# AI建议对贝类过敏的患者避免所有CT造影剂，混淆碘过敏与贝类过敏

- **ID:** `medical/contrast-ct-allergy-history`
- **领域:** medical
- **类别:** data_error
- **错误码:** `CONTRAST_SHELLFISH_FALSE`
- **验证级别:** ai_generated
- **修复率:** 90%

## 根因

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。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| ehr_system_2023.2 | active | — | — |
| radiology_contrast_manual_9th_ed | active | — | — |
| allergy_module_v4.1 | active | — | — |

## 解决方案

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.`
   ```

## 无效尝试

- **** — Patient or clinician believes historical 'iodine allergy' label is valid, perpetuated by outdated medical records (75% 失败率)
- **** — Patient self-diagnoses as 'allergic to contrast' because they ate shrimp before a previous scan and had a reaction (70% 失败率)