Causes of Skin Bronzing: Understanding Potential Health Conditions

Skin bronzing (hyperpigmentation with a bronze/gray tint) can signal underlying systemic disease.

Medical Causes

1. Addison’s disease (primary adrenal insufficiency): ACTH/MSH elevation → melanocyte stimulation. Classic sign.
2. Hemochromatosis: Iron deposition in skin + melanin → bronze/gray discoloration.
3. Nelson’s syndrome: Post-adrenalectomy for Cushing’s; ACTH-secreting pituitary tumor → hyperpigmentation.
4. Pituitary adenoma (ACTH-secreting): Ectopic ACTH → bronzing.
5. Secondary adrenal insufficiency: Usually pale, but can have bronzing if from pituitary tumor with ACTH excess.
6. Pityriasis versicolor: Fungal (Malassezia) infection; fine scaly patches, not true bronzing.

Other Considerations

• Medications: minocycline, amiodarone, antimalarials.
• Chronic sun exposure (photoaging).
• Porphyria cutanea tarda.

Action

New, unexplained bronzing warrants medical evaluation (cortisol, ACTH, iron studies, pituitary imaging).