Persistent irritation of the soft tissue around an osseointegrated titanium implant. Case report

Percutaneous implants for hearing aids which are anchored in the bone have a low incidence of skin irritation. We report here the case of a man born in 1958 who had a long period of skin irritation, which was on two occasions associated with bacterial infection with Staphylococcus aureus. Despite local treatment with steroid/antibiotic ointment and skin grafts, episodes of skin irritation recurred, often in association with a relapse of ear drainage. Tests of delayed hypersensitivity to the implant and standard allergens were negative. Morphological and immunohistochemical analysis of the skin after removal of the abutment revealed an intense inflammatory reaction, with polymorphonuclear leucocytes, macrophages, lymphocytes, and HLA-DR expressing cells. In contrast to the inflammatory reaction in the soft tissue, there was a large amount of bone and the degree of bone-implant contact was good.