# Possible Resolution of Food Allergies Following Tocilizumab-Induced Remission of Juvenile Idiopathic Arthritis

## TL;DR

A child with juvenile arthritis and severe food allergies went into remission after treatment with tocilizumab, suggesting a link between IL-6 inhibition and both conditions.

## Contribution

This case suggests that IL-6 inhibition may modulate both autoimmune and allergic pathways, offering a novel therapeutic insight.

## Key findings

- Tocilizumab treatment led to remission of both juvenile idiopathic arthritis and IgE-mediated food allergies.
- Controlled food challenges confirmed sustained tolerance to previously allergenic foods.
- The resolution of peanut allergy, alongside milk and egg allergies, was temporally linked to IL-6 inhibition.

## Abstract

This case report describes a unique instance of a four-year-old Ashkenazi Jewish male with systemic juvenile idiopathic arthritis (JIA) and severe IgE-mediated food allergies who achieved complete remission of both conditions following treatment with tocilizumab, an IL-6 receptor antagonist. The patient initially presented with anaphylactic reactions to peanuts, eggs, and cow’s milk, confirmed by positive skin prick tests and elevated specific IgE (sIgE) levels. Systemic JIA symptoms, including daily fever spikes, evanescent rash, and polyarticular arthritis, developed shortly thereafter. After inadequate response to standard therapies, tocilizumab was initiated, resulting in complete remission of JIA symptoms and unexpected resolution of food allergies. Repeat allergological evaluations, including skin prick tests, sIgE levels, and controlled oral food challenges, confirmed sustained tolerance to previously allergenic foods. The dual remission observed in this case suggests that interleukin-6 (IL-6) inhibition may modulate shared immunological pathways underlying autoimmune and allergic diseases. IL-6 is a key cytokine in both conditions, promoting Th17-mediated inflammation in JIA and Th2-mediated allergic responses, including IgE production and mast cell activation. While the spontaneous resolution of food allergies, particularly to milk and eggs, is well-documented in pediatric populations, the resolution of peanut allergy, in this case, is highly unusual and temporally associated with tocilizumab treatment. This case raises the possibility that IL-6 inhibition may play a role in modulating autoimmune and allergic responses, warranting further investigation into the interplay between these pathways.