Late recall urticaria.

In the cases reported of recall urticaria, the clinical manifestations usually develop within an hour. We present the clinical case of an 11-year-old boy who, after 9 weeks of immunotherapy with pollen extracts (Phleum pratense and Festuca elatior), presented an urticarial lesion 48 to 72 h after of the injection on the opposite arm to where it had been applied and in the same place where the previous injections had been administered. This reaction continued for every injection given during the time that the immunotherapy was applied twice a week, and for the 6 weeks that it was applied once a week. Subsequently, the urticarial lesions appeared every two or three injections.