Endocrinology Cushing Adrenal

Hyperpigmentation

Hyperpigmentation can be a sign of ACTH-independent (primary) adrenal insufficiency. High levels of ACTH found in these patients stimulate the melanocortin-1 receptor in the skin, resulting in hyperpigmentation. It tends to first occur in areas of the skin under pressure, including elbows, knuckles, palmar creases, lips, and buccal mucosa.
Endocrinology

Patient 2

This is a previously healthy young woman who was diagnosed with primary adrenal insufficiency. Hyperpigmentation can be seen over the knuckles. The astute observer will also note that the patient has about 3 mm of fingernail growth since she last painted her nails. Fingernails grow at rate of approximately 1 mm per week, and so the illness was predicted to have began approximately 3 weeks prior to presentation, which was corroborated by the patient.