History:

Papular urticaria is a term used to describe clusters of itchy papules usually seen on the limbs of young children.They are usually due to flea bites from cats or dogs and also bites from mosquitoes. These bites commonly become secondarily infected after they are scratched.Generally  the lesions are on the lower legs.There may be small vesicles superimposed on the urticarial lesions but they are usually quickly traumatised and burst leaving a crust.Papular urticaria is an allergic hypersensitivity reaction to bites.This may mean that other members of the family are be being bitten as well but will not respond in the same florid manner.

The following reference in JAAD  is the most recent on the topic