{"uid":"cap_AvzqSJcOOxn1k3AZnjmri","slug":"caspar-criteria-calculator-for-psoriatic-arthritis-172283ad","name":"CASPAR Criteria Calculator for Psoriatic Arthritis","description":"Taylor 2006 CASPAR classification criteria for psoriatic arthritis. Required: inflammatory_articular_disease true (joint, spine, or enthesis). Score: current psoriasis 2; personal history 1 only if current is false; family history 1 only if current and personal are false; nail dystrophy 1; RF-negative 1; dactylitis (current or history) 1; juxtaarticular new bone 1. Classified iff score ≥3 (max 8). Not a diagnosis. Not Moll and Wright. magent does not examine skin or read films.","url":"https://api.magentlab.com/api/calc/caspar","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["inflammatory_articular_disease","current_psoriasis","personal_history_psoriasis","family_history_psoriasis","nail_dystrophy","rheumatoid_factor_negative","dactylitis","juxtaarticular_new_bone"],"properties":{"dactylitis":{"type":"boolean","description":"Current swelling of an entire digit, or a history of dactylitis recorded by a rheumatologist, as assigned by the caller (Taylor 2006). true scores 1. magent does not examine digits."},"nail_dystrophy":{"type":"boolean","description":"Typical psoriatic nail dystrophy including onycholysis, pitting, and hyperkeratosis on current examination, as assigned by the caller (Taylor 2006). true scores 1. magent does not examine nails."},"current_psoriasis":{"type":"boolean","description":"Current psoriasis as assigned by the caller (Taylor 2006): psoriatic skin or scalp disease present today as judged by a rheumatologist or dermatologist. true scores 2. When true, personal_history_psoriasis and family_history_psoriasis do not add. magent does not examine skin."},"juxtaarticular_new_bone":{"type":"boolean","description":"Radiographic ill-defined ossification near joint margins, excluding osteophyte formation, on plain radiographs of the hand or foot, as assigned by the caller (Taylor 2006). true scores 1. magent does not read films."},"family_history_psoriasis":{"type":"boolean","description":"Family history of psoriasis as assigned by the caller (Taylor 2006): first- or second-degree relative according to patient report. true scores 1 only if current_psoriasis is false and personal_history_psoriasis is false. magent does not take a pedigree."},"personal_history_psoriasis":{"type":"boolean","description":"Personal history of psoriasis as assigned by the caller (Taylor 2006): a history that may be obtained from the patient, family physician, dermatologist, rheumatologist, or other qualified health care provider. true scores 1 only if current_psoriasis is false. magent does not examine skin."},"rheumatoid_factor_negative":{"type":"boolean","description":"Negative rheumatoid factor by any method except latex, preferably ELISA or nephelometry according to the local laboratory reference range, as assigned by the caller (Taylor 2006). true scores 1. magent does not assay rheumatoid factor."},"inflammatory_articular_disease":{"type":"boolean","description":"Must be true. Taylor 2006 CASPAR entry: established inflammatory articular disease of joint, spine, or enthesis as assigned by the caller. false is invalid and is not classified=false. magent does not examine joints."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_wZNQj9NW-sLBMeHyuhUpe","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the Taylor 2006 CASPAR score for psoriatic arthritis classification and returns whether the criteria are met (score ≥ 3).","exampleAgentPrompt":"Score this patient for psoriatic arthritis using CASPAR criteria: they have confirmed inflammatory articular disease, current psoriasis is present, nail dystrophy is present, rheumatoid factor is negative, dactylitis history is positive, and no juxtaarticular new bone on imaging — no personal or family history flags needed since current psoriasis is true.","exampleUseCases":[{"title":"Rheumatology clinic PsA classification","prompt":"I have a patient with inflammatory joint disease: current psoriasis is true, nail dystrophy is present, RF is negative, no dactylitis, and no juxtaarticular new bone. Can you run the CASPAR criteria and tell me if they classify for psoriatic arthritis?"},{"title":"Research cohort eligibility screening","prompt":"For a clinical trial, I need to classify whether patients meet CASPAR criteria. This subject has inflammatory articular disease, no current psoriasis but a personal history of psoriasis, RF is negative, dactylitis history is positive, nail dystrophy is true, and no juxtaarticular new bone — please calculate their CASPAR score."},{"title":"EHR-integrated decision support check","prompt":"Check CASPAR classification for a patient: inflammatory articular disease confirmed, current psoriasis false, personal history of psoriasis false, family history of psoriasis true, nail dystrophy false, rheumatoid factor negative true, dactylitis current or history false, juxtaarticular new bone false."}],"resultDescription":"Returns the total CASPAR score (integer, 0–8), whether the patient meets classification (score ≥ 3 with inflammatory articular disease confirmed), and optionally per-criterion point contributions. Does not provide a clinical diagnosis.","failureModes":["Missing required inflammatory_articular_disease parameter returns validation error","Invalid boolean values for any parameter return schema error","inflammatory_articular_disease false short-circuits classification regardless of score","Score may be misleading if caller-assigned clinical flags are inaccurate — garbage-in, garbage-out","Network or payment authorization failure returns 402 or connectivity error"],"whenToPreferThis":"Use this endpoint when you need a programmatic, auditable computation of the Taylor 2006 CASPAR score for psoriatic arthritis classification in a rheumatology or clinical research workflow. Prefer it over manual scoring tables when integrating into EHR pipelines, research eligibility screens, or agentic clinical decision support. Note: this endpoint computes criteria only — it does not examine patients, read imaging, or provide diagnoses. It should not be confused with the older Moll and Wright criteria.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:53:41.727Z","isFirstParty":false}