Celiac Risk Score Calculator

This tool combines three categories of evidence into a single points-based risk-stratification score for celiac disease: classic and extra-intestinal symptoms (chronic diarrhea, bloating, unexplained weight loss, iron-deficiency anemia, and the pathognomonic dermatitis herpetiformis rash), serology (tTG-IgA result and EMA), and recognized risk factors (first-degree family history, type 1 diabetes, and other autoimmune disease). The percentage figure this tool reports is the score expressed as a percentage of the maximum possible points -- it is NOT a calibrated clinical probability. A published pre-test probability would need to be derived from a cohort study mapping symptom/serology combinations to actual diagnosis rates; this tool has no such calibration, so a result of, say, 50% does not mean a 50% chance of celiac disease -- treat it as "roughly half of this tool's maximum risk-stratification score," not as a population-level probability. tTG-IgA carries the heaviest weight because it is the best-performing single screening test in the literature, at roughly 93% sensitivity and 98% specificity, and dermatitis herpetiformis is weighted almost as heavily because a biopsy-confirmed case of that rash is itself considered essentially diagnostic. This calculator asks for tTG-IgA in two different ways -- a categorical result (negative/weak/strong) and a numeric multiple of the assay's upper limit of normal (ULN) -- because lab reports vary in which they provide.

These are two representations of the SAME antibody test, not two separate pieces of evidence, so the scoring takes whichever of the two contributes more points rather than adding both; entering both fields for the same lab result does not inflate the score. The tTG-IgA multiple of ULN stops earning additional points once it reaches 10x the upper limit of normal, because 10x ULN is itself the recognized cutoff (per ESPGHAN pediatric criteria, now often extended to adults) above which biopsy can reasonably be skipped if EMA also confirms positive. That no-biopsy pathway requires both criteria together; a very high tTG-IgA alone, without a positive EMA on a separate sample, does not by itself clear the bar this calculator applies. This is a screening aid, not a diagnostic tool -- it does not account for whether the patient was on a gluten-containing diet at the time of testing (a false-negative risk if not), and a formal diagnosis still generally requires biopsy confirmation outside the no-biopsy pathway.