Hyperpigmentation of nails in primary adrenal insufficiency

Fingers of a patient with Addison's disease beneath fingers of an individual with similar baseline skin pigmentation without Addison's disease. In the patient with Addison's disease, there is hyperpigmentation of the skin and increased pigmentation of the distal portion of the nails. The proximal portion of the nails are not hyperpigmented, reflecting the reduction in corticotropin (ACTH) secretion following the initiation of glucocorticoid therapy.