Alaric Moore

We don’t actually know how many people have lupus,

…and I am confident this is harming patients.

Since being diagnosed, lupus has become one of my special interests (I’m autistic, so when I say that, I mean it in the full-blown “I have read every paper I can find and have built many SARD specific tools” sense). And something keeps happening: the more I learn, the more lupus I find.

In my own family: three generations of women on my father’s side, all in central Oklahoma, all with lupus-spectrum SARDs or lupus itself, including my father. Among coworkers’ family members or themselves. Among friends and friends of friends. Some of my clinicians. Everywhere I look, lupus, or some flavor of it (MCTD, DM, Incomplete lupus, cutaneous, UCTD, RA… you get the drift) seems to exist in one way or another.

For a while I wondered if this was just the Baader-Meinhof effect, you buy a red car and suddenly every car on the road is red. But then I started reading how SLE prevalence is actually measured in this country, and I realized: it might not be that I’m suddenly noticing lupus everywhere. It might be that lupus actually is everywhere, and we’ve just never properly counted.

I’m writing this because of a recent thread on r/lupus about the racial prevalence of lupus — prompted by an interview between two people I’d never heard of who said some incorrect things about lupus prevalence. There were some good points made in the thread, but I think the conversation was missing a critical piece:

The numbers we’re all arguing about are far less solid than most people realize, and that uncertainty isn’t just academic; it’s shaping how our doctors and society views us, and ultimately shapes health outcomes down the line.

Here’s the situation:

SLE is not a nationally reportable disease. Unlike cancer, TB, or HIV, no one is required to report new lupus cases to any central database. There is no national lupus count. What we have instead are estimates, built from a small number of regional registries.

The number most commonly cited in research, about 204,000 Americans with SLE, comes from a 2021 meta-analysis (Izmirly et al., Arthritis & Rheumatology) that pooled data from five CDC-funded registries. Those registries covered portions of Georgia, Michigan, California, New York, and the Indian Health Service. The data was collected between 2002 and 2009, then extrapolated to the 2018 census. The authors themselves describe this as likely representing a lower bound.

The older “1.5 million” number the Lupus Foundation uses? That comes from a 1994 telephone marketing survey.

Neither of these is a count. They’re estimates built on estimates.

And when a broader method is used — a nationally representative survey (MEPS, 2016–2018) that paired self-reported diagnosis with a rheumatologist visit or lupus medication — adult prevalence comes out around 195 per 100,000, or roughly 490,000 adults. The two figures aren’t strictly comparable: the registries count all ages and under-ascertain, while the survey counts adults and can over-report. But every wider-net method lands well above the registry floor.

The registries used ACR classification criteria to define cases. These criteria were designed for research classification, not clinical diagnosis. The Lupus Foundation itself has noted that at one major academic medical center, only half of patients actively receiving lupus treatment met those criteria at that time, or ever. So the registries were structurally guaranteed to miss roughly half the population being treated.

The registries also excluded cutaneous lupus, incomplete lupus, and drug-induced lupus entirely. And they covered parts of five states, not the country.

Why this matters for you, personally:

When a doctor “knows” that lupus is rare and primarily affects young Black women, that shapes how they evaluate every patient who walks in. A white woman with fatigue and joint pain gets worked up differently than a Black woman with the same symptoms. An older patient gets told it’s “probably not lupus.” A man doesn’t even get considered. And then we can’t forget about the general issue with many, not all, clinicians not trusting the reporting of pain and vague symptoms from women of any race or economic background.

But we can’t actually say with confidence how lupus prevalence breaks down by race or geographic region, because the counting methodology itself has racial blind spots. The IHS registry in Oklahoma, covering Native American patients, validated fewer than 10% of potential cases, compared to 35-40% in the registry’s other regions, Alaska and Phoenix (Ferucci et al. 2014, Arthritis & Rheumatology).

Was that because Native Americans in Oklahoma don’t get lupus? No. It was because IHS Oklahoma had limited rheumatology infrastructure at the time the data was collected. That wouldn’t exist until 2011. They conducted their census in 2009.

We observe disparities in every study that’s been done. Black women consistently show higher rates, and by all accounts that demographic appears to have more aggressive disease. But we cannot say how much of the observed disparity is biology versus access, detection, and counting methodology, because the counting itself is incomplete.

The perception that lupus is rare is not a fact.

It’s an artifact of not conducting an accurate census. And that artifact has clinical consequences every time one of us sits in an exam room and gets told our symptoms are probably anxiety.

This may be contributing to the roughly 3-4 year average for diagnostic delay (and as long as 6 in some cohorts). Which then in turn leaves more time for organ damage accrual and missed opportunities for earlier interventions, which are often less costly and allow patients to remain working and stay off disability for longer periods.

I am not saying this is a doctor problem or a bureaucratic problem or a patient problem or a race or sex problem.

This is a simple numbers problem.

We need to start reporting cases of SLE (and other lupus-associated diseases) to a national registry. This will improve health outcomes, research funding, and save lives of those who are caught far beyond just joint aches and rashes.

What you can do

(and I’m not associated with any of these organizations, for the record):

If you have multiple family members with lupus or a lupus-spectrum condition, consider enrolling in the OMRF Lupus Family Registry and Repository. They’re specifically looking for families with two or more affected members. It’s one of the few efforts that’s actually trying to build a real genetic dataset. Contact: ADI-Requests@omrf.org or (405) 271-7221.

If you’re in the U.S., the Lupus Foundation’s RAY registry (lupus.org) is an online self-enrollment option, it takes about 45 minutes and you can save your progress.

And the next time a doctor tells you lupus is rare: it’s not rare, and if it is we can’t say so with confidence. It’s uncounted. The CDC says so themselves.

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