Erguss

Erguss is a German medical term that describes the abnormal accumulation of fluid within a normally potential space, most commonly in a joint but also in other body cavities. In orthopedics the term is often used to refer to a Gelenkerguss (joint effusion), while in pulmonary or cardiothoracic contexts it can denote Pleuraerguss (pleural effusion) or Perikarderguss (pericardial effusion).

In joints, an effusion presents as swelling around the joint, reduced range of motion, and sometimes warmth or pain. The underlying causes are diverse, including inflammatory or degenerative joint diseases (such as osteoarthritis or rheumatoid arthritis), injury, infection (septic arthritis), crystal arthritis (gout or pseudogout), or neoplasia. In non-joint spaces effusions can cause respiratory symptoms (pleural effusion) or cardiac symptoms (pericardial effusion), depending on the location.

Diagnosis relies on a combination of history, physical examination, and targeted testing. Imaging, particularly ultrasound, is commonly used to confirm fluid accumulation and to guide aspiration. Additional studies include radiographs or MRI to assess structural causes. Fluid obtained by aspiration is analyzed for appearance, cell count, Gram stain and culture, crystal analysis, glucose, and protein levels to distinguish inflammatory, infectious, or malignant processes.

Treatment focuses on addressing the underlying cause and relieving symptoms. Fluid aspiration (drainage) can reduce pressure and pain. Depending on the diagnosis, options include anti-inflammatory or disease-modifying medications, antibiotics for infection, urate-lowering therapy for gout, diuretics for systemic causes, or surgical interventions in refractory cases.

Prognosis varies with the etiology and response to treatment; recurrent effusions may require ongoing management or procedural interventions.