ESPE Abstracts

Introduction: Adrenal insufficiency (AI) leads to a diminished production of steroid hormones. AI is subdivided into a primary and a secondary form. In primary AI, the underlying defect affects the adrenal gland itself resulting in a low steroid production and an overproduction of adrenocorticotropic hormone (ACTH). On the contrary, the cause of secondary AI lies in the pituitary, leading to a reduced production of ACTH and consecutively to a reduced excretion of corticosteroids. In primary AI, which is also called Addison’s Disease or hypocortisolism, low serum cortisol levels lead – due to negative feed-back mechanisms – to an increase in ACTH-levels. ACTH is generated by cleavage of proopiomelanocortin (POMC) into ACTH, melanocyte-stimulation hormone (MSH) and beta-lipoprotein. ACTH undergoes further cleavage to produce alpha-MSH. This is the most important MSH for skin pigmentation leading to hyperpigmentation of the skin.

Case report: A 16-year old girl came to our outpatient clinic because of hyperpigmentation of the skin. She reported to have a very dark skin without sun exposition for one year. Especially palmar creases, nipples and armpits were affected. Moreover, she reported tiredness and craving for salt. Longterm history was without pathological findings, family history showed an increase in autoimmune diseases (coeliac disease, pernicious anaemia).

Clinical diagnostics: Laboratory values showed low cortisol (16.6 ng/ml) whereas ACTH and Renin were elevated (1250 pg/ml and 506.5 μU/ml, respectively). Parathyroid hormone and electrolytes were in normal range. ACTH stimulation test showed an insufficient increase in cortisol, which – in combination with elevated 21-hydoxylase-antibodies – confirmed the diagnosis of Addisons’s Disease due to autoimmune adrenalitis. Genetic testing of the AIRE gene turned out negative.

Course of disease: An oral therapy with hydrocortisone and fludrocortisone was started. The well-being of the patient improved, as well as fatigue and blood pressure. The colour of the skin became considerably lighter.

Conclusions: Whereas tuberculosis used to be the most common cause for Addison’s Disease in former days, autoimmune adrenalitis is the major cause nowadays. It can appear isolated or in coincidence with the APECED Syndrome (Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy). It is associated with mutations in the AIRE gene which plays an important role in immune tolerance.