Erythema Multiforme Treatment

1)    Antihistamines – “Cross classes”.  There are 5 classes of antihistamines and you can get some synergy from alternating them.  Being a little old fashioned and cost conscious I tend to alternate promethazine(6.25/5) and hydroxyzine (15/5 – 0.5mg/kg/dose) every 4 hours while awake for 5 days. For simplicity (and not to confuse the pharmacists) I usually use the same dose for both.

2)    H2 Blockers – usually ranitidine for 5 days (4 – 8 mg/kg/day div bid – it comes 15/5).

3)    Prelone or Pediapred  for 5 days (1-2 mg/kg/day div bid)