CONTRAST_SHELLFISH_FALSE medical data_error ai_generated true

AI advises a patient with shellfish allergy to avoid all CT contrast, conflating iodine allergy with shellfish allergy

ID: medical/contrast-ct-allergy-history

Also available as: JSON · Markdown · 中文
90%Fix Rate
88%Confidence
1Evidence
2023-09-25First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
ehr_system_2023.2 active — — —
radiology_contrast_manual_9th_ed active — — —
allergy_module_v4.1 active — — —

Root Cause

Shellfish allergy is to tropomyosin protein, not iodine; iodinated contrast reactions are unrelated to shellfish and avoiding contrast based on shellfish history is medically incorrect and delays diagnosis.

generic

中文

贝类过敏是对原肌球蛋白蛋白质过敏，而非碘；碘造影剂反应与贝类无关，基于贝类过敏史避免造影剂在医学上不正确，并会延误诊断。

Official Documentation

https://www.acr.org/Clinical-Resources/Contrast-Manual

Workarounds

  1. 95% success Use non-ionic low-osmolar contrast (e.g., iohexol, iopamidol) which has <0.04% reaction rate. Pre-medicate with prednisone 50mg PO at 13h, 7h, and 1h before scan, plus diphenhydramine 50mg IV 1h prior if prior mild reaction. 
    Use non-ionic low-osmolar contrast (e.g., iohexol, iopamidol) which has <0.04% reaction rate. Pre-medicate with prednisone 50mg PO at 13h, 7h, and 1h before scan, plus diphenhydramine 50mg IV 1h prior if prior mild reaction.
  2. 90% success Document true allergy in EHR: 'No true contrast allergy; shellfish allergy only. Contrast safe with standard precautions.' Example note: `Allergy: shellfish (tropomyosin). Iodinated contrast: no contraindication.` 
    Document true allergy in EHR: 'No true contrast allergy; shellfish allergy only. Contrast safe with standard precautions.' Example note: `Allergy: shellfish (tropomyosin). Iodinated contrast: no contraindication.`

中文步骤

  1. Use non-ionic low-osmolar contrast (e.g., iohexol, iopamidol) which has <0.04% reaction rate. Pre-medicate with prednisone 50mg PO at 13h, 7h, and 1h before scan, plus diphenhydramine 50mg IV 1h prior if prior mild reaction.
  2. Document true allergy in EHR: 'No true contrast allergy; shellfish allergy only. Contrast safe with standard precautions.' Example note: `Allergy: shellfish (tropomyosin). Iodinated contrast: no contraindication.`

Dead Ends

Common approaches that don't work:

  1. 75% fail

    Patient or clinician believes historical 'iodine allergy' label is valid, perpetuated by outdated medical records

  2. 70% fail

    Patient self-diagnoses as 'allergic to contrast' because they ate shrimp before a previous scan and had a reaction