RT Journal Article SR Electronic T1 Minocycline-induced black hairy tongue and skin hyperpigmentation JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e253811 DO 10.1136/bcr-2022-253811 VO 16 IS 4 A1 Kazuhide Takata A1 Fumihito Hirai YR 2023 UL http://casereports.bmj.com/content/16/4/e253811.abstract AB