The diagnosis of undifferentiated connective tissue disease is based on the presence of arthritis, Raynaud’s phenomenon, interstitial lung disease, myositis, and more than one rheumatologic symptom, accompanied by at least one high-titer autoantibody, but does not meet the specific diagnostic criteria for any of the rheumatologic diseases.
The pathogenesis of undifferentiated connective tissue disease is still unclear, usually insidious onset, patients with mild clinical symptoms, may manifest as fatigue, low fever, lymph node swelling, skin lesions, etc. Currently, the diagnosis of undifferentiated connective tissue disease mainly relies on the patient’s symptoms, observing the patient’s presence of arthritis, Raynaud’s phenomenon, interstitial lung disease, myositis and other rheumatologic diseases, such as more than one symptom or sign.
Patients with more than one of these symptoms or signs who do not meet any of the specific diagnostic criteria for rheumatoid arthritis or systemic lupus erythematosus should be considered to have an undifferentiated connective tissue disease, but also need to be combined with relevant autoantibodies such as antinuclear antibody profiles, anti-SSA antibodies, anti-SSB antibodies, anti-RNP antibodies and so on.
The diagnosis of undifferentiated connective tissue disease should be made by a professional physician, and it is recommended that patients with suspected undifferentiated connective tissue disease go to the rheumatology and immunology department of a regular hospital for consultation.