Kratom-Induced Hyperpigmentation: An Emerging Clinicopathologic Pattern.

Kratom (Mitragyna speciosa) is a commonly used over-the-counter supplement with opioid-like and dopaminergic activity. Cutaneous side effects have been incompletely characterized; only limited case reports describe its associated hyperpigmentation. We describe two cases of kratom-induced photodistributed brown-gray patches with biopsies that show circular, orange-brown granules in the dermis that stain positive with Fontana-Masson and negative for iron. In conjunction with existing literature, our cases suggest a possible distinct clinicopathologic pattern for which kratom use can be suspected.