DDx ⬇
- Pigmented nevi
- Ephelides (juvenile freckles)
- Lentigines (senile freckles, liver spots)
- Postinflammatory (eg, acne, atopic dermatitis)
- Chronic venous insufficiency
- Melasma (chloasma)
- Neurofibromatosis (café au lait spots, axillary freckling)
- Hemochromatosis
- Addison's disease
- Acanthosis nigricans
- Hyperbilirubinemia (eg, primary biliary cirrhosis)
- Ochronosis (alkaptonuria)
- Pellagra (niacin deficiency)
- Porphyria cutanea tarda
- Wilson's disease
- Whipple's disease
- Scleroderma
- Vitamin B12 deficiency
- Folate deficiency
- Medications: chloroquine, chlorpromazine, minocycline, amiodarone
- Topicals: benzoyl peroxide, tretinoin, fluorouracil
- Fixed drug eruption to laxatives (phenolphthalein), trimethoprim-sulfamethoxazole, NSAIDs, tetracyclines
- Exogenous pigment exposure: carotenemia, argyria, gold, tattooing, arsenic
- Berloque hyperpigmentation (phototoxicity from citrus or celery)
- Visceral leishmaniasis (kala azar)
- POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes)
Related DDx ⬆