Black hairy tongue treated with traditional Chinese medicine: A case report

Rationale: Black hairy tongue (BHT) is a rare condition that is conventionally managed by discontinuing associated medications or habits and practicing good oral hygiene, including tongue brushing. Previous studies have indicated that black tongue coating is often associated with gastrointestinal discomfort, which traditional Chinese medicine (TCM) could be a potentially effective option for treating this condition with minimal side effects. We present a case of BHT diagnosed and treated within 2 weeks by using TCM methods. Patient concerns: A 73-year-old woman presented with a chief concern of a black tongue that had persisted for 2 weeks and was accompanied by thirst and diarrhea. These symptoms were initially observed during her hospitalization for the treatment of staghorn calculi, xanthogranulomatous pyelonephritis, and urosepsis. Using the "four diagnostic methods" of TCM, we observed that her tongue had a thick black coating surrounded by a thick white coating; her tongue was of medium size with tooth marks, and its body color was light red. Diagnoses, interventions, and outcomes: On the basis of TCM theory, we made a clinical diagnosis of BHT and "spleen Qi deficiency with turbid dampness," which may have been caused by the antibiotic treatment during hospitalization. Subsequently, we administered a Chinese herbal medicine (CHM) formula comprising a combination of Wu-Ling-San () and a modification of Da-Yuan-Yin (). After 2 weeks of CHM treatment, the patient's BHT was nearly eliminated, and the thick white coating and the corresponding symptoms were ameliorated. After 4 weeks of CHM treatment, the BHT was completely resolved. Lesson and conclusion: We present a case of BHT, a benign condition that may be caused by antibiotics. The literature does not contain reports on TCM-based diagnosis and treatment strategies for BHT. Using the 4 diagnostic methods of TCM, we observed that BHT was associated with gastrointestinal symptoms, which is consistent with the TCM theory. Moreover, CHM treatment rapidly relieved BHT and related symptoms without adverse events.