Scorpion stings in children in the Asir Province of Saudi Arabia

Transcription

1 Journalof Wilderness Medicine 4, (1993) ORIGINAL ARTICLE Scorpion stings in children in the Asir Province of Saudi Arabia S.H. ANNOBIL, MD, FRCP Departmentof Child Health, College of Medicine, King Saud University, Abha, Saudi Arabia Scorpion stings are an important cause of morbidity in children in the southwestern region of Saudi Arabia. There appear to be regional variations in the clinical effects of scorpion stings, due to the different species of scorpions found in the various regions of the Arabian Peninsula. A prospective study on 47 children following scorpion stings in the Asir province of Saudi Arabia revealed that neurological manifestations were the most prominent. These included local pain, fright, restlessness and vomiting. One patient had disseminated intravascular coagulopathy and intracranial hemorrhages demonstrated on cranial computed tomography. There was one death due to severe pulmonary edema and congestive heart failure. The complications in these two patients followed stings by Nebo hierochonticus scorpions. The commonest identified scorpion was Leiurus quinquestriatus. The others were Compsobuthus werneri, Androctonus crassicauda and Scorpio maurus. Antivenom was given in all cases with systemic manifestations of envenomation. Key words: scorpion stings, childhood, Saudi Arabia Introduction Scorpion stings are encountered on nearly all continents, particularly in the tropics, semiarid and desert areas. About 500 species ofscorpions belonging to six families are known to exist, but only a small percentage is known to be dangerous to man [1]. A number of venomous scorpions are found in the Middle East. The scorpion fauna of Saudi Arabia includes 14 species or subspecies belonging to three families: the Buthidae with eight genera, Androctonus, Parabuthus, Leiurus, Buthacus, Compsobuthus, Orthochirus, Apisthobuthus and Vachonioulus; the Scorpionidae with two genera, Hemiscorpious and Scorpio [2]; and the genus Nebo (Diplocentridae) with the scorpion Nebo hierochonticus [3]. There is a relative paucity of literature on the clinical effects and management of scorpion stings in the Arabian Peninsula. This contrasts with extensive reports from other parts of the world, where scorpion stings were also commonly encountered. Furthermore, documentation of the effects of scorpion stings in Saudi Arabia have been mostly in adults [4-7]. This paper reports a prospective five-year study of the clinical manifestations and treatment of venemous scorpion stings in children in the Asir Province of Saudi Arabia (Fig. 1), and compares the findings with those from other regions Chapman & Hall

2 242 Annabil Patients and methods A prospective study was carried out on all children up to the age of 12 years admitted with scorpion stings to Abha General and Asir Central Hospitals, Abha, in Asir Province of Saudi Arabia (Fig. 1) during a five-year period (July 1986 to June 1991). A total of 47 children were admitted through the emergency room for observation or referred from other hospitals for further management following scorpion stings. There were 34 boys and 13 girls, a ratio of 2.6: 1. About half of the children were between two and five years of age and 25% were between the ages of nine and twelve years (Table 1). Sixty-two per cent of the children came from the lowlands of Tihama and 38% from the highlands of the Asir province. Details of the history, including personal data, area of domicile, site of the sting, time of the sting, interval between the sting and attendance in the hospital, presenting symptoms and signs, and past history of previous scorpion stings, were recorded. This was followed by a complete physical examination. The laboratory investigations included complete blood count, prothrombin and activated partial thromboplastin times, and fibrinogen levels in 44 children. There was no facility for fibrin degradation products assay. Biochemical tests were done in 40 of the 47 children. Chest radiographs and electrocardiography were carried out in 30 of. the children. The management of the three major clinical presentations (groups) in children following scorpion stings are outlined in Tables 4, 5 and 6. Fig. 1. Map of Saudi Arabia showing the location of Asir province.

