Primary Adrenal Insufficiency (Addison's Disease) Presenting as Sun Tan-Like Skin Pigmentation: A Case Report

Primary adrenal insufficiency (PAI), also known as Addison's disease (AD), is a condition resulting from adrenal gland diseases that lead to glucocorticoid and/or mineralocorticoid deficiency, in addition to androgen deficiency in females. Here, we report a 40-year-old male indoor worker with an insignificant past medical history who presented to the dermatology clinic with a history of asymptomatic, slowly progressive skin hyperpigmentation for the past three years. It was associated with fatigue and weight loss. Skin examination revealed diffuse, non-scaly hyperpigmented patches on his face, dorsae of the hands, and palms. Early morning cortisol and adrenocorticotropic hormone (ACTH) serum levels were 1.00 mu g/dl (5.0-19.4 mu g/dl) and 2000 pg/mL (7.2-63.3 pg/mL), respectively. Based on the above clinical and laboratory findings, a diagnosis of AD was made. The patient was started on the following medications for 14 days: hydrocortisone 20 mg in divided doses (15 mg am/5 mg pm) and fludrocortisone 0.1 mg once daily (od). On the second visit, the patient's symptoms (both the cutaneous hyperpigmentation and fatigue) significantly improved, but he was complaining of edema in both upper and lower limbs, so the dose of fludrocortisone was reduced to 0.05 mg od.