Introduction

-Primary adrenocortical insufficiency (Addison disease) is a syndrome resulting from the chronic deficiency of cortisol caused by adrenocortical insufficiency 

-Secondary adrenocortical insufficiency is due to ACTH deficiency, caused by exogenous glucocorticoid therapy, pituitary or hypothalamic tumors 

-in primary adrenal insufficiency, low or absent cortisol level results in hypersecretion of ACTH by the pituitary

-ACTH stimulates melanocyte activity, resulting in generalized hyperpigmentation, which is the most specific sign of primary adrenal insufficiency

-Addison’s disease occurs when >90% of adrenal tissue is destroyed

-The most common cause is autoimmune destruction 

Symptoms & Signs 

General: Weakness, malaise, anorexia, weight loss, craving for salt 

Vascular: postural hypotension

GI: Nausea, vomiting, diarrhea, constipation, abdominal pain

Musculoskeletal: Myalgia, arthralgia 

Metabolic: Hypoglycemia, hyponatremia,hyperkalemia 

Psychiatric: Personality changes 

Dermatological: Hyperpigmentation of the buccal mucosa and gums preceded by generalized hyperpigmentation of the skin, loss of axillary and pubic hair, vitiligo,calcification of auricular cartilage (petrified ears), longitudinal pigmented bands in the nails  

Gynecological: Amenorrhea, ovarian failure, infertility

Obstetrical: preterm delivery, low-birth weight newborn, increase in cesarean delivery

Emergency: Shock, coma, and death, if untreated

Diagnosis 

Labs: hyponatremia, hyperkalemia, acidosis, elevated serum creatinine and blood urea nitrogen, hypoglycemia, hypercalcemia

Hematology: Normochromic, normochromic anemia, neutropenia, eosinophilia, and lymphocytosis

Best screening test/Definitive diagnosis: Failure to respond adequately to corticotropin stimulation test

-MRI to rule out pituitary or hypothalamic tumor 

-CT scan of the adrenal glands

-Secondary Adrenal insufficiency: Diminished pigmentation, Normal serum potassium 

Treatment 

-Register with a medical alert system 

-Patient should be instructed in the self-administration of steroids

-Lifelong replacement therapy of glucocorticoids and mineralocorticoids 

-Medications: Hydrocortisone, prednisone, dexamethasone, fludrocortisone 

-Acute adrenocortical insufficiency: Medical emergency, parenteral hydrocortisone, correction of fluid and electrolytes 

Primary adrenal deficiency	Secondary adrenal deficiency
ACTH elevated	ACTH low or inappropriately normal
Aldosterone level can be low	Aldosterone level is normal
Hyperpigmentation	Diminished pigmentation
Elevated Potassium	Normal Potassium
Mineralocorticoid replacement needed	Mineralocorticoid replacement not needed