3 Scorpion stings in Saudi Arabia 243 Results In 85 % of cases, the stings were on the feet or hands (Table 2). Eighty-five per cent of the victims were brought to the hospitals within 3 h of sustaining the stings, 12.7% within 3-6 h, and one child (2.3%) after 39 h. This child lived in a remote area and her parents initially used local herbs. She subsequently developed an abscess at the site of sting and needed surgical intervention. In 26 of the patients (55%), the stings occurred in the evening and at night. Eighty-one per cent of the stings occurred in the summer months, when the temperatures in the lowlands of Tihama ranged from C and those of the highlands were C. There was a high incidence (47%) in the 2-5 year age group, who were fond of playing bare-footed outside their homes and also of exploring the sand and crevices under stones, where scorpions usually reside. The next most frequent age group was the 9-12-year-old (26%), many of whom were out in the fields tending their flocks of goats and sheep. Table 1. Age and sex distribution in childhood scorpion stings Agein years Male Female Total Lesthan Table 2. Part ofbody stung in childhood scorpion stings Part ofthe body Number(%) Lower limb: Upper limb: Scapula Head and Neck: Total Toe Foot Ankle Lower leg Finger Hand Elbow Head Neck 3 ( 6.38) 26 (55.31) 1 ( 2.31) 2 ( 4.26) 8 (17.02) 3 ( 6.38) 1 ( 2.13) 1 ( 2.13) 1 ( 2.13) 1 ( 2.13) 47 (100) Scorpion species The scorpion species could not be identified in 24 of the 47 cases (51%) because the parents threw them away. In 23 (49%) cases, the scorpion species was identified as

4 244 Annobil 11111' ' II \ \ Fig. Z. Leiurus quinquestriatus /"ljlll/iiii"i/ii1iii1i/"i/1ii1/"il!'l1l111'!111i1"11i111\" II o Fig. 3. Nob..,. J.;~

5 Scorpion stings in Saudi Arabia 245 L. quinquestriatus (18) (Fig. 2), N. hierochonticus (2) (Fig. 3), A. crasssicauda (1), S. maurus or C. werneri, (one each). Clinical manifestations The clinical manifestations following scorpion stings appeared within 6 h, although a few occurred within 1-2 h. The clinical symptoms included anxiety, fright, pain, vomiting, profuse sweating and increased salivation. The signs were mainly swelling, redness and tenderness around the site of the sting (Table 3). The clinical effects of scorpion stings in children were varied, but could be broadly grouped: (a) children who experienced severe localized pain, but no systemic manifestations; (b) children who in addition to pain presented with mild systemic features such as vomiting, increased salivation or excessive sweating; (c) children who presented with toxic manifestations such as pulmonary edema with or without central nervous system signs such as restlessness, convulsions, priapism, and coma, with or without general paralysis. Table 3. Clinical manifestations in childhood scorpion stings (n = 47) Feature No. a/patients (%) Symptoms: Pain (crying) Fright!restlessness Vomiting Profuse sweating Increased salivation Drowsiness Numbness Bleeding from site of sting Frequent urination Abdominal pain Stridor Generalized seizures Signs: Puncture site Local swelling Local redness and swelling Local redness Tenderness Priapism Peripheral cyanosis Increased bronchial secretions Hypotension (systolic BP < 60 mm) Local enlargement and tenderness ofregional lymph node Retinal hemorrhage Papilledema 20 (43) 12 (26) 10 (21) 7 (15) 7 (15) 4 ( 9) 2 ( 4) 2 ( 4) 2 ( 4) 1 ( 2) 1 ( 2) 1 ( 2) 13 (28) 9 (19) 8 (17) 7 (15) 5 (11) 4 ( 9) 4 ( 9) 3 ( 6) 2 ( 4) 2 ( 4) 1 ( 2) 1 ( 2)

6 246 Annobil Table 4. Major clinical presentations and group classification of children with scorpion stings in Asir Province of Saudi Arabia Group A GroupB GroupC Clinical presentation Severe localized pain Pain and mild systemic Toxic manifestations only feature No. of children Mean age 6 years 1 month 5 years 1 month 3 years 7 months Male:female ratio 21:10 10:1 3:2 Sting: L. quinquestriatus N. hierochonticus 2 S. maurus 1 C. werneri 1 A. crasicauda 1 Hematology In 44 patients, complete blood count, prothrombin time. activated partial thromboplastin time and fibrinogen levels were normal, except in one child in whom the activated partial thromboplastin time was 53 s (control 25 s) with fibrinogen level of 0.96 g 1-1 (normal range 2-4 g 1-1). Blood chemistry Of the 40 patients who had blood chemistry investigations, electrolytes, urea and creatinine were normal in 39. One child developed acute renal failure with blood urea of 298 mg dl- t, creatinine of 5.1 mg dl- t and potassium of 6.5 mmoll- t 36 h after the scorpion sting. This was successfully treated by peritoneal dialysis. Table 5. Management of the three groups of scorpion stings in Asir region of Saudi Arabia Group A (n = 31) GroupB (n = 11) GroupC (n = 5) Paracetamol Lidocaine (local) Promethazine Scorpion antivenom Antibiotics Tetanus toxoid Intensive Care Unit Fatality

