Roach allergies are a legitimate concern. Some studies show inner city children range from 17-59% sensitivity to roach allergens. Allergies can be created from roach frass (excrement) and caste skins. If cockroaches are a problem indoors, inspect suspected infested rooms 2 hours after normal lights out time. This may provide you with harborage area clues to improve treatment success. Reduce hiding places, especially with German roach infestations. Cleanliness will help tremendously, and reduce the population.