Eosinophilic esophagitis and food allergies: A US National Analysis

Eosinophilic Esophagitis (EoE) and food allergies are closely intertwined. A recent US national analysis, leveraging data between 2016 and 2022, provides critical insights into the relationship between EoE and IgE-mediated food allergies such as milk, egg, peanut, and seafood allergies. Here is a detailed breakdown of the findings:

### **Study Objective**

The study aimed to evaluate the association between EoE and specific food allergies using a large inpatient dataset. EoE is a chronic, immune-mediated esophageal disease driven by eosinophil inflammation, often triggered by food antigens. However, the exact relationship between specific food allergies and EoE had not been fully quantified prior to this study.

### **Study Design and Dataset**

• **Design**: Retrospective cross-sectional analysis.
• **Dataset**: National Inpatient Sample (NIS), the largest publicly available all-payer inpatient database in the US.
• **Study Period**: 2016–2022.
• **Population**: Included all US hospitalizations with a diagnosis of EoE (ICD-10 code K20.0) and comorbid food allergies (milk, egg, peanut, seafood).

### **Key Findings**

#### **Sample Size**

• Out of 46,575 EoE hospitalizations:
• **Milk allergy**: 1,765 cases (3.79%)
• **Egg allergy**: 1,535 cases (3.30%)
• **Peanut allergy**: 1,460 cases (3.13%)
• **Seafood allergy**: 1,185 cases (2.54%)

#### **Demographics**

• **Age**: Mean age of EoE patients was 36.4 years. However, patients with food allergies were significantly younger:
• Milk, egg, and peanut allergy cases: Around 13–15 years.
• Seafood allergy cases: Around 22 years.
• **Sex Distribution**: Males constituted the majority of EoE cases (65–68%), confirming a strong male predominance.
• **Racial Disparities**: White patients had the highest rates of EoE. Black and Hispanic patients had lower odds of EoE (adjusted odds ratio [aOR] of 0.47 and 0.45, respectively), suggesting potential disparities in diagnosis or healthcare access.

#### **Socioeconomic and Insurance Trends**

• **Income**: Patients from the highest household income quartile (≥$86,000) had increased odds of EoE (aOR 1.79), indicating differences in healthcare access and diagnosis.
• **Insurance**: Privately insured (aOR 3.09) and Medicaid-covered (aOR 2.34) patients had higher odds of EoE compared to Medicare patients, possibly due to differences in healthcare utilization and referral pathways.

#### **Geographic Trends**

• The highest proportion of EoE cases with food allergies was reported in the South (35–41%), followed by the Midwest and Northeast. This may reflect regional diagnostic or environmental influences.

#### **Hospital Characteristics**

• Most EoE admissions occurred in large metropolitan hospitals (over 60%), suggesting better access to diagnostic procedures like endoscopy in high-volume centers.

#### **Age-Related Trends**

• **Pediatric patients (<18 years)**: Had the highest likelihood of EoE.
• **Adults aged 45–64 and ≥65 years**: Had significantly reduced odds of EoE (aOR 0.18 and 0.06, respectively).

#### **Food Allergy-Specific Associations**

• Logistic regression revealed strong associations between EoE and specific food allergies:
• **Milk allergy**: Strongest association (aOR 7.52, p<0.001).
• **Egg allergy**: aOR 4.77.
• **Peanut allergy**: aOR 3.94.
• **Seafood allergy**: aOR 2.57.

#### **Temporal Trends**

• Between 2016 and 2022, EoE-related hospitalizations increased significantly (from 5,620 to 7,664 cases). However, the relative proportions of specific food allergies remained stable.

#### **Sex-Specific Findings**

• Female patients with food allergies had lower odds of EoE (aOR 0.52, p<0.001), reinforcing the male predominance in EoE prevalence.

#### **Comorbidity Impact**

• EoE patients with fewer comorbidities (Charlson Comorbidity Index = 1) were more likely to have food allergy-related EoE (aOR 1.58), suggesting that EoE often occurs in otherwise healthy individuals.

#### **Clinical Insights**

• **Milk Allergy**: Milk allergy’s strong association with EoE supports the "cow’s milk hypothesis," where milk proteins are a predominant trigger for EoE. This validates dietary elimination approaches like the one-food elimination diet (1FED).
• **Screening Importance**: Early screening for EoE in children with known food allergies, particularly males and those with milk sensitivity, is crucial to prevent chronic inflammation and fibrosis.

### **Clinical Implications**

1. **Tailored Dietary Management**: The study highlights the need for personalized dietary interventions for EoE patients with food allergies, especially milk sensitivity.

2. **Early Detection**: Screening high-risk groups—children, males, and those with milk allergy—can prevent long-term complications like esophageal fibrosis.

3. **Equitable Access**: Addressing racial and socioeconomic disparities in diagnosis and management is essential for improving patient outcomes.

4. **Regional Focus**: Understanding geographic trends can help allocate resources to regions with higher EoE prevalence.

### **Conclusions**

This national analysis demonstrates a strong, statistically significant link between EoE and specific food allergies—especially milk, egg, peanut, and seafood. The findings emphasize the importance of early diagnosis, tailored dietary management, and equitable healthcare access to improve outcomes for EoE patients. Milk allergy, in particular, stands out as a predominant trigger, validating dietary elimination strategies and underscoring the need for focused clinical interventions.