7 Scorpion stings in Saudi Arabia 247 Chest radiography Out of 30 patients who had chest radiography, three showed changes consistent with pulmonary edema. Electrocardiography Thirty patients had electrocardiograms, which were normal in 28; two showed sinus tachycardia and in one of these, there were also inverted T waves in many leads with non-specific ST changes. This child died 10 h after the scorpion sting. Unfortunately, permission was not granted for an autopsy. Length ofstay in hospital Thirty-one (66%) of the children were kept in the hospital for 8-24 h, 11 children (23%) for 2-3 days and the remaining five children for 5-8 days. Management In the 31 children with only localized pain, seven had local infiltration of the sting site with 1-2% lidocaine; 30 also received an analgesic, paracetamol. Those with systemic effects of scorpion envenomation received Pasteur antiscorpion venom serum after skin testing for allergy. Five to twenty ml of serum diluted 1: 10 in isotonic sodium chloride solution was administered by slow intravenous infusion, depending upon the severity of the systemic manifestations. This serum is highly purified and contains the antivenom to Androctonus, Buthus and Leiurus species. Of the 11 children with pain and mild systemic features, such as vomiting and excessive salivation, six received the antihistamine promethazine for excessive vomiting and ten received antiscorpion venom serum. One child developed local allergic reaction to skin testing and was not given the serum. Five children with toxic manifestations were admitted to the intensive care unit for monitoring of vital signs and for resuscitative measures. Two required ventilatory support and frequent suction of excessive pharyngeal secretions, in addition to the other drugs used (Table 6). Atropine was not used in any child because none had severe bradycardia. Mortality There was one death from severe pulmonary edema, congestive cardiac failure and probable toxic myocarditis. Discussion Scorpion stings accounted for 0.35% of all pediatric medical admissions to the Abha General and Asir Central Hospitals in Abha during the five-year period. This incidence may not be a true reflection of scorpion stings in the area, since the study was hospital based. Many affected children, especially in rural areas, may not be taken to a hospital for treatment. The use of local herbs for the treatment of scorpion stings is known to be a popular practice in the Asir province. Pain was a significant clinical feature in only 20 (43%) of cases, while it was considered a hallmark of scorpion stings in both children and adults as described by EI Naggar [8] in western Saudi Arabia. In this study, neurological manifestations were more prominent than the cardiovascular complications (Table 3). This was similar to the

8 Ṇ j::.. 00 Table 6. Details of the management ofthe five children in Group C admitted to intensive care unit I. V. Fluid Oxygen Hydrocortisone Frusemide Diazepam Digoxin Calcium & potassium supplements Peritoneal dialysis Suction of excessive secretions Assisted ventilation with PEEP I.V.: Intravenous PEEP: Positive end expiratory pressure ~ ::s ::s c I::r' :::.:

