Hamartoma of a digital nerve associated with 'triggering' of the finger.

Figure 1--New tattoo, showing ulceration in the areas of red dye. in the tattoo a few weeks later. In some cases, the primary sensitisation is induced by some other contact with the metal, and the reaction in the tattoo follows or accompanies an attack of contact dermatitis. A patient presented to us with skin ulceration 1 month after a new tattoo. On examination, there was full-thickness skin loss in the areas of the red dye, but no damage in the areas of black, green, yellow or blue dye (Fig. 1). He had a tattoo from 4 years earlier, which was previously asymptomatic. However, this tattoo had shown an inflammatory response following his new tattoo, with only the red pigment being affected (Fig. 2). The response in the earlier tattoo was milder than that in the later one. The wounds were treated with silver sulphadiazine dressings, and healed within 2 weeks. No red pigment remained at the site of the new tattoo, although it was still present at the site of the old tattoo. The primary sensitisation was his original tattoo, and the second tattoo provoked a response at both the new and the old tattoo sites.