Enfermedad de Addison en una gemela de 19 meses

addison？s disease or primary adrenal insufficiency is a clinical entity in which the adrenal cortex secretes insufficient amounts of glucocorticoids, mineralocorticoids and androgens due to an adrenal noxa. we report the case of a nineteen months old twin girl, who presented with a history of chronic fatigue, wasting, vomiting, hyporexia and hyperpigmentation in lips and gums. the symptoms continued for two months and worsened until the proper diagnosis was made and the treatment was established. this case represents one of the youngest patients diagnosed with addison？s disease in our country, as well as an early age of presentation compared to the average age of diagnosis for this disease. we provide a comparison between the patient and her healthy twin sister, so the signs of the disease are even more evident.