Hives reaction to Hep B vaccine?

  My child had his first Hepatitis B this week.  Within 24
  hours he began having a hives reaction and now four days
  later it covering his whole body.  He's on anithistimes
  but continues to break out in new hives.  Does this
  vaccine produce this type of reaction?  If so, should
  he continue the series?  Are there any test mechanisms
  available to decide if this is a coincidence or the
  result of the vaccine? He's 11 and has not had a hive
  reaction in 5 or 6 years.  He has only had this type
  of reaction to antibiotics (penicillin, ceclor, sulpha).
  Could any of these antibiotics be part of the serum?
  Thanks for your help,
  Linda  

[HFHSM.D.-D.M.]

Dear Linda:
The hepatitis B vaccine has been reported to cause allergic and urticarial (hives) reactions in a small number of people receiving it.  It is certainly a possibility that you son