Linezolide-induced hairy tongue.

A 52-year-old male, presented with a 3-week history of hairy tongue feeling, dark discoloration, xerostomia and dysgeusia (Fig. 1a). The symptoms started during a 10-week treatment with Linezolid for post-knee arthroplasty complicated with Methicillin-resistant Staphylococcus aureus infection. Hairy tongue consists of a benign condition related to abnormal keratin build-up in filiform papillae, giving them an elongated hair-like appearance. This defective desquamation prevents normal debridement of the filiform papillae that then collect debris, bacteria, fungi or other foreign materials, worsening the discoloration. Such finding is an uncommon adverse reaction of Linezolid therapy, more likely when long antibiotic treatment is followed [1].

Figure 1:

(a) Hairy tongue during linezolid treatment; (b) Normal tongue 3 weeks after discontinuing Linezolid; (c) Results of the Naranjo Adverse Drug Reaction Probability Scale.

The Naranjo's Adverse Drug Reaction (ADR) Probability Scale (Fig. 1c) resulted in a score of 7 (0–10), which according to the authors, corresponds to a probable ADR [2]. Other known causes of dark hairy tongue such as poor oral hygiene, smoking, alcohol or substance abuse were ruled out. Three weeks after discontinuing Linezolid, all tongue symptoms had improved and only a light yellow discoloration remained, which eventually disappeared (Fig. 1b).