OBJECTIVETo observe the characteristics of tongue proper and tongue coating in patients with severe acute respiratory syndrome (SARS) and to explore the relationship between tongue picture and state of illness.

METHODSTongue picture was taken by digital camera and colors (red, green and blue) of tongue proper and coating were analyzed quantitatively with image processing software.

RESULTSIn the 69 patients of acute stage, the color of tongue proper was mostly light red (51 patients, 73.9%), with significant difference in comparing with other colors (P < 0.01). The color of tongue coating was mostly thin yellow (32 patients, 46.4%), and thin white was the second (29 patients, 42.0%). There was swollen tongue body in 5 patients (7.2%), teeth print on tongue margin in 12 cases (17.4%). In the 155 patients of recovery stage, the color of tongue proper was mostly dark pale (72 patients, 46.5%), the second light red (68 patients, 43.9%), color of tongue coating was mostly thin white (80 patients, 51.6%), which was significantly higher than other colors (P < 0.01), the second was yellow in tongue root region (31 patients, 20.0%). Swollen tongue body was found in 23 patients (14.8%) and teeth print on margin was found in 19 patients (12.3%). Most patients of ordinary state had light red tongue proper and thin white coating, patients of severe state mostly had dark pale tongue proper and yellow coating in root region, and the critical patients were mostly with dark pale proper and thick yellow coating. Patients with affected lung > or = 3 lobules mostly had pale dark proper and yellow coating on root, but those with involved lung < 3 lobules mostly had light red proper and thin white coating.

CONCLUSIONThe colors detected quantitatively by the method described above could comparatively reflect the difference of tongue proper and coating sensitively. Tongue picture is one of the objective evidence for judging state of illness and Syndrome Differentiation based on treatment in SARS patients.