Mystery behind labial and oral melanotic macules: Clinical, dermoscopic and pathological aspects of Laugier Hunziker syndrome Pathology Outlines Melanotic macule Abuse of laxatives and melanosis coli Melanosis coli is dark brown black pigmentation of colorectal mucosa associated with chronic use of laxatives containing anthraquinone. Examples of such laxatives include senna and rhubarb derivatives. Clinical Importance: There is no association Pigmented Lesions of the Oral Mucosa Pocket Dentistry Mystery behind labial and oral melanotic macules: Clinical, dermoscopic and pathological aspects of Laugier Hunziker syndrome