# Case Report: Localized hyperinflammatory response in the bulla after mosquito bites in a patient with systemic lupus erythematosus

## TL;DR

A patient with lupus had a severe blistering reaction to mosquito bites due to a strong local immune response.

## Contribution

This case highlights a unique hyperinflammatory response to mosquito bites in an autoimmune disease patient.

## Key findings

- Blister fluid had extremely high levels of multiple cytokines, unlike normal serum levels.
- Removing the blister fluid reduced inflammation and resolved the blister.
- The reaction suggests a unique immune response in autoimmune patients after insect bites.

## Abstract

A patient with systemic lupus erythematosus developed localized swelling with blistering after mosquito bites. A complete blood count showed eosinophils were 1.09 × 109/L (13.9%). Total IgE was more than 5,000 KU/L. Examination of the blister fluid showed very high levels of interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, tumor necrosis factor (TNF)-α, interferon (IFN)-α, and IFN-γ cytokines, while these serum cytokine levels were normal. After sterile extraction of the blister fluid, the inflammatory substances were removed, and the blister gradually disappeared. This might be a special manifestation after mosquito bites in a patient with a background of autoimmune diseases. Particular attention should be paid to patients with autoimmune diseases after insect bites.