Subungal Discoloration with Tetracycline Long Term Use

[Guide]

Subungal Discoloration with Hemotoma or Disease
A subungal discoloration usually is associated with a hematoma on finger or toe nails. [1] There are numerous images associated showing this available in a google search.

However, subungal discoloration can be associated with disease. "Subungual discoloration carries a broad differential including infectious, inflammatory, metabolic, malignant or systemic diseases. Knowledge of this side effect is crucial in order to avoid unnecessary testing in determining the etiology of the subungual discoloration. Knowledge of this side effect is crucial in order to avoid unnecessary testing in determining the etiology of the subungual discoloration." [2]

Subungal Discoloration with Tetracycline Long Term Use
The authors of one paper on this subject explain that it is important to let patients know that long term use of tetracyclines, i.e., doxycycline, minocycline, for rosacea this subungal discoloration may be one of the side effects and risks. The report states, "We report on a case of a patient who has been on long-term minocycline use for adult acne management. He was initially on minocycline for six years, but due to minocycline-induced hyperpigmentation of his ears and fingernails, he had switched to doxycycline. One year later, the skin hyperpigmentation of the ears regressed; however, the blue subungual hyperpigmentation of his hands progressively become more prominent without any other significant symptoms." [2]

End Notes

[1] Subungual hematoma, Wikipedia

[2] Cureus. 2020 Apr 24;12(4):e7810
Out of the Blue: A Case of Blue Subungual Discoloration Associated with Prolonged Tetracycline Use.
Ahmad Y, Boutros H, Hanna K