# Invasive Ureaplasma infection in a pediatric patient: a case report

## TL;DR

A teenager with weakened B-cell immunity due to treatment developed a rare invasive Ureaplasma infection, which was successfully treated with antibiotics after molecular testing.

## Contribution

This case report highlights Ureaplasma spp. as a potential cause of invasive infection in B-cell depleted patients and emphasizes the role of molecular diagnosis.

## Key findings

- A 17-year-old B-cell depleted patient developed disseminated Ureaplasma urealyticum infection with multifocal abscesses.
- Molecular testing identified Ureaplasma in joint fluid, and treatment with doxycycline and levofloxacin resolved symptoms.
- The case underscores the importance of considering Ureaplasma in immunosuppressed patients with complex symptoms.

## Abstract

Ureaplasma spp. are a rare cause of invasive disease outside of the neonatal period. Recent studies have shown that immunosuppression with B-cell depleting therapies, such as rituximab or obinutuzumab, can increase the risk of invasive infection. We present a case in which a patient receiving B-cell depleting therapy for anti-neutrophil cytoplasmic antibody-associated vasculitis and pauci-immune nephritis was diagnosed with disseminated, invasive Ureaplasma infection.

A 17-year-old female with documented B-cell depletion presented to the emergency department from the pediatric infectious disease clinic with persistent shoulder pain. Within the first month of admission, the patient developed multifocal abscesses with joint involvement and an echodensity resembling a possible vegetation, all of which were unresponsive to broad-spectrum antibiotics. A broad-spectrum polymerase chain reaction test detected Ureaplasma urealyticum in aspirated joint fluid from multiple anatomic sites. Clinical improvement occurred after initiation of combination therapy with intravenous doxycycline and levofloxacin.

We describe a patient with documented iatrogenic B cell depletion presenting with a disseminated, multifocal invasive Ureaplasma infection including osteoarthritis, cellulitis, and soft tissue abscess. Following a 6-week course of levofloxacin, the patient’s C-reactive protein, fever, and pain resolved without further evidence of disease. This case report highlights the importance of considering disseminated, invasive Ureaplasma spp. when evaluating B-cell depleted patients with challenging multifocal symptom complexes. In addition, this case report highlights the critical role of molecular diagnosis in identifying this fastidious pathogen.