Addison's Disease

There is essentially no increase in urinary cortisol metabolites after ACTH treatment, indicating that the adrenal gland is already operating at its maximal output (which, in this case, is very low). Addison's disease may occur through autoimmune destruction of the adrenal cortex ("idiopathic adrenalitis"), or may result from infection of the adrenal gland with tuberculosis or histoplasmosis. Both of these latter possibilities have been rare in recent years, but are now more common since AIDS and continuing developments in cancer chemotherapy and transplantation biology have increased the population of immunosuppressed patients. To evaluate these possibilities, serologic tests were carried out:

Tuberculosis serology       negative
Histoplasmosis serology     negative
Thyroid microsomal Ab.      positive (1:50,000 with normal <1:100)

The high titer of thyroid microsomal antibodies suggest that this is a case of idiopathic adrenalitis which probably also includes a component of autoimmune thyroiditis.

The patient was given glucocorticoid and mineralocorticoid replacement therapy, and her symptoms resolved.

Notes

The patient should be instructed to carry an identifying bracelet or card indicating a need for increased steroid dosage during stress or injury. In these patients, failure to give "stress doses" of steroids when needed (e.g., prior to surgery) can precipitate cardiovascular collapse and death.

Once her corticoid status is stable, she should be re-evaluated for adequacy of thyroid function and followed over time. Thyroid replacement therapy may become necessary in the future.