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. (Fig.1a).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]