Antistreptolysin O (ASO) titer is a blood test to measure antibodies against streptolysin O, a substance produced by group A streptococcus bacteria. Antibodies are proteins our bodies produce when they detect harmful substances, such as bacteria. An antistreptolysin titer greater than 166 Todd units (or >200 IU) is considered a positive test. This upper limit of normal may vary from lab to lab and by age, with it being higher in school-aged children. You will need the test if you have symptoms of a previous infection by group A streptococcus. Some illnesses caused by this bacteria are: - Bacterial endocarditis, an infection of the inner lining of your heart - A kidney problem called glomerulonephritis - Rheumatic fever, which can affect the heart, joints, or bones - Scarlet fever - Strep throat The ASO antibody may be found in the blood weeks or months after the strep infection has gone away. I would advise you to visit a MD general medicine for the ASO titre results so that it can be clinically correlated and for the status of the fissure you should meet a general surgeon so that you can be examined physically.