Allergic clinical symptoms and distribution of stimulation index of drug lymphocyte stimulation test for local anesthetics

Objective: The Drug Lymphocyte Stimulation Test (DLST), recognized for its safety as an allergy diagnostic modality, has been acknowledged for its utility in diagnosing drug-induced pathological conditions. However, reports elucidating DLST outcomes concerning local anesthetics are notably scarce.

Materials and methods: An exhaustive analysis was conducted on the DLST results pertaining to local anesthetics derived from 571 patients presenting with suspected allergies to these specific agents.

Results: Remarkably, Stimulation Index (SI) > 1.8 was discerned in 11.4% and 7.8% of patients exhibiting hives or swelling subsequent to the administration of local anesthetics, surpassing the incidence observed in those experiencing post-injection discomfort. Additionally, SI > 3.0 was observed in 3 cases with lidocaine, 3 cases with prilocaine, and 1 case with mepivacaine. The distribution of SI exhibited a non-normal pattern for all three tested local anesthetics. Noteworthy is the case of a singular patient registering an SI of 1.84, who also yielded a positive challenge test, conclusively confirming an allergy to lidocaine.

Conclusions: The DLST, holding promise as a potentially invaluable tool in identifying the causative factors behind adverse reactions to dental local anesthetics, lacks sufficient evidence to substantiate its efficacy definitively at present.

Clinical relevance: DLST, coupled with intradermal testing and challenge testing, may be elucidated in patients exhibiting indicators of suspected local anesthetic allergy.