm at Sea: A Case Report of Algae‐Induced Thyrotoxicosis

Iodine‐induced thyrotoxicosis (IIT), also known as the Jod‐Basedow phenomenon, is a rare yet recognized cause of hyperthyroidism. While iodinated contrast is the most frequent trigger, iodine‐rich supplements such as seaweed products or supplements can also precipitate thyrotoxicosis, particularly in individuals with prior chronic iodine deficiency or preexisting thyroid nodular disease. We present a case of thyroid storm following short‐term ingestion of Irish sea moss as part of a “crash diet.” A 37‐year‐old woman with type 1 diabetes mellitus, well controlled on subcutaneous insulin therapy, presented with nausea and vomiting after 6 days of following a restrictive diet consisting solely of fruit juices and sea moss supplements. Physical examination revealed tachycardia and tremors. Laboratory workup confirmed thyroid storm with a suppressed thyroid‐stimulating hormone (TSH) <0.01 mU/L, markedly elevated free T4, and concurrent diabetic ketoacidosis (DKA). Notably, thyroid labs performed 2 years prior had been abnormal; however, she did not seek follow‐up. She was admitted to the intensive care unit for treatment with intravenous beta‐blockade (metoprolol), propylthiouracil (PTU), corticosteroids, and potassium iodide every 6 h. Insulin infusion was initiated for DKA. Due to worsening transaminitis, PTU was replaced with methimazole and cholestyramine. She stabilized and transitioned to oral medications. However, she left against medical advice on hospital day 6 and was lost to follow‐up. This case underscores the potential for rapid‐onset, severe thyrotoxicosis following short‐term ingestion of iodine‐rich supplements in predisposed individuals. While seaweed‐induced IIT is documented, this case demonstrates that even brief exposure can trigger life‐threatening thyroid storm. The unregulated nature of such supplements poses a growing public health risk. Clinicians should maintain a high degree of suspicion for dietary supplement‐induced thyroid dysfunction and educate patients, especially those with known or suspected thyroid abnormalities, on the risks of iodine‐containing products such as Irish sea moss.