Mixed and Undifferentiated Connective Tissue Disease

Autoimmune disorders frequently exhibit symptom overlap and are characterized by laboratory findings that may be unexpected to anyone outside the field of rheumatology. Specific connective tissue illnesses are defined by characteristic signs, symptoms, and autoantibodies. Certain patients have distinct symptoms, although their classification remains inconclusive. Furthermore, there are patients who satisfy the criteria for multiple distinct connective tissue diseases. Diagnosing and predicting the prognosis of these patients can provide challenges. The elucidation of the condition of each patient has the potential to enhance the quality of patient care.