What made the language of this woman black and "hairy"?

A 55-year-old woman became black and hairy after the woman was treated with antibiotics for an infection following a car accident.

According to a report published yesterday (Sept. 6) in the New England Journal of Medicine, the accident broke both her legs and caused her to develop a polymicrobial infection – an infection caused by more than one microbe.

To treat the infection, doctors have initiated two distinct antibiotics: meropenem and minocycline. According to the report, after a week, the woman reported feeling nauseous and having a bad taste in her mouth. She also had another more striking symptom: her tongue had turned black and hairy. [7 Weirdest Medical Conditions]

This condition, perhaps unsurprisingly called "black hairy tongue," is not harmful, says the report, and is caused by the enlargement and growth of small bumps on the surface of the tongue. According to the Encyclopedia of Neuroscience, these bumps, called filiform papillae, unlike other taste buds on the tongue, do not contain taste buds. Instead, they help grab food, according to an article published in 2016 in the journal Developmental Dynamics.

The black hairy tongue could be caused by a number of factors, including certain medications, smoking, irritating mouthwashes or poor oral hygiene. In the case of the woman, doctors suspect that the antibiotic minocycline is to blame, according to the report.

Indeed, when doctors replaced minocycline with another antibiotic and advised him to practice good oral hygiene, his tongue returned to normal in one month.

Originally published on .