Red Rash on upper body

My baby has developed a red blistery rash over her upper body – but I don’t think its heat rash as it’s not in the folds. What else could it be?

Over half of all newborns develop an uneven red blistery rash over their upper bodies, known as Erythema Toxicum. This is a scary name for a condition which is not harmful to your baby and disappears on its own within a few days.