PAEDERUS DERMATITIS AMONG MALAYSIAN UNIVERSITY STUDENTS CASE SERIES DERMATITIS CAUSED BY PAEDERUS FUSCIPES CURTIS, 1840 (COLEOPTERA: STAPHILINIDAE) IN STUDENT HOSTELS IN SELANGOR, MALAYSIA CC Heo1, B Latif1, WM Hafiz1 and HZ Zhou2 1Faculty of Medicine, Universiti Teknologi MARA, Sungai Buluh Campus, Jalan Hospital, Sungai Buluh, Selangor, Malaysia; 2Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Chao Yang, Beijing, PR China Abstract. We report a series of dermatitis cases caused by the staphilinid beetles, Paederus fuscipes Curtis, among university students staying in the residential col- lege in Puncak Alam, Selangor, Malaysia from 1 January to 31 December 2010. A total of 360 cases (6.0%) were recorded in the Student Health Center throughout the year; the majority of patients stayed at a hostel near an oil palm plantation. Skin symptoms included erythema, edema, vesicular papules, painful blisters, burning sensation, pruritus, hyper pigmentation and peeling of skin. The com- monly involved sites were the face, neck, shoulders and arms. Most students noticed the symptoms upon awakening in the morning. The patients were treated with fusidic acid cream and the symptoms resolved within 5 days. These beetles are nocturnally active and enter the room whenever a light source is available. The unintentional crushing of these beetles during sleep causes the release of its hemolymph (paederin) which is the cause of the dermatitis. Keywords: Paederus fuscipes, dermatitis, student hostel, Malaysia INTRODUCTION and consists of approximately 621 spe- cies, with its only absence in Antarctica Medically important beetles are (Frank, 1988). The body sizes of the adult mainly from the families Meloidae, beetles are 7-10 mm long and 0.5 mm wide Oedemeridae and Staphilinidae (Nik- (George and Hart, 1990). They have a bakhtzadeh and Tirgari, 2008). The rove black head; the pronotum and abdominal beetle, Paederus fuscipes Curtis, 1840, is a segments III to VI are orange, the elytra member of the family Staphilinidae, order is metallic blue and abdominal segments Coleoptera (Li and Zhou, 2009). The genus VII to VIII are black. The appendages are Paederus is widely distributed worldwide partly orange and partly black. The bright Correspondence: CC Heo, Faculty of Medicine, colors of Paederus are a warning sign Universiti Teknology MARA, 40450 Shah Alam, (aposematism) to potential predators that Selangor, Malaysia. they are venomous and inedible (Lott and Tel: +6 (03) 5544 2862; Fax: +6 (03) 5544 2831 Anderson, 2011). Paederus beetles breed in E-mail: [email protected] moist areas, wetlands and salt marshes Vol 44 No. 2 March 2013 197 SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH among rotting vegetation; the beetles mentioned in the Exodus. appear to be predacious (Triplehorn and In Malaysia, paederus dermatitis Jonson, 2005). Although these insects was first reported in 1919 (Raju, 2002). are able to fly, they prefer to run; when Mokhtar et al (1993) reported an outbreak running, they frequently raise the tip of among 12 medical students in Universiti their abdomen (Triplehorn and Johnson, Sains Malaysia at Kubang Kerian Cam- 2005); this particular behavior is useful pus, Kelantan. The second outbreak was for identification (Vegas et al, 1996). Pae- reported in a primary school in Tereng- derus beetles are beneficial insects in the ganu involving 36 pupils (Rahman and agricultural sector because they prey on Norjaizah, 2008). In September 2002, two crop pests (Frank and Kanamitsu, 1987). thousand people living in high rise flats A study conducted in Malaysia found that and dormitories in Penang were affected Paederus fuscipes is an aggressive leafhop- by dermatitis caused by P. fuscipes. per predator in rice fields (Manley, 1977). We report a series of dermatitis cases Outbreaks of paederus dermatitis caused by the staphilinid beetles, Paederus have been reported in various countries, fuscipes, among the university’s students including Argentina (Dallas, 1939), Aus- who stay in Puncak Alam, Selangor, tralia (Todd et al, 1996), Brazil (Diógenes, Malaysia from 1 January to 31 December 1994), China (Li, 1990; Jiang et al, 2008; 2010. Huang et al, 2009), the Congo (Vasudevan and Joshi, 2010), Ecuador (Campos, 1927), CASE SERIES Egypt (Assaf et al, 2010), Guinea-Conakry The cases of dermatitis were first (Vanhecke et al, 2010), India (Verma and noted in July 2009 at university hostels on Agarwal, 2006; Padhi et al, 2007; Gnanaraj Puncak Alam campus, Selangor (3º 12’12’’ et al, 2007), Iran (Zargari et al, 2003; Ab- N 101º 27’5’’E) which is located about 47 basipour and Taghavi, 2005), Iraq (Al- km from Kuala Lumpur. There are 12 stu- Dhalimi, 2008), Italy (Gelmetti and Gri- dent colleges on the campus with around malt, 1993; Veraldi and Süss, 1994), Japan 6,000 students. (Armstrong and Winfield, 1969), Kenya (Van Schayk et al, 2005), Malawi (Deneys A total of 360 cases were recorded at and Zumpt, 