Erythematous cutaneous nodules caused by adulterated cocaine

In the 1989 study, researchers reported on the development of erythematous cutaneous nodules in individuals who had injected adulterated cocaine. Two cases were presented: a 32-year-old woman and a 45-year-old man, both of whom developed nodules at the sites of cocaine injection. Biopsies of these nodules revealed birefringent talc crystals, which induced a cell-mediated immune response characterized by T lymphocytes rather than the macrophage infiltration typical of a foreign body response. Immunocytochemistry confirmed the presence of T cell markers (CD3+, CD5+, CD4+, and CD8+), and immunofluorescence showed granular deposits of IgM and C3 in the blood vessels of one patient. The study concluded that the talc crystals found in street-grade cocaine can lead to hypersensitivity granulomas, and the immune response to these crystals is enhanced rather than presenting as a typical foreign body reaction. The study also suggested that cocaine might directly enhance the immune response, contributing to the development of immunogenic talc granulomas.