The American College of Rheumatology 1990 criteria for the classification of churg‐strauss syndrome (allergic granulomatosis and angiitis)

TLDR

The study discusses how the traditional criteria for Churg‑Strauss syndrome compare with a classification tree approach and with prior research. The authors derived CSS classification criteria by comparing 20 CSS patients to 787 vasculitis controls, selecting six clinical features for a traditional set and constructing a simpler tree using asthma, eosinophilia > 10 %, and allergy history. Using four or more of the six criteria achieved 85 % sensitivity and 99.7 % specificity, while the three‑criterion tree reached 95 % sensitivity and 99.2 % specificity.

Abstract

Abstract Criteria for the classification of Churg‐Strauss syndrome (CSS) were developed by comparing 20 patients who had this diagnosis with 787 control patients with other forms of vasculitis. For the traditional format classification , 6 criteria were selected: asthma, eosinophilia >10% on differential white blood cell count, mononeuropathy (including multiplex) or polyneuropathy, non‐fixed pulmonary infiltrates on roentgenography, paranasal sinus abnormality, and biopsy containing a blood vessel with extravascular eosinophils. The presence of 4 or more of these 6 criteria yielded a sensitivity of 85% and a specificity of 99.7%. A classification tree was also constructed with 3 selected criteria: asthma, eosinophilia >10% on differential white blood cell count, and history of documented allergy other than asthma or drug sensitivity. If a subject has eosinophilia and a documented history of either asthma or allergy, then that subject is classified as having CSS. For the tree classification, the sensitivity was 95% and the specificity was 99.2%. Advantages of the traditional format compared with the classification tree format, when applied to patients with systemic vasculitis, and their comparison with earlier work on CSS are discussed.