Delayed immunologic complications due to injectable fillers by unlicensed practitioners: our experiences and a review of the literature.

For a number of years, there have been unauthorized practitioners who have been illegally injecting substances. In this series of cases, delayed type hypersensitivity reactions occurred after having unknown material fillers injected by unlicensed practitioners. When injecting an unknown material, there can be a severe immune reaction due to the unknown number of antigens in the material, and therefore may act as a much stronger superantigen than conventional filler materials. It appears that the adverse effects in these cases are more severe and have tendency to break out after a longer period of time in comparison with those caused by approved fillers, likely due to operative technique and use of unverified materials. It is important to recognize the danger of such illegal procedures and to increase awareness of the public, as this has evolved into a significant public health issue.