Late-Onset Systemic Lupus Erythematosus Presenting with Lupus Pneumonitis

Authors

Christopher Manzella, Rebecca Kreston MD MSPH, Stefan Tchernodrinski MD MS Department of Medicine, University of Illinois at Chicago, Chicago, IL

Introduction

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with significant clinical heterogeneity upon presentation. This poses a diagnostic challenge for physicians, especially when patients present later in life when diseases with overlapping features, such as malignancy, increase in prevalence.

Case Presentation

A 55-year-old African-American man with hypertension presented to the emergency room with fatigue, night sweats, shortness of breath, and a productive cough for the past 6 months. Several courses of antibiotics for presumed pneumonia did not result in improvement. He had also recently experienced acute onset of pain of his proximal right thigh as well as right-sided pleuritic chest pain associated with two episodes of hemoptysis which prompted him to visit the emergency room. He had no history of tobacco use or recent travel. On examination, the patient was afebrile and hemodynamically stable. Crackles were heard in bilateral lower lung fields on exam and there was tenderness to palpation of his right proximal thigh with intact active and passive range of motion. There were no notable skin findings or alopecia. Labs revealed hyponatremia, pancytopenia, and a protein gap. CT chest demonstrated bilateral pleural effusions, mediastinal adenopathy, and alveolar infiltrates at both lung bases. An x-ray of the right femur showed an insufficiency fracture of the femoral neck. The patient initially underwent a malignancy work-up, however an x-ray bone survey and serologic markers of malignancy including CEA, AFP, CA 19-9, and SPEP/UPEP were negative. Bronchoscopy and biopsy were consistent with an organizing pneumonia, however serial sputum and bronchoalveolar lavage with AFB stains, cultures, and fungal serology were all negative. Patient was then evaluated for possible rheumatologic disease which yielded positive ANA titers. Additional serology including ds-DNA, anti-histone, anti-Ro, anti-Smith, anti-RNP, anti-SSB, and anti-chromatin antibodies were pan-positive with high titers. Both C3 and C4 levels were also decreased. Based upon these findings, a diagnosis of spontaneous versus drug-induced SLE was made and high-dose intravenous steroid therapy was initiated. Hydrochlorothiazide was discontinued due to concern for drug-induced SLE based upon positive anti-histone serology. Patient was discharged on a prednisone taper with improvement in his subjective symptoms and was lost to follow-up.

Discussion

This case demonstrates an atypical presentation of SLE in an older male who presented initially with clinical features concerning for a malignancy or infectious process. The insufficiency fracture of the femoral neck, while not typical for SLE, steered the initial investigation toward a malignancy work-up. The lack of skin findings with prominence of pulmonary findings are both features that are uncommon for an initial presentation of SLE. Due to the age of the patient and positive anti-histone and anti-Ro antibodies, it is very possible that this patient had drug-induced SLE with hydrochlorothiazide being the causative agent. Maintaining a high suspicion for rheumatologic diseases including SLE is critical when a patient presents with systemic symptoms in the absence of an underlying malignancy.

Want to have your abstract featured here? ACP holds a National Abstracts Competition as part of the ACP Internal Medicine Meeting every year. Find out more at ACP Online.

Back to the March 2021 issue of ACP IMpact