In the past i never had a problem with taking acetaminophen, now a small round itchy rash shows up on my right hand between my thumb & index finger hours after taking it. why? i'm on apixaban, what else can i take if i can't take acetaminophen?

Rarely, an allergic reaction manifests with just one single rash, it could be coincidental, especially you have taken Acetaminophen without problem in the past. Rash is not a dangerous reaction so it is a true allergic rash, I would advise you to re-challenge with Tylenol (brand name). If you are really allergic with Acetaminophen, you can take Ibuprofen for fever, pain, etc.., even with Apixaban.