What’s this blue dot on this man’s knee?
72 year old man with a blue-gray macule on his knee. He was told by his doctor that it was a blue nevus, but he begs to differ. It has been there almost all his life- at least since the 3rd grade.
What is your diagnosis?
Diagnosis:
Graphite Tattoo (pencil lead tattoo)
He vividly remembers that in the 3rd grade he was teasing a classmate and they “jabbed me with their pencil”!
Lead tattoos from pencils are very common. During a week in practice I took an informal survey and found that approximately 5% of my patients had them from their school days. They are of no health concern and are often diagnosed as a blue nevus, as was the case for this patient. Ironically, the next year, he also accidentally poked himself with his own pencil creating a second lead tattoo near the first one, if you take a close look a bit to the right.
There are other foreign body tattoos that can cause allergic reactions (click here to review the June 2006 case of the month) or reactive granulomas (keep an eye open on future cases of the month for a silicone granuloma).
Of courser, the take home point here is that any lesion that is suspicious for malignancy, changing rapidly, no history of trauma, or bleeding without provocation should be evaluated promptly and carefully.
Charles E. Crutchfield III, MD
Clinical Adjunct Associate Professor of Dermatology
At the
University of Minnesota Medical School
Medical Director, Crutchfield Dermatology
www.CrutchfieldDermatology.com
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