This image of the dorsum of the tongue of a 42-year-old African American woman shows parallel linear black coatings.

This patient reported having taken a “swig” of Kaopectate the evening before she came to the office. She noticed that her tongue was black while brushing her teeth the next morning. She brushed her tongue with toothpaste and rinsed her mouth with hydrogen peroxide. After she repeated this treatment for 2 days the black coloration was no longer present.

Kaopectate contains bismuth subsalicylate, as does Pepto-Bismol. Bismuth can stain the tongue black and is associated with black stools. Black tongue, or lingua nigra, may be associated with papillae hypertrophy. Black tongue without papillae hypertrophy can be associated with tobacco abuse, crack cocaine smoking, lansoprazole, oral bismuth subsalicylate (suspension or tablets), methyldopa, minocycline, and hydroxychloroquine.

Black “hairy” tongue gets its name from the hypertrophied filiform papillae on the dorsum of the tongue, believed to be the result of an antibiotic-induced imbalance of native bacteria.

 Other predisposing factors include cigarettes, psychotropic drug use, or 

Kaopectate originally contained kaolinite and pectin. In the late 1980s, the primary ingredient was changed to attapulgite in the US; in 2004 bismuth subsalicylate replaced attapulgite but the Kaopectate brand name was retained.

The kaolin and pectin combination is still available under the brand names Kao-Spen, Kaopectolin, and Kaolin with Pectin. In some countries Kaopectate is still made with kaolin and pectin.

Treatment of both forms of black tongue (with or without papillae hypertrophy) includes toothbrush scrubbing with or without toothpaste or hydrogen peroxide, or applications of Retin-A gel (tretinoin) or 40% aqueous solutions of urea or papain. And, of course, known causative or associated factors should be eliminated.

. 10th ed. Philadelphia: Lippincott Williams & Wilkins; 2010:363.

Andrew’s Clinical Dermatology: Diseases of the Skin

. 11th ed. Saunders Elsevier, Inc; 2011:789.

Skin Diseases

After a “swig” of  Kaopectate, this patient noticed tongue discoloration. Is this coincidental, or is there a clinical connection? 

Black Coating on a Woman’s Tongue