Hashimoto's Thyroiditis
What antibody titer is positive in Hashimoto's thyroiditis?
anti-TPO (antimicrosomal)
Which pituitary hormones does Sheehan syndrome affect?
decreases GH, prolactin, FSH/LH, ACTH, TSH production
What is the MCC Addison's disease in developing countries?
Tuberculosis (infectious adrenalitis)
A 35-year-old woman presents with a painful, tender thyroid and recent upper respiratory infection. Her labs show elevated ESR, hypocholesterolemia, low TSH, and high free T4. What is her most likely Dx?
De Quervain's thyroiditis (subacute granulomatous thyroiditis)
How does a thyroid typically present in Hashimoto's thyroiditis?
Moderately enlarged, non-tender, rubbery thyroid
What is Sheehan syndrome a complication of?
Postpartum hemorrhage
What is the MCC Waterhouse-Friderichson syndrome?
bacterial sepsis from Neisseira meningitidis
A 28-year-old woman is six months postpartum and presents with fatigue, cold intolerance, and wgt gain. Her thyroid is not enlarged. Her BMP is normal. Endocrine labs are pending. What is her most likely Dx based on the current information?
Postpartum thyroiditis
Why does Hashitoxocisos occur?
Transient hyperthyroidism due to release of pre-formed T3/T4 when CD8+ T cells and autoantibodies attack follicular cells
Why are pregnant women at risk of Sheehan syndrome?
Hyperplasia of lactotrophs in preparation for breast feeding increases nutrient demand, making anterior pituitary at risk for ischemia
Which hormones is pro-opiomelanocortin (POMC) a precursor to?
ACTH (stress response), α-MSH (appetite regulation), β-MSH (skin pigmentation), and β-endorphin (natural opioid for relieving and mood)
A 25-year-old woman presents with chronic fatigue, wgt loss, hyperpigmentation, and hypotension. She reports difficulty getting pregnant for the past year. Her BMP shows hyponatremia, hypoglycemia, and hyperkalemia What labs should you order to confirm your suspected Dx?
ACTH stimulation test: no/low cortisol response
Titers: (+) anti-21-hydroxylase
Besides low FT4, elevated TSH, and (+) titers, name 2 other abnormal lab/diagnotstic findings in Hashimoto's thyroiditis.
Labs: Hypercholesterolemia, Hyperprolactinemia
MRI: Pituitary mass
Thyroid Bx: Hurthle cells, lymphoid aggregates with germinal center
What results do you expect on a BMP from a patient with Sheehan syndrome?
Hyponatremia, Hypoglycemia
Bonus: pancytopenia on CBC
When would you give hydrocortisone over prednisone to treat adrenal insufficiency?
Hydrocortisone: children, pregnant pts (does not cross placenta), adrenal crisis
Prednisone: chronic glucocorticoid replacement
A 28 year-old postpartum woman with a known pituitary macroadenoma presents with sudden-onset severe headache, visual disturbances, and N/V. What can you find on a head MRI to confirm your suspected Dx?
Sellar hemorrhage
What 2 HLA types are associated with Hashimoto's thyroiditis?
HLA-DR3 and HLA-DR5
How can you differentiate Sheehan syndrome from a pituitary apoplexy?
SS is a complication of postpartum hemorrhage. PA is a typically occurs with a pituitary adenoma.
In an MRI, SS will show empty/partial sella turcica from pituitary atrophy. PA will show pituitary hemorrhage.
Also, PA mainly affects ACTH and GH, so it will probably NOT present with sxs related to decreased prolactin, FSH, LH, TRH.
What physical exam and labs findings would you expect in primary adrenal insufficiency, but will not see in secondary/tertiary adrenal insufficiency?
hyperkalemia (aldosterone synthesis preserved in fcnl adrenal gland), hyperpigmentation (no POMC to make ACTH or MSH)
A previously healthy 5-year-old boy presents with sudden onset fever, purpuric rash, hypotension, and AMS. Blood cultures are (+) with gram (-) diplococci. His labs show hyperkalemia, hyponatremia, and hypoglycemia. What treatments should you start right away?
IV empiric antibiotics (ceftriaxone +/-vancomycin), IV Hydrocortisone, Supportive care (IV fluids, electrolyte correction, etc.)