Hi, My 17 yr. old son has slightly raised billirubin and a slightly enlarged spleen . Through blood tests we ve ruled out hep a, b, c, mono and liver problems. He s been on 100mg amoxicillan for over 4 mos. for acne treatment . One of the side effects for long term use in males is yellowing of eyes (which is what we noticed that got all of this started). The drs. do not put much stock in the amox. being the reason. I read a study, too, that said tall healthy athletes (which he is all of those) have spleen sizes that are a bit larger than others. The study said up to 13 cm. My sons is 9x9x13cm. Could it be that this size is normal for my son? Or is the amox. causing this? He has absolutely no pain associated with the spleen. Thanks.