Systemic lupus erythematosus associated with antibiotics-induced interstitial pneumonitis: a case report

Abstract

[Summary]A case of systemic lupus erythematosus (SLE) with interstitial pneumonitis developing concurrently with antibiotics administration is reported.A 50-year-old woman was administered amoxicillin by a practitioner because of fever and arthralgia, but she remained febrile. On admission to our hospital, initial studies revealed leukopenia, positive LE cells, positive antinuclear antibody, high titer of anti-DNA antibodies, and hypocomplementemia. Chest X-ray films showed minimal interstitial changes. The diagnosis of SLE was made and prednisolone, 60 mg daily, was started. Her symptoms and laboratory findings, including chest X-ray abnormalities improved, and the dose of prednisolone was tapered. When prednisolone was tapered to 35 mg daily, she was given cephalexin for sinusitis. A few days following the antibiotics therapy, fever, cough and dyspnea gradually appeared, and diffuse interstitial changes developed on chest X-ray films. Prednisolone was tapered to 30 mg, cephalexin was discontinued, and ampicillin, followed by cefinenoxime were administered. However, her clinical symptoms became progressively worse associated with densely infiltrative interstitial changes in both lungs. Combination therapy with INH and trimethoprim-sulfamethoxazole was added. About one week after the beginning of cefmenoxime, eosinophilia and high level of serum LDH appeared. Drug-induced pneumonitis was suspected and cefmenoxime was discontinued. Consequently, clinical symptoms , laboratory data, and interstitial pneumonitis on chest films improved promptly. Histopathologic examinations of a transbronchial biopsy specimen discolsed alveolar septal thickening with fibrosis, and perivascular lymphocytic infiltration, compatible with the diagnosis of interstitial