Infectious mononucleosis is an infective disease caused by the Epstein-Barr virus. The classic symptoms of infectious mononucleosis include: sore throat, fever, fatigue, weight loss, and malaise. Limphadenopathy (enlarged lymph nodes), splenomegaly (enlarged spleen) and hepatitis (inflammation of the liver) might be present as well.
Once the liver is affected, its cells do not work at their full capacity. They fail to perform one of their functions which is processing bilirubin from the blood, so it can be expelled in the intestines. Therefore, the bilirubin is accumulated in the blood, leading to yellowish color of the skin, more often known as jaundice. The yellowish color originates from the yellowish color of the bilirubin. This jaundice should not be mistaken with the one caused by viral hepatitis infection (Hepatitis A, B or C).
The treatment might include non-steroidal anti-inflammatory drugs to reduce the inflammation. Antibiotics are used only if there is co-infection with certain bacteria. Otherwise, the antibiotics are useless against viral agents and the mononucleosis should self-limit itself.
You might want to visit a specialist for infective diseases for additional information about jaundice related to mononucleosis.