After suffering two years of constant cold symptoms , this summer I suggested to my doctor that I thought it could be allergy related, we tried Piriton, which worked great , no more cold symptoms HOWEVER I fear that it caused my DS5 to become aggressive and agitated. I have been back to the doctors with my concerns and was prescribed flixonase nasal spray but his cold symptoms returned (he gets so poorly needing time off from school, he gets allergic shiners under his eyes etc). Within the past few weeks his blood tests have concluded he is allergic to house dust mite, (we have replaced carpets with wood floor and taken other preventative measures), doctor since prescribed Cetirizine, but again his cold symptoms returned, so back to doctors to try Piriton again and no cold symptoms but his bad mood and aggression have returned. I have tried explaining to school my thoughts on his bad behavior being linked to Piriton, however I get the feeling that they just think I'm trying to give excuses. Has anybody else experienced a change in child's personality using Piriton? What other medications could I try? At a lose what to do ........