Allergy to cockroaches: A condition that manifests as an allergic reaction when one is exposed to tiny particles from cockroaches. Asthma can be due to exposure to cockroach allergens (allergy-provoking substances). These substances are the proteins shed or excreted by the cockroaches.

In a study reported in the Journal of Allergy and Clinical Immunology (1999;103:501-506), the families of asthmatic children sensitive to cockroach allergens were visited twice by professional pest controllers and were encouraged to clean their homes thoroughly to eliminate cockroach food sources and remove dead cockroaches and dust after the pest-control visits. These valiant efforts cut the allergen levels but only for a few months and only to levels still capable of causing asthma. Many homes are so contaminated that reservoirs of allergen exist on carpets, rugs, appliances and furniture. Removing cockroach allergen from the home is not an easy job.