No Market, No Attention: Pernicious Anemia and the Cost of Invisibility
I. A Patient’s Half-Century of Missed Diagnosis
Starting at age 17 — around 1974 — a woman found out repeatedly that she was anemic, not through medical care but because blood banks turned her away. More than half the time she tried to donate blood, the screening test flagged her hemoglobin as too low. When she mentioned this to a physician, the response was a casual suggestion to take iron tablets. No one ordered a workup to determine why the anemia kept recurring. No one tracked the finding across visits. The encounters closed, and the question closed with them.
This pattern held for decades. Laboratory work ordered for fatigue returned mostly-normal findings that generated no investigation. Fatigue itself — the kind that makes sustained effort feel like moving through resistance — was so constant that it registered as normal. When you have never experienced adequate energy, there is no baseline against which to measure the deficit. The symptoms accumulated without a name.
In 2018, she asked for a specific test: intrinsic factor antibody. The result came back positive. A positive intrinsic factor antibody is, in clinical terms, essentially diagnostic for pernicious anemia — the test has a false positive rate below five percent, making it among the most specific results in autoimmune medicine. The provider initiated B12 injections. Once monthly. No loading dose. No protocol adjustment for neurological involvement, which clinical guidelines address specifically. No explanation of what pernicious anemia meant, what damage it caused, or why consistent treatment mattered. The patient, given no reason to treat the injections as urgent, sometimes missed months. Nothing in her experience with clinicians suggested she should do otherwise.
During this same period, she had two ischemic strokes (2016 and 2018). After the first stroke, a cardiologist performed a transesophageal echocardiogram, which found no embolic source. After the second, evaluation at Barrow Neurological Institute in Phoenix found no identifiable cause for either event. The emergency workup on July 12-conducted three months after a confirmed PA diagnosis-included cardiac markers, coagulation studies, and a comprehensive metabolic panel. It did not include B12 or homocysteine. In a patient with a confirmed autoimmune B12 deficiency presenting with a second cryptogenic stroke, that gap represents a failure of clinical integration, independent of what those results would have shown.
In the spring of 2024, she developed urticaria and stopped all supplements, including B12 injections, to identify a possible cause. Within approximately two months, her balance deteriorated to the point where she could not walk two steps. She was hospitalized for stroke assessment. The hospital discharged her with a diagnosis of benign paroxysmal positional vertigo. She was referred to physical therapy. The physical therapist, after several sessions, noted that the presentation did not fit BPPV and appeared neurological in origin. The patient, who by then had spent years educating herself about B12 metabolism, recognized the connection. She resumed injections. The balance impairment resolved.
She is now in her late sixties. To maintain proprioception and basic balance, she requires an injection every two days. Much of the neurological damage that accumulated across the decades before adequate treatment began has not reversed.