Cold sores are caused by the herpes simplex type 1 virus and are contagious whereas canker sores are not. Also, cold sores can appear outside the mouth in places such as under the nose, on the lips or under the chin while canker sores always appear inside the mouth.anker sores, or aphthous stomatitis, are small ulcers in your mouth that cause pain and discomfort when talking or eating. Canker sores come in two varieties: simple and complex.
Codeine, which is found in many pain relievers, may cause a false positive for morphine or heroin because of its similar chemical structure. Antibiotics. Certain newly developed antibiotics including amoxicillin and ampicillin have been reported to cause false positives for cocaine. DHEA
I do agree with your doctor. HIV testing is known to give false positive results. Since your repeat? p24 antigen and western blot are negative and viral load is undetectable, your ELISA is a false positive result. The fever and sore throat was possibly just a mild flu and antibodies produced against the flu virus can cause false positive HIV tests. Using a handkerchief with indirect exposure to genital secretions is highly unlikely to result in a HIV infection.