Current State of Delayed Hypersensitivity Reactions to Medications

Matt Krantz, MD

Assistant Professor of Medicine

Vanderbilt University Medical Center

Principles of Delayed Hypersensitivity Testing

Testing Timeline

Concomitant Medications

Specificity of Delayed Testing

Sensitivity of Delayed Testing

Ranges approximate — limited formal longitudinal data for delayed-type reactions

Sensitivity of Delayed Testing by Phenotype

Ranges approximate — limited formal longitudinal data for delayed-type reactions

Sensitivity of Delayed Testing by Timing

Ranges approximate — limited formal longitudinal data for delayed-type reactions

Delayed Intradermal Testing

Drug Concentrations: Immediate vs Delayed

Drug Concentrations: Immediate vs Delayed

Intradermal Setup and Technique

Sites

Injection and Concentrations

Reading

Delayed IDT Reactions: Concentration-Dependent Response

Patch Testing

Concentrations

Sites

Fixed Drug Eruption

Interpretation

Cumulative Detection of Positive Reactions

Patch Testing: Allergic vs Irritant reactions

ELISpot Testing

ELISpot Steps

ELISpot Plate Incubation

ELISpot Interpretation

HLA Naming

Serologic Typing

Sequencing-Based Typing

HLA Testing

Strong HLA Class I assocations with SCAR

HLA Testing

Conclusions

Extra Slide

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