Cushing syndrome is the set of signs caused by long exposure to too much cortisol. The most common cause is steroid medicine such as prednisone; other causes are a pituitary tumor, an adrenal tumor or a tumor elsewhere that makes ACTH.
Key symptoms
- Weight gain, mostly in the face and trunk
- Thin skin, easy bruising and slow wound healing
- Weak muscles and tiredness
- Low mood, anxiety or poor sleep
- Irregular periods, low libido and extra facial hair
What you find on exam
- Moon face, buffalo hump and thin arms and legs
- Wide purple striae over 1 cm
- High blood pressure and swelling
- Proximal muscle weakness
- Acne, bruises and signs of infection
Tests
- Ask about all steroid use: pills, inhalers, creams and injections
- Two screening tests: 1 mg dexamethasone suppression, late-night salivary cortisol or 24-hour urine cortisol
- ACTH level: low means an adrenal cause, normal or high means ACTH-driven
- Imaging guided by ACTH: adrenal CT or pituitary MRI; glucose, HbA1c and potassium
Treatment basics
- Steroid medicines: taper slowly to the lowest dose and never stop suddenly
- Surgery to remove the tumor: pituitary, adrenal or ectopic source
- Cortisol-lowering drugs such as ketoconazole, metyrapone or osilodrostat when surgery is not possible
- Treat diabetes, high blood pressure and bone loss; vaccinate and prevent clots
Red flags
- Very low potassium with high blood pressure (suggests ectopic ACTH)
- Fast onset with severe weakness or psychosis
- Fever or infection in a patient with cortisol excess
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.