Photoclinic: Immediate Pressure Urticaria

An otherwise healthy 10-month-old boy was brought to an allergy clinic for evaluation of atopic dermatitis and chronic rhinitis. On arrival at the clinic for aeroallergen and milk prick skin testing, a rash was noted that was different from his usual atopic dermatitis. The rash had not been present 2 hours earlier when the mother dressed the child and placed him in his car seat during the ride to the clinic.