pederin and Necrosis

This irritant blister dermatitis is caused by the genus Paederus whose geographical distribution is worldwide, with a higher incidence in tropical areas. It is induced by direct skin contact with pederin, a blistering and caustic substance found in the abdomen (coelome) of Paederus insects (insect order Coleoptera: family Staphylinidae). The diagnosis is based on the presence of typical clinical features combined with compatible epidemiological features. Our goal is to describe the epidemiological and clinical features of this irritant contact dermatitis in Cameroon through a retrospective study conducted at the end of the rainy season at the Oku Hospital in Northwest Cameroon and to also include cases reported at the medical center of the French Embassy in Yaounde during this same timeframe. In addition, we conducted a literature review of paederus dermatitis. Nineteen patients were included in this study. More than half of the patients presented with more than two lesions predominantly localized to the face or the neck; less than half had complications manifesting as either localized or respiratory reactions and three patients presented periorbital involvement. This study confirms the presence of paederus dermatitis in Cameroon. It is mainly localized in the unusual geoclimatic region of the western high mountains within the country, as well as the usual warm, moist areas of Yaounde. The clinical evolution of this dermatitis is usually one of spontaneous and uneventful resolution with complications being rare. Curative treatment is one of localized topical therapies while oral antibiotic therapy should be reserved for more complicated cases.

Topics: Altitude; Animals; Cameroon; Coleoptera; Dermatitis, Irritant; Diagnosis, Differential; Ecosystem; Humans; Irritants; Lymphocytes; Necrosis; Pyrans; Seasons

In Egypt, the rove beetle; Paederus alfierii Koch, is an active predator of several insects pests attacking a wide variety of cultivated plants as maize, cotton, clover ... etc. On the other hand, members of genus Paederus contain pederin (potent toxin) which in contact with human skin causes a necrotizing lesion (dermatitis linearis) and with the eye causes conjunctivitis. After the sudden flood of the year 1994, this beetle attacked a factory and about forty factors suffered a form of contact dermatitis and conjunctivitis. The majority of such factors needed hospitalization. To fill the gap in the knowledge of medical importance on such a predator, the present investigation was aimed. The aqueous extract from twenty wild collected adults (0.0101 gm) was tested on different groups of albino mice. No cutaneous reaction was seen macroscopically. On the other hand, another group of mice (3/4) showed mild conjunctival congestion faded on the next day. However, these experimental findings do not indicate the innocence of this rove-beetle from being harmful to man. The discussion was given on the light of work done abroad.

Topics: Agriculture; Animals; Coleoptera; Conjunctivitis; Dermatitis, Contact; Gossypium; Humans; Insecta; Mice; Necrosis; Poaceae; Predatory Behavior; Pyrans; Skin; Toxins, Biological; Zea mays