1963), Namibia (Deneys and the Student Health Center throughout Zumpt, 1963), Nigeria (George and Hart, the year (Fig 1). The majority of patients 1990), Peru (Alva-Davalos et al, 2002), Si- stayed in a hostel located near an oil palm erra Leone (Qadir et al, 2006), South Korea plantation. The student ages ranged 18-20 (Kim et al, 1989; Kim et al, 1995), Sri Lanka years. The skin symptoms included ery- (Kamaladasa et al, 1997), Sudan (Lewis, thema, edema, vesicular papules, painful 1958), Taiwan (Huang et al, 2010), Tanza- blisters, burning sensation, pruritus, line nia (Fox, 1993; Mbonile, 2011), Thailand lesions, hyper pigmentation and skin (Papasarathorn et al, 1961; Suwannahi- peeling. tatorn et al, 2007), Turkey (Sendur et al, The common sites of involvement 1999), Uganda (McCrae and Visser, 1975) were the face, neck, shoulders and arms and Venezuela (Rivas et al, 2001). Norton (Fig 2), while the other parts of body, and Lyons (2002) even proposed the inva- such as the periorbital region, chest, sion of paederus dermatitis in Egypt by abdomen and legs were rarely involved. Paederus alfierii as the plagues that were Most students noticed the symptoms 198 Vol 44 No. 2 March 2013 PAEDERUS DERMATITIS AMONG MALAYSIAN UNIVERSITY STUDENTS A B C D Fig 2–Sites of involvement (arrow) seen in paederus dermatitis cases. A, face (chin area); B, neck; C, right shoulder; D, left forearm. Note the typical line lesion in A, B and D. 80 Paederus dermatitis cases in 2010 upon arising in the morning. Some of the 70 students sought medical treatment at the 60 Case Student Health Center, which is located 50 on the campus, but many ignored their 40 symptoms or self-treated, with antiseptic 30 cream or calamine lotion. Those who saw 20 the medical officer at the Health Center 10 were prescribed fusidic acid cream and 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec the symptoms resolved within five days. In some cases linear scars and hyper pig- mentation developed and persisted after Fig 1–Total cases of paederus dermatitis record- ed at the Student Health Center at Pun- treatment. cak Alam campus, Universiti Teknologi The students found a large quantity of MARA in 2010. these beetles around their residences. The Vol 44 No. 2 March 2013 199 SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH DISCUSSION Paederus dermatitis may affect peo- ple of any sex, age, race or socioeconomic status. The risk depends on the parson’s activities and the insect habitat, exposed skin areas are at higher risk (Singh and pronotum Ali, 2007). The incidence of paederus der- matitis increases during the rainy season (Mokhtar et al, 1993; Vegas et al, 1996; elytra Frank and Kanamitsu, 1987). Rahmah and Norjaiza (2008) noted there was more rainfall in February 2005 than February 2004; this could be an explanation for the increase in these beetles. In Tanzania, paederus dermatitis and conjunctivitis oc- curs during the rainy season in the north (Fox, 1993). Recently, Senel and Sahin (2011) stated global warming may cause Paederus fuscipes Fig 3–Adult beetle of (Coleop- an increase in the incidence of paederus tera: Staphilinidae). The length of elytra dermatitis, since higher temperatures is longer and wider than the pronotum. influence the ecological dynamics of the insect species. beetles were found in their rooms, in the In our study, the peak incidence was corridors, in the toilets and on the walls. noticed from June to August 2010. This Most of the students claimed to have no may be due to the matriculation of new previous history of skin allergies. They students at that time. Many new students had been warned by the senior students became aware of the skin condition for regarding the skin lesions caused by an the first time, having never been exposed ant-like insect, which they call semut to this kind of skin condition before. The kayap, semut semai or charlie. However, incidence decreased after September. not all students were able to recognize the Most of the patients did not seek treat- Paederus beetles correctly. ment at the Health Center; as they may We carried out an entomological in- have gotten used to the situation, ignored vestigation to identify the etiologic agent the symptoms or self-treated. There was that caused the dermatitis outbreak. Beetle a semester break at the end of the year. specimens were collected from the student Hence, only few cases were reported. We rooms, toilets and the hostel corridors. assume the actual incidence was higher The specimens were preserved in 70% but many cases were not reported to the ethanol and then sent to the last author Student Health Center. for identification. The beetles were subse- The Paederus beetle does not bite or quently confirmed to beP. fuscipes (Fig 3). sting, but releases toxic hemolymph when Paederus fuscipes is identified based it is accidentally crushed on the skin; this on the features described by Lott and hemolymph produces an inflammatory Anderson (2011).