Raynaud’s phenomenon may signal the development of mixed connective tissue disease, as a study showed that it was the most common symptom in people who were later diagnosed with the condition.
The study, “Epidemiology of Mixed Connective Tissue Disease, 1985–2014: A Population-Based Study,” published in the journal Arthritis Care & Research also demonstrated that the rates of Raynaud’s increased even more once the connective tissue disease diagnosis was confirmed.
To get a better picture of how widespread the condition was, researchers at the Mayo Clinic in Minnesota looked through medical records of people living in Olmsted County, Minn., between 1985 and 2014.
The team found 50 people in the county with mixed connective tissue disease, defined as fulfilling at least one of four sets of diagnostic criteria. The majority had obtained a clinical diagnosis of the condition, while seven had been diagnosed with undifferentiated connective tissue disease.
Among the patients — who had a mean age of 48.1 years and were mostly (84%) women — 50% have had Raynaud’s phenomenon before receiving a connective tissue disease diagnosis. Together with joint pain, affecting 30%, and swollen hands, present in 16% of the group, Raynaud’s was the most common symptom signaling the development of the disease.
It took patients a median of 3.6 years to receive a diagnosis after the first symptoms appeared. After diagnosis, Raynaud’s became the second-most common symptom after joint pain, affecting 86% and 80%, respectively.
In addition, swollen hands, low numbers of white blood cells, and heartburn affected large proportions of the group.
Researchers also looked at how symptoms developed by examining data from each patient’s last follow-up visit. The analysis showed that many developed more scleroderma-like symptoms over time.
The condition of a small number of patients developed into other diseases; three were diagnosed with lupus and two with scleroderma. This corresponded to a 10-year rate of 8.5% transitions from mixed connective tissue disease to lupus, and 6.3% to scleroderma. Importantly, the study found that the death rate in these patients was no different from the general population.
The yearly rate of newly diagnosed mixed connective tissue disease cases was 1.9 per 100,000 individuals. Split among men and women, the rate was 0.7 per 100,000 in men and 3.1 per 100,000 in women.