Household papular urticaria.

BACKGROUND: Papular urticaria often occurs after bites of insects such as mosquitoes, sandflies, bed bugs and fleas. Multiple bites and local pruritus are characteristic symptoms. Treatment is usually symptomatic and includes antihistamines and corticosteroids. The reappearance of the symptoms can be prevented by successful control of the parasite.

OBJECTIVES: To find the causative agent of papular urticaria in afflicted households with involvement of numerous family members, all in a narrow geographic area.

PATIENTS: We describe the cases of 20 patients belonging to seven families, who presented to the local primary clinic, suffering from papular urticaria.

RESULTS: The cat flea, Ctenocephalides felis, was the hematophagous insect responsible for all infestations. The pruritus and the papular urticaria were treated symptomatically with calamine lotion, topical corticosteroids or oral antihistamines. All clinical symptoms disappeared within a few weeks after effective control of the parasites by spraying and fumigating the infested locations.

CONCLUSIONS: Thorough investigation--including, at times, environmental inspection--is necessary to reach the rewarding discovery of the etiology of household papular urticaria. This condition may arise in other environments of similar character.