1. Complete Blood Count (CBC)
A complete blood count is a test that measures the number of eosinophils present in the blood. High levels of eosinophils may indicate severe eosinophilic asthma. During this test, a small sample of blood is drawn from a vein in your arm. The blood sample is then sent to a laboratory for analysis. If the eosinophil count is high, it suggests ongoing inflammation in the airways, which is a characteristic feature of severe eosinophilic asthma.
2. Fractional Exhaled Nitric Oxide (FeNO) Test
The fractional exhaled nitric oxide (FeNO) test measures the amount of nitric oxide gas in your breath. Nitric oxide is an inflammatory marker, and high levels of it can indicate airway inflammation, which is commonly seen in severe eosinophilic asthma. During the FeNO test, you will be asked to exhale forcefully into a small handheld device. The device analyzes the nitric oxide level in your breath and provides a measurement.
3. Pulmonary Function Tests (PFTs)
Pulmonary function tests, also known as PFTs, are a series of breathing tests that measure how well your lungs are functioning. Spirometry is one of the most common PFTs used to diagnose and monitor severe eosinophilic asthma. It measures the amount of air you can exhale forcefully and how quickly you can do it. Other PFTs, such as lung volume measurement and diffusion capacity tests, may also be performed to assess lung function and identify any abnormalities.
4. Allergy Testing
Allergy testing may be conducted to identify specific allergens that can trigger or worsen severe eosinophilic asthma symptoms. Skin prick tests and blood tests, such as specific IgE tests, can help determine if you have allergic sensitivities to common allergens like pollen, dust mites, mold, or pet dander. These tests involve exposing your skin or blood sample to small amounts of allergens and observing the reactions. Identifying and avoiding allergens can be an essential part of managing severe eosinophilic asthma.