Thyroid storm or thyrotoxic crisis is a rare but severe and potentially life-threatening complication of hyperthyroidism (overactivity of the thyroid gland). It is characterized by a high fever (often above 40°C/104°F), fast and often irregular heart beat, vomiting, diarrhea and agitation. Heart failure may occur, and myocardial infarction is encountered. Death may occur despite treatment. Most episodes occur either in those with known hyperthyroidism whose treatment has been stopped or become ineffective, or in those with untreated mild hyperthyroidism who have developed an intercurrent illness (such as an infection).
The severity of hyperthyroidism, thyrotoxicosis and thyroid storm can be assessed with the Burch-Wartofsky score, first introduced in 1993. A score is derived from various clinical parameters (such as temperature, severity of agitation); a score below 25 excludes thyroid storm, 25–45 suggests impending storm, and above 45 is suggestive of thyroid storm.
Thyroid storm requires prompt treatment and hospitalization. Often, admission to the intensive care unit is needed. Inorganic iodide (e.g. Lugol's iodine) and antithyroid drugs (methimazole or propylthiouracil) are used to reduce the release of thyroid hormone from the gland, and beta blockers to reduce the effect of circulating thyroid hormone on end organs. In high fever, temperature control is achieved with paracetamol/acetaminophen, and frequently fluid replacement, mechanical ventilation and corticosteroids. Any suspected underlying cause is also addressed.
- Klubo-Gwiezdzinska, Joanna; Wartofsky, Leonard (March 2012). "Thyroid emergencies". Medical Clinics of North America 96 (2): 385–403. doi:10.1016/j.mcna.2012.01.015. PMID 22443982.
- Burch, HB; Wartofsky, L (June 1993). "Life-threatening thyrotoxicosis. Thyroid storm.". Endocrinology and metabolism clinics of North America 22 (2): 263–77. PMID 8325286.
- Bahn, RS; Burch, HB; Cooper, DS; Garber, JR; Greenlee, MC; Klein, I; Laurberg, P; McDougall, IR; Montori, VM; Rivkees, SA; Ross, DS; Sosa, JA; Stan, MN; American Thyroid, Association; American Association of Clinical, Endocrinologists (June 2011). "Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists.". Thyroid : official journal of the American Thyroid Association 21 (6): 593–646. PMID 21510801.