Diagnosis of Lofgren's Syndrome and the Role of Ultrasound

We report the case of a 32-year-old woman presenting to the emergency department with ankle edema and arthralgia. Only later in the follow-up period, she developed erythema nodosum. The study revealed bilateral hilar and mediastinal lymphadenopathy and biopsy demonstrated non-caseating granulomas consistent with a diagnosis of Lofgren's syndrome. Patients often do not present with all signs and symptoms, which delays the correct diagnosis. This case reinforces the need to use diagnostic methods, particularly non-invasive ones, such as ultrasound (US), in such cases. US of the lower extremity swelling could have helped the diagnosis, even without demonstrating effusion.