# Musculoskeletal Coccidioidomycosis in the Setting of Adalimumab: A Case Report

## TL;DR

A 53-year-old woman on adalimumab developed a rare fungal infection affecting her musculoskeletal system, highlighting risks of immunosuppressive drugs.

## Contribution

Reports a rare case of musculoskeletal coccidioidomycosis in a patient on adalimumab, emphasizing its unusual presentation and treatment.

## Key findings

- Disseminated coccidioidomycosis was diagnosed via lymph node biopsy and confirmed with C. immitis antibody tests.
- Treatment with antifungals improved imaging and antibody titers, but adalimumab was discontinued.
- The case underscores the risk of fungal dissemination with anti-TNF-α therapies.

## Abstract

Musculoskeletal coccidioidomycosis is a rare disseminated fungal infection caused by either Coccidioides immitis or Coccidioides posadasii endemic to the southwestern United States and northwestern Mexico, as well as Guatemala, Brazil, and other locations in Central and South America. Symptomatic primary infection of coccidioidomycosis can present as pneumonia with influenza-like symptoms, but the majority of cases remain asymptomatic. When dissemination occurs, the most common extrapulmonary sites include the skin, lymph nodes, musculoskeletal system, and meninges. We present a case of a 53-year-old female with a history of breast cancer and ankylosing spondylitis treated with adalimumab who presented with disseminated coccidioidomycosis. On presentation, she reported subcutaneous nodules on the right forearm and elbow. Radiologic evaluation utilizing magnetic resonance imaging (MRI) and positron emission tomography (PET) scan revealed multiple subcutaneous and bony enhancing lesions in her right forearm, lumbar spine, iliac wing, and axillary lymphadenopathy. Given the patient's history of breast cancer, there was concern for metastatic disease. Axillary lymph node biopsies were negative for malignancy, but immunoreactive for C. immitis with a positive Grocott methenamine silver (GMS) stain and a C. immitis antibody panel confirmed the diagnosis of disseminated coccidioidomycosis. Treatment with fluconazole was initiated along with discontinuation of adalimumab. Fluconazole was transitioned to itraconazole due to adverse effects. Treatment was successful as evidenced by improved PET imaging and downtrending C. immitis antibody titers. This case highlights the concerning potential for dissemination of endemic mycoses with anti-tumor necrosis factor-α (TNF-α) therapies and the unique ways in which they can present. Further investigation is needed to determine the long-term implications of the disease and the role that immunosuppressive medications play in disease susceptibility.