Primary adrenal insufficiency (Addison's disease)

Clinical Features

decreased cortisol, adrenal sex hormone, and aldosterone secretion

S/S - weakness, paresthesias, cramping, N, V, D, intolerance to stress, and personality changes  (irritability and restlessness), 'salt-craving'

• 99% weakness
• 97% weight loss
• 34% Abdominal pain
• 20% Anorexia progressing to nausea and vomiting
• 19% Constipation

Chronic cases -  small heart, weight loss

• hyperpigmentation of the skin - diffuse brown, tan, or bronze darkening (especially palmar creases) due to increased pituitary secretion of ACTH and melanocyte-stimulating hormone (MSH)
  • ACTH is derived from a larger precursor molecule called proopiomelanocortin (POMC). When POMC is cleaved to produce ACTH, other melanocyte-stimulating hormones (MSH) are also produced. These MSHs have the effect of stimulating melanocytes in the skin to produce more melanin, the pigment responsible for skin colour
  • primary Addison's is associated with hyperpigmentation whereas secondary adrenal insufficiency is not
• vitiligo
• sparse axillary hair; loss of pubic hair in women
• (arterial) hypotension - orthostatic (secondary to lack of vascular effect of cortisol on vascular tone)
• hypoglycaemia
• hyponatraemia and hyperkalaemia may be seen
• crisis: collapse, shock, pyrexia

Up to half of the patients with autoimmune adrenalitis have other autoimmune disorders, which may also flare up in the postpartum period.

N.B. Tuberculosis (TB) is a common cause of chronic Addison's disease in endemic areas. (most common cause worldwide)