# Atypical High-Burden Breakthrough Varicella: A Diagnostic Pitfall in the Two-Dose Vaccine Era

## TL;DR

A fully vaccinated child developed a severe chickenpox-like rash, showing that breakthrough infections can occur and may be misdiagnosed.

## Contribution

This case highlights the diagnostic challenges of atypical breakthrough varicella in fully vaccinated children.

## Key findings

- A fully immunized child presented with a severe rash consistent with varicella.
- The case demonstrates the potential for misdiagnosis of breakthrough varicella as scabies.
- Breakthrough varicella can lead to complications like secondary cellulitis.

## Abstract

We present the case of a seven-year-old fully immunized male who developed an intensely pruritic, generalized maculopapular rash that progressed to vesicles. The patient’s rash was initially diagnosed by his primary care provider as possible scabies and treated with topical permethrin. Our examination revealed a diffuse maculopapular and vesicular exanthem with lesions at various stages of evolution, eventually progressing to secondary cellulitis. The patient’s presentation, consistent with varicella (chickenpox), highlights the diagnostic challenges of breakthrough varicella infection and potential complications in fully vaccinated children. Thus, we highlight the importance of having a high clinical index of suspicion for varicella, even in fully immunized children.