Addison’s disease

Addison’s disease

Primary Hypoadrenalism

Pathology:                    Glucocorticoidand mineralocorticoid deficiency due to failure of adrenal glands.


Aetiology:                    Autoimmune - 90% of cases

Infections - TB, HIV

Congenital - Congenital Adrenal Hyperplasia

Malignancy – Lymphoma, metastasis

Infiltration - Amyloidosis or sarcoidosis

Vascular – Haemorrhage, infarction, anticoagulants,meningococcal sepsis

       (Waterhouse-Friderichsen Syndrome), antiphospholipidsyndrome.

Iatrogenic – Adrenalectomy

Drugs – Ketoconazole, busulfan, methadone



Symptoms:                   Fatigue, weight loss, nausea,poor appetite, dizziness

                                         Addisonian Crisis: Fever, vomiting, abdominal pain, hypotension,tachycardia,

          collapse, coma andhypovolaemic shock

Signs:                              Hyperpigmentation,postural hypotension, muscle wasting, vitiligo


Investigations:          Bloods:Hyponatraemia, hyperkalaemia, hypoglycaemia, TFTs, Coeliac screen,

serum cortisol (low), serum ACTH (raised), short synacthentest

Imaging: Chest X-ray,CT adrenals, bone density scan to monitor osteoporosis


Treatment:                  Hydrocortisone 10-20mg/day individed doses – should be doubled when ill

Fludrocortisone 0.05-0.2 mg/day

Addisonian Crisis Treatment (5S’s)- Salt (saline), Sugar (Dextrose), Steroids,

       Support, Search forprecipitating cause

Complications:          Adrenal crisis at presentation/intercurrentillness, steroid over-replacement, other autoimmune conditions


Prognosis:                    Life expectancy reduced by10-20 years. Steroid over-replacement leads to increased morbidity



Synacthen Test

Underlying Pathology



Cortisol ↑

Cortisol ↑

No abnormalities.

Synacthen is an ACTH analogue so will  increase normal Cortisol production

No change

Cortisol ↑

Secondary Hypoadrenalism

No change

No change

Primary Hypoadrenalism (Addison’s Disease)


Figure 5.6  SynacthenTest Results. Short and Long test can help differentiate between Primary

(Addison’s) or Secondary Hypoadrenalism



Secondary Hypoadrenalism


Pathology:                    ACTHdeficiency as part of hypopituitarism


Aetiology:                    Iatrogenic – Long term steroid therapyleading to hypothalamic-pituitary-

           adrenal suppression

ACTH Disorder: Any pituitary or hypothalamicdisorder which causes a

      reduction in ACTH


Symptoms:                   Fatigue, weight loss, nausea,poor appetite, dizziness          


Signs:                              Posturalhypotension, muscle wasting, vitiligo


Investigations:          Bloods:Hypoglycaemia, TFTs, serum cortisol (low), serum ACTH (low), short

  and long synacthentest


Treatment:                  Hydrocortisone 10-20mg/day individed doses


Complications:          Steroid over-replacement


Prognosis:                    If due to steroid overreplacement, then adrenal glands will recover following steroid withdrawal

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