Addison's disease Flashcards
Addison’s disease
What is it?
Primary adrenal insufficiency
Addison’s
What hormones are deficient?
Name the 3 adrenocortical hormones
adrenocortical hormones
- cortisol
- aldosterone
- dehydroepiandrosterone
Addison’s
What are some common associated symptoms?
- Fatigue
- Anorexia
- Weight loss
- Nausea
- Vomiting
Addison’s
What are some common associated signs?
- Hyperpigmentation – present in mucosa and sun-exposed areas, more pronounced in palmer creases, areas of friction and scars
- Hypotension – systolic <110 mmHg
- Women may have loss of axillary and pubic hair
Addison’s
What are some common associated risk factors?
- Female sex – over 90% of patients with Addison’s disease are female
- Adrenocortical autoantibodies – if a patient tests positive for adrenocortical autoantibodies, their risk of developing Addison’s disease is approximately 50%
- Adrenal haemorrhage – use of anticoagulants or being in a thromboembolic and hypercoagulable state (e.g. antiphospholipid syndrome and sepsis)
Addison’s
What are the first line investigations?
- serum electrolytes
- blood urea
- FBC
- morning serum cortisol (8am-9am)
Addison’s
What might be found on these investigations?
- serum electrolytes
- blood urea
- FBC
- serum electrolytes (not for diagnosis, but hyponaetremia/hyperkalaemia are common)
- blood urea (elevated is an indicator)
- FBC (anaemia, eosinophilia)
Addison’s
What time should we so the morning serum cortisol test?
What do we use it for?
How do we interpret the results?
8-9am
used as a test of exclusion
- Levels <83 nanomols/L are highly suggestive of adrenal insufficiency
- Levels >497 nanomols/L effectively exclude Addison’s disease
- Levels between 83-497 nanomols/L require further investigation with a high-dose adrenocorticotrophic hormone (ACTH) stimulation test to confirm a diagnosis
Addison’s
What are some 2nd line investigations?
- ACTH stimulation test
- Serum ACTH levels
- Plasma aldosterone
- Adrenal imaging
Addison’s
What would it be indicated to do a ACTH stimulation test?
How do we interpret the results?
used if morning serum cortisol levels are between 83-497 nanomols/L
- If cortisol levels are <497 nanolmols/L are found at either 30 or 60 minutes after ACTH stimulation, the diagnosis of adrenal insufficiency is highly likely
- Cortisol levels >497 at 30 or 60 minutes after administration of ACTH excludes the diagnosis of primary adrenal insufficiency in most cases
Addison’s
What would it be indicated to do a serum ACTH level test?
How do we interpret the results?
used if ACTH stimulation tests are consistent with adrenal insufficiency (<497 nanomols/L)
- A high level would be suggestive of primary adrenal insufficiency
- A low value would support a secondary adrenal insufficiency
Addison’s
What would it be indicated to do a plasma aldosterone test?
How do we interpret the results?
required if serum ACTH levels are inconclusive
- Low plasma aldosterone levels are supportive of Addison’s disease
Addison’s
What would it be indicated to do adrenal imaging?
CT or MRI may be required in patients diagnosed with primary adrenal insufficiency where the underlying cause is still uncertain
Addison’s
What might cause an addisonian crisis?
- pts with addisons that are in a situation that required increased steroids (trauma, infections, surgery), but they are not given
- non-addisons pts on long term steroid treatment who have forgotten/are unable to take their tablets
basically, too little steroids being taken
Addison’s
How would an addisonian crisis be diagnosed?
- shock presentation (tachycardia, vasoconstriction, postural hypotension, oliguria, weak, confused, comatose)
- suggestive PMH of addisons or long term steroid treatment
