Desensitization of Drug-Allergic Patients

Only immediate type hypersensitivity drug reactions involving IgE antibodies and/or a mast cell-mediated mechanism are considered eligible for desensitization. 

Note that desensitization to a drug does not result in long-term tolerance to the adverse effects of the drug and this therefore means that 

6 Delayed-Type (Type IV) Hypersensitivity Drug Reactions 

Unlike types I, 11, and III hypersensitivities, which are mediated by antibodies, delayed or cell-mediated hypersensitivity, classified as type rv, is mediated by antigen-specific effector T cells and this means that the hypersensitivity response can be transferred by purified T cells or a cloned T cell line. Again in contrast to an immediate reaction, a delayed-type hypersensitivity reaction develops over a period of 24-72 h. Delayed hypersensitivity responses have been used for many years to assess patients cell-mediated immunity by the induction of induration and erythema 48-72 h after intradermal injection of so-called recall antigens from Mycobacterium tuberculosis, Candida and Trichophyton species, and tetanus toxoid. 

1 The Cellular Basis of Type IV Hypersensitivity Cutaneous Drug Reactions 

---