Black hairy tongue treated with oral antibiotics: a case report.

Abstract

To the Editor: Black hairy tongue (BHT), also known as lingua villosa nigra, is a rare but benign and painless condition caused by defective desquamation and reactive hypertrophy of the filiform papillae of the tongue.1, 2 BHT occurs more frequently in elderly adults than in younger individuals and is rare in children.1 It is usually asymptomatic, but it may cause nausea, a metallic taste in the mouth, halitosis, and a sensation of fullness in the back of the mouth.1-3 A number of etiologies for this condition have been proposed, including use of topical or systemic antibiotics, use of psychotropic agents, hyposalivation, trigeminal neuralgia, poor oral hygiene, smoking, regular coffee consumption, and infection.2, 4-6 The optimal treatment for BHT is unclear. We report a 74-year-old woman with BHT who was successfully treated with a short course of oral antibiotics. A 78-year-old woman presented with loss of appetite and abnormal sensation in both legs. She was noted to have a black coating on the dorsal surface of her tongue consistent with BHT (Figure 1A), which was asymptomatic and had been present for 4 years. She was not edentulous. She used herbal medicines and had been taking a proton pump inhibitor for 3 months, which had improved her appetite but had not changed her BHT. She did not have a history of drinking coffee, smoking cigarettes, or taking antibiotics or other medications that may have caused BHT. She had an upper respiratory tract infection with low-grade fever, sore throat, and a small amount of purulent sputum and was prescribed oral antibiotics (cefditoren pivoxil, 300 mg/d for 5 days) at a private clinic. After 2 days of antibiotic therapy, her tongue discoloration resolved, and after 5 days, the hypertrophy of the filiform papillae resolved (Figure 1B). Her respiratory symptoms resolved after 4 days. No culture of the BHT was performed. She did not brush the surface of her tongue or gargle with iodine, which can be used to treat BHT. It is thought that bacterial or yeast infection causes the discoloration of the dorsal tongue in BHT.6 Prevention and treatment of BHT includes avoiding risk factors and practicing good oral hygiene, especially brushing of the posterior tongue. Several topical and systemic therapies have been used for this condition, including corticosteroids, antifungals, and vitamin preparations, but none of these treatments is recommended because the condition is benign. Previous reports suggested that Bacillus subtilis or candida infection may cause BHT.7-9 Based on the results of animal experiments, it has been suggested that Bacillus subtilis varietas niger infection causes BHT.8 It has also been reported that Bacillus subtilis infection caused BHT.9 A previously reported case of BHT was successfully treated using a short course of an antifungal medication (fluconazole).6 Cefditoren pivoxil is a third-generation oral cephalosporin with a broad spectrum of activity against pathogens, including gram-positive and -negative bacteria, that are resistant to hydrolysis by many common beta-lactamases and may be effective for the treatment of Bacillus subtilis infection. This case supports previous reports that bacterial infection can cause BHT, because the short course of oral antibiotics resulted in dramatic improvement, but it is likely that BHT also has several other causes. Although prolonged antibiotic therapy may cause BHT, this case shows that a short course of antibiotics with activity against the causative pathogen may be effective for the treatment of BHT caused by bacterial infection. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: All authors contributed to this paper. Sponsor's Role: None.