Diagnosis
Sarcoidosis is diagnosed on the basis of clinical and radiological suspicion, combined with biopsy evidence of non-caseating granulomata, in the absence of any other cause of granulomatous disorders (1).
The Kveim reaction is important as a clinical observation in making a diagnosis of sarcoidosis (3, 4), however its use has fallen out of favour over the years. Imaging techniques routinely employed include CT (HRCT is particularly useful in chest sarcoid diagnosis) and MRI (with gadolinium contrast) (6, 7). Biopsy typically yields multiple epithelioid cell granulomata made from mononuclear cells, with variable degrees of necrosis, leucocyte infiltration and hyaline fibrosis (4). Supporting evidence can include a high CD4/CD8 T lymphocyte ratio on bronchoalveolar lavage (1, 2).
Blood tests can provide supporting evidence for the diagnosis of sarcoidosis. Serum Angiotensin-converting enzyme (ACE) levels are often raised in sarcoidosis, however the nonspecific and insensitive nature of this rise relegates its use to monitoring the course of the disease (8). Hypercalcaemia may also be seen (1) and other acute phase reactants, such as ESR, may also be raised.