Pinpointing the number of people with lupus is no easy task.
Research and awareness about lupus are both limited. According to the Lupus Foundation of America, 72% of Americans aged 18-34 have either never heard of lupus or know little or nothing beyond the name. This is worrisome as that age demographic is at the highest risk for the disease. Failure to understand the symptoms of the disease may lead to lower rates of diagnosis — and more untreated people with the disease.
The Lupus Foundation of America estimates that 1.5 million Americans have some form of lupus.
At that prevalence, there would be 1 case of lupus for every 216 people in the United States. This estimate includes systemic lupus erythematosus, cutaneous lupus erythematosus, and drug-induced lupus erythematosus. It appears that the LFA is attempting to evaluate the actual prevalence of these diseases and is not simply considering the current diagnosis rate.
The National Institutes of Health estimated that 240,000 Americans are diagnosed with lupus.
That would be 1 case of lupus for every 1,350 people — nearly 7 times less common than the LFA estimate. Of note, the NIH number only examined SLE and people that had received a diagnosis. It is entirely possible that people are either unaware of their symptoms and do not pursue a diagnosis, or are struggling to receive a lupus diagnosis.
A study published in the journal Arthritis & Rheumatology examined lupus prevalence among adults in California and Pennsylvania.
In California, the data revealed 1 case of lupus (SLE) for every 929 adults. And, in Pennsylvania, 1 case of lupus (SLE) for every 668 adults. Based on the typical age of onset of symptoms, the authors of the study suggest that adding children to the estimates would lower the prevalence by approximately 25%. These findings are in line with the NIH number regarding the number of people that have received a diagnosis and are being treated for care. And, this likely means that many people are living with undiagnosed lupus — though truly identifying that number may be difficult to discover.