Endocrine Abstracts

Introduction: Addison’s disease was first described in 1855 by Thomas Addison as a result of adrenal insufficiency. It is most common in females aged 30–50 years. Symptoms are often non specific.Weakness and weight loss are universal features of Addison’s disease. It can present to a dermatologist in different ways. We present a case of a young female who reported to dermatology outdoor with a typical melasma-like eruption over her face.

Case report: A 23-year-old young woman presented to our clinic with 5 months history of progressive facial pigmentation, gradually worsened. She noted a weight loss of 8 kg during this period. She also reported that previous Ramadan fasting was a challenge for her. On examination she was found to be weak with marked pallor. Dermatological examination revealed typical melasma-like pigmentation over bridge of the nose and prominence of the cheeks. There was no pigmentation in palmar creases, flexures, nipples, knuckles, genitalia or oral mucosa. Systemic examination was unremarkable. Our major diagnostic doubt was between diagnosing classic melasma or Addison’s disease. Therefore, we requested laboratory tests. Blood chemistry tests revealed low plasma cortisol associated to hyponatraemia and hyperkalaemia. Furthermore, a short synacthen tes was requested to confirm adrenal insufficiency, in which impaired response to adrenocorticothropin hormone was found. MRI of the adrenal glands showed absence of any masses or swellings that could mimic a neoplasm producing ACTH. On the basis of the above findings, a diagnosis of Addison’s disease was made.

Discussion: Addison’s disease is a primary adrenal failure caused by infiltrative or autoimmune processes. Hyperpigmentation of the skin is considered a hallmark of Addison’s disease, related to ACTH melanogenesis action. It may involve skin, oral cavity, conjunctiva and genitalia. It is more evident in areas exposed to the sun and under mechanical stimulation: palmar creases, knuckles, flexural areas, areolas of nipples, scars and genital mucosa. Melasma-like pigmentation without involving any other area of the body is an uncommon finding in Addison’s disease. Our patient initially presented with only melasma like hyperpigmentation and Addison’s disease were never thought of at that time, but when it was soon followed by other suggestive manifestations we correlated it and considered it to be one of dematological presentation of the disease.

Conclusion: Every melasma-like pigmentation is not always melasma. We, dermatologists, should have a high index of suspicion for a rare and potentially dangerous medical illness i.e. Addison’s disease.