Getting an Accurate Diagnosis and Essential Testing

Diagnosing relapsing polychondritis (RP) is often a process of “connecting the dots” rather than finding a single “smoking gun.” Because there is no single blood test that can definitively prove you have RP, doctors must synthesize your physical symptoms, medical history, and a suite of specialized tests to confirm the diagnosis and rule out mimics ^[1][2].

The Role of Clinical Criteria

To help guide this process, doctors often use established sets of rules called clinical criteria, such as the McAdam, Damiani-Levine, or Michet criteria ^[3]. These classification frameworks look for combinations of signs, like inflammation in both ears, joint pain, or eye redness.

However, these rules are aids for classification and research, not definitive diagnostic laws. Research has shown that they can miss evolving or limited disease. In one study of 87 patients clinically diagnosed with RP, 65.5% did not meet the traditional criteria because their symptoms were “limited” or atypical at the time ^[4]. If you don’t meet every checkmark on the list yet, it does not necessarily mean you don’t have the condition; a specialist may rely on follow-up and clinical judgment rather than a single checklist ^[1][5].

Evaluating Your Airway and Heart

Because RP can affect vital internal organs without initially causing obvious symptoms, your specialist will consider whether you need baseline screening of your respiratory and cardiovascular systems. The choice among tests is individualized, depending on your symptoms, prior results, radiation concerns, and local expertise.

• Airway Screening: Tests like Pulmonary Function Tests (PFTs) provide a “functional map” of your breathing ^[6]. A Chest CT may be used, and a Dynamic Expiratory CT (taking images while forcefully breathing out) is one useful way to see tracheobronchomalacia—where the airway cartilage collapses during exhalation ^[7][8][9]. However, this involves radiation, so the protocol is tailored to you.
• Heart and Vessel Screening: RP can affect the aorta (the body’s largest artery) and the heart valves. Baseline screening often includes an Echocardiogram and ECG ^[10][11]. Because an echocardiogram visualizes the valves but only portions of the proximal aorta, a CT or MRI may be selected when clinically indicated to assess the entire structure ^[12].

Advanced Tools: Biopsy and PET/CT

• Cartilage Biopsy: Taking a small sample of cartilage can sometimes provide supportive evidence, but it is not always necessary if your clinical symptoms are clear, and it is not a definitive confirmatory test ^[5]. Doctors may use it if they need to rule out “mimics” like infection, but the procedure can damage already fragile cartilage.
• FDG-PET/CT: This scan uses a radioactive sugar tracer to find “hot spots” of inflammation throughout the body. While it can map disease activity, it lacks specificity (it can also reflect infection) and is an adjunct used selectively when it will change management, not a standard test for everyone ^[13][14].

A Note on Bronchoscopy

A bronchoscopy (using a camera to look inside the lungs) is sometimes needed for a direct look at the airway. However, in suspected RP patients, this procedure carries specific risks, such as triggering an airway spasm or swelling ^[7]. It should only be performed by specialists—typically a “difficult airway” team—who have a clear rescue plan in place for your breathing during the procedure ^[15][16].