Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis Manifesting Solely as Bilateral Toe Cyanosis: Case Report
Bibliographic record
Abstract
Introduction: Blue toe syndrome (BTS) manifests as a sudden onset of blue/violaceous discoloration on the toe that is often associated with pain. The etiology of this condition is multifactorial, but it is distinguished by its occurrence in the absence of trauma or generalized cyanosis. The differential diagnosis of BTS can include factors such as vascular obstruction, autoimmune conditions, hyperviscosity syndromes, infections, drug-induced occurrences, and vasospasm. The authors describe a case of a 71-year-old female who presented with a 2-year history of bilateral toe cyanosis and was found to have positive c-anti-neutrophil cytoplasmic antibody (ANCA) with high titer proteinase 3 (PR3; 735 mean fluorescence unit), Type III cryoglobulinemia, and positive cryofibrinogen. She had no other symptoms associated with ANCA vasculitis. Further rheumatologic workup was unremarkable, including investigations for atheroembolic disease and infections. The patient was prescribed azathioprine with near complete resolution of symptoms within 1 year. Methods/Results: To further understand this condition, the authors performed a literature review of PubMed/Scopus/Medline using the following combination of keywords: “vasculitis” AND (“Blue” OR “purple” OR “cyanosis” OR “necrotic” AND “toe”). This search yielded only one other case of this manifestation. Conclusion: In this report, the authors identify, to the best of their knowledge, the first documented case of PR3-ANCA vasculitis presenting with BTS as the sole and primary manifestation.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".