In patients receiving anti–tumor necrosis factor (TNF)-α agents, a miliary pattern on chest imaging is often attributed to tuberculosis. However, fungal infections (histoplasmosis, blastomycosis, and coccidioidomycosis) and metastatic pulmonary disease should also be considered1,2.
A 40-year-old woman, diagnosed with ankylosing spondylitis, was in remission with adalimumab. She presented with a 3-week history of fever, night sweats, dyspnea, and dry cough. She reported exposure to demolition dust from a building adjacent to her workplace. On admission, she was normotensive and tachycardic, and oxygen saturation was 96% with supplemental oxygen (2 l/min). Breath sounds were decreased bilaterally. Chest radiograph and high-resolution computed tomography showed widespread miliary nodules throughout both lungs (Figure 1). Three sputum acid-fast bacillus (AFB) smears were negative. On the bronchoalveolar lavage sample, AFB stain, AFB culture, PCR for Mycobacterium tuberculosis complex were all negative, while fungal culture was positive for Histoplasma capsulatum. Transbronchial biopsy identified non-caseating granulomas (Figure 2A) and small ovoid or pear-shaped yeast with narrow-based budding consistent with H. capsulatum (Figure 2B). Urine Histoplasma galactomannan antigen was positive. Amphotericin-B was administered for 2 weeks followed by 12 months of oral itraconazole, with marked clinical improvement after therapy.
Histoplasmosis is the most frequent invasive fungal infection complicating anti-TNF-α therapy3; however, miliary histoplasmosis is a rare clinical presentation that mimics miliary tuberculosis, and diagnostic delays may lead to increased mortality3. Anti-TNF-α therapy discontinuation is recommended and antifungal treatment must be given for at least 12 months. Resumption of anti-TNF-α appears safe if antifungal therapy is administered for 12 months4.
Footnotes
The Hospital Universitario de San Vicente Fundación Research Ethics Committee approved the publication of this report (Act Nº 26-2019).
The patient gave written informed consent to publish the material.
REFERENCES
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