The authors present the case of a non-smoker, 40-year-old woman, with hidradenitis suppurativa (IHS4 9). When she presented for deroofing surgery she complained of an asymptomatic dark pigmentation of her tongue. She recalled three similar self-limited episodes, that coincided with doxycycline cycles, but denied a similar reaction when she took minocycline. A diagnosis of hairy black tongue induced by doxycycline was made and the patient was reassured (Figure 1). Dermoscopy with DermLite DL4 (CREUP TECHNOLOGIES LTD., Shenzhen, China), revealed brownish hair-like elongation of filiform papillae with whitish lingual papillae. A fungal direct or culture exam was not undertaken. Complete resolution occurred in a few days.
Black hairy tongue is a benign, self-limiting, usually asymptomatic lesion, characterized by the presence of elongated filiform papillae of the dorsum of the tongue. Known risk factors include poor oral hygiene, tobacco, and antibiotics. The pathophysiology remains unknown but a change in microbiome has been suggested. Dermoscopy can aid in the diagnosis of this disorder. As far as the authors are concerned, this is the second article depicting these dermoscopic features.
All data underlying the results are available as part of the article and no additional source data are required.
The authors declare that they have no conflict of interest to disclose.
This work received no funding.
Figure 1: A diagnosis of hairy black tongue induced by doxycycline.