Clinical and Entomological Studies of Paederus Dermatitis

Kim, Young Pio; Chun, Inn Ki; Hur, Soo Gyoung; Ha, Bom Seock

Abstract

Paederus dermstitis (or dermatitis linearis), caused by the insect genus Paederus, is characterized by linear erythernatous, vesicopustular lesions. In 1968, we proved that causative agent is Paederus fuscipes. During the 20-year period since then (from June 1968 to September 1988), we have experienced 156 cases of the diseaes in our clinic, and the clinical features were studied with the following results. (1) They were found only during summer months from June to September. Most prevalent in June(47%), followed by August, July and September, in decreasing order. (2) People in their twenties were affected most often(10%), with females outnumbering males, by approximately 2.8 to 1. (3) The lesions were found exclusively over exposed areas, such as face, neck, and extremities (4) Experiments on a volunteer revealed that the same skin lesions as in the patients can be produced by rubbing the anal portion of the insect. (5) Spongiosis and subcorneal pustule of epidermis were the main histopathological findings. (6) The insects appear ant-like and measures 6.5 to 7mm in length. It has a black, round head with pslpuli black, rectangular, short elytra, yellowish brown pronotum and abdomen composed of 6 segments, of which two caudal ones(hypopygium) were dark brown. The meso and metathorax, and the lower ends of the femurs in meso and metapedes appear dark brown. (7) Wide use of potent pesticides, herbicides, or insecticides as well as the urbanization may have reduced the out breaks of the disease in recent years.