2025 – PAGE 82 – ENDOCRINOLOGY

CUSHING SYNDROME (AKA CUSHING’S SYNDROME)

CUSHING SYNDROME = HYPERCORTISOLISM = POOR growth/slow growth rate, striae, obesity, moon face, buffalo hump and muscle weakness. CUSHING DISEASE = Hypercortisolism due to a CENTRAL cause

PEARL: If the patient is tall, it’s NOT Cushing syndrome. If the patient is tall, is obese, and has stretch marks, consider high caloric intake.

ADDISON DISEASE (AKA ADDISON’S DISEASE)

ADDISON DISEASE (AKA ADDISON’S) = ADRENAL INSUFFICIENCY = Electrolyte shifts (hyperkalemia or hyponatremia) can result in weakness, myalgias, malaise, nausea, and vomiting. HypOglycemia occurs from a lack of cortisol. ACTH levels are HIGH and can result in hyperpigmentation. When an ACTH stimulation test (Cosyntropin) is performed, a normal response (a rise in cortisol levels) does not occur. Patients may have elevated levels of ADH. This is an appropriate elevation and should NOT be diagnosed as SIADH.

• ­MNEMONICS and PEARLS:
  • Keeping track of which eponym refers to cortisol deficiency or excess can be tough. Instead of ADrenal Insufficiency, call it “ADrenal D” So ADdison’s Disease = “ADrenal Deficiency” = AD D and AD D = ADDison’s!!!
  • It also means Aldosterone D Aldosterone helps with sodium retention and potassium excretion. In “AD D,” it is deficient, resulting in hyperkalemia and hyponatremia. If you ever see this combination of electrolytes on a chemistry panel, have a HIGH suspicion for some type of aldosterone deficiency.
  • If they talk about a patient having a really good “tan,” they may be referring to Addison’s-related hyperpigmentation.
  • “Think of the rise in ADH levels as an appropriate effort to retain water due to insufficient mineralo­corticoid (aldosterone)!”
• ­PRIMARY ADDISON’S DISEASE is the most common reason for adrenal insufficiency in children. It results in slow autoimmune destruction of the adrenal gland.
• ­ADRENAL INSUFFICIENCY can also be due to infection, adrenal hemorrhage (which results in very abrupt signs of Adrenal Insufficiency), or can be idiopathic.
• ­SECONDARY ADRENAL INSUFFICIENCY = A pituitary issue = LOW There is NO hyperkalemia or hyponatremia. ACTH stimulationwith Cosyntropin does result in improved cortisol levels. Patients sometimes have other midline defects.
  • PEARL: Sodium and potassium levels are okay in secondary adrenal insufficiency because the Renin-Angiotensin (R-A) System is fine (since the adrenal glands are NORMAL and aldosterone is being produced).
  • MNEMONIC: Secondary adrenal insufficiency is sometimes associated with midline defects. “This makes sense since the pituitary is also a midline structure!”
• ­TREATMENT
  • Maintenance therapy for Primary Adrenal Insufficiency is Hydrocortisone (to replace cortisol) and Fludrocortisone (to replace aldosterone).
  • Maintenance therapy for Secondary Adrenal Insufficiency is just hydrocortisone (to replace cortisol). Since the R-A System is intact, fludrocortisone is not needed.
  • Give stress dose steroids for fever, acute illness, surgery, or trauma. A mild illness (like a URI without fever) does not require stress dose steroids. The stress dose is usually double, or triple, the maintenance dose.
  • SALINE + GLUCOSE + IV HYDROCORTISONE for ADRENAL CRISIS. Signs, symptoms, and labs in an adrenal crisiscan include nausea, vomiting, malaise, hyperkalemia, and hyponatremia.