How is sarcoidosis diagnosed?

Sarcoidosis is diagnosed based on a combination of the patient's clinical symptoms, imaging findings, laboratory tests, and sometimes a biopsy. Here's an outline of the diagnostic process:

1. Medical History and Symptoms:

- The doctor takes a detailed medical history, noting symptoms such as shortness of breath, cough, fatigue, joint pain, skin rash, or eye problems.

2. Physical Examination:

- The doctor performs a physical examination to assess general health, listen to the lungs, feel for swollen lymph nodes, and check for any skin lesions.

3. Imaging Tests:

- Chest X-ray: Can reveal the presence of lung involvement, such as inflammation or scarring.

- Computed tomography (CT) scan: Provides more detailed images of the lungs and other organs to detect abnormalities.

- Positron emission tomography (PET) scan: Can identify areas of increased metabolic activity, which may indicate sarcoidosis lesions.

4. Laboratory Tests:

- Blood tests: These may include:

- Angiotensin-converting enzyme (ACE) level: Elevated ACE levels can be associated with sarcoidosis.

- Complete blood count (CBC) and erythrocyte sedimentation rate (ESR): May show signs of inflammation and anemia.

- Liver function tests: Can detect liver involvement.

- Renal function tests: To evaluate kidney function.

5. Biopsy:

- If other tests are inconclusive or to confirm the diagnosis, a biopsy may be necessary. During a biopsy, a small tissue sample is collected from the affected area (such as the lungs, lymph nodes, or skin) and examined under a microscope.

The combination of these diagnostic techniques helps medical professionals establish a diagnosis of sarcoidosis and determine the extent and severity of the condition. Sarcoidosis can sometimes be difficult to diagnose as it can mimic other conditions, so a thorough evaluation is essential.