9 Scorpion stings in Saudi Arabia 249 observation of Elnumeiri in children with scorpion stings in western Saudi Arabia. Most of the neurological manifestations encountered in this study were due to L. quinquestriatus. On the other hand, Brennan et ai. [5], from the AI Baha region, also in southwestern Saudi Arabia, noted that in adults the cardiovascular complications were the most predominant, again where the major scorpion species was L. quinquestriatus. In human scorpion envenomation, victims may have abnormalities in coagulation, including disseminated intravascular coagulation and resultant hemorrhages [9] or slight abnormalities without any bleeding [5]. Some observers have not encountered such changes [10]. In the present series, abnormal coagulation due to disseminated intravascular coagulopathy was observed in one child. This manifested as fundal hemorrhages, temporary blindness and deafness. There were cerebral and cerebellar hemorrhages confirmed on cranial cr scans. The scorpion in this victim was identified as N. hierochonticus [11]. Pulmonary edema occurred in three children, of whom two survived and one died. The pathogenesis of the acute pulmonary edema following scorpion envenomation is complex, but experimental animal data have shown that it is related at least in part to the heart failure induced by catecholamines released by scorpion venom [12]. In the only child who died, there Was persistent hypotension, severe pulmonary edema and cardiac failure, probably due to toxic myocarditis as evidenced by electrocardiographic changes. Again, N. hierochonticus was the identified scorpion. In contrast, Rosin could find no clinical data available in Israel on stings by N. hierochonticus, but described the local reaction of pain, itching, swelling and scab formation in two human volunteers [13]. The severe cases of scorpion poisoning in this study with pulmonary edema with or without central nervous system manifestations required support of the vital functions, including intravenous doses of scorpion antivenom to neutralize the circulatory venom and to reduce its toxic effect [12,14]. The use of antivenom in scorpion stings has raised controversy and diverse opinions. Some have stated that 'there is no value of antivenom in the treatment or prevention of the cardiovascular manifestations of scorpions' [16]. Others felt that the clinical picture was not deemed severe enough to warrant the risk of its usage [7], or that it should be used only in severe cases [5]. On the other hand, Campos et ai. [14,15,17] on the basis of experimental and clinical studies, recommended intravenous injection of antivenom, especially in children with systemic effects of envenomation immediately after admission to the hospital. This was to neutralize the circulating venom and that which was being absorbed from the site of the sting into the circulation. As the antiscorpion venom serum is prepared from horses, the known side effects include primary allergic and anaphylactic reactions or even shock in rare instances. However, out of the 15 children who received Pasteur antiscorpion sera, only one developed wheals and redness at the test injection site and thus was not given the serum. The mortality rate in this study was 2%. Brennan et ai., in a predominantly adult study in the AI Baha region, southwestern Saudi Arabia, used antivenom only in severe cases and also reported a fatality rate of 2.3% [5]. However, in Brazil a mortality rate of 3.5% was reported. When only those who were given antivenom were considered, the fatality rate was 1.8% [18]. This was further decreased to 0.26% when severe cases received intensive care management and antivenom [14,15]. We submit a local protocol for the management of scorpion stings in children. (a) Pain should be alleviated using local anesthesia and administration of analgesics such as

10 250 Annobil paracetamol. Promethazine may be given to allay restlessness or fright and to control vomiting. (b) Antivenom should be given at the earliest sign of systemic envenomation after skin testing. (c) The patient needs close observation for h after the symptoms have subsided, to identify relapse from further absorption of venom. Persons with respiratory or circulatory instability should be accompanied by medical personnel well versed in intubation and resuscitation during transfer to a hospital with intensive care facilities. (d) In severe cases with pulmonary edema, intravenous antivenom, furosemide and hydrocortisone are administered. Digoxin is used for sinus tachycardia and diazepam for control of seizures. Atropine was not used in any of the children, as none had severe bradycardia resulting from the scorpion venom. It has been shown that it potentiates the hypertensive effect and increases severity of pulmonary edema induced by scorpion toxin in experimental animals [17]. Nebo hierochonticus envenomation deserves closer monitoring, not only for the cardiopulmonary complications, but for evaluation of any bleeding manifestations. This may only be evident on examination of the fundi and assessment of the coagulation profile. On suspicion of intracranial bleeding, cranial cr scan is indicated. The offending scorpion should be sent to the hospital for identification. Prevention is important. Children should wear shoes when they go out to play after sunset. Parents and guardians should also pay particular attention to environmental sanitation by clearing and spraying areas outside their homes to reduce the number of scorpions and hence the risk of stings. Acknowledgement I thank Dr Abdulkarim Nasher, Department of Zoology, College of Education, King Saud University, Abha, Saudi Arabia for his help with the identification of the scorpions. References 1. Yarom, R. Scorpion venom: a tutorial review of its effects in men and experimental animals. Clin Toxicol1970; 3, Vachon, M. Arat;hnids of Saudi Arabia: Scorpions. In: Wittmer, H.C. and Buttiker, W., eds. Fauna ofsaudi Arabia. Basle: Pro Entomologia, Ciba-Geigy Ltd, 1979: 1; Francke, O. Revision of the genus Nebo Simon (Scorpiones), Diplocentridae. J Arachnol 1980; 8, Goyffon, M. and Vachon, M. Arachnids of Saudi Arabia, note on poisoning accidents through scorpions in Saudi Arabia. In: Wittmer, H.C. and Buttiker, W., eds., Fauna of Saudi Arabia. Basle: Pro Entomologia, Ciba-Geigy Ltd., 1979: 1; Brennan, R., Kumar, E. and Jaggarao, N. Scorpion stings in the Al Baha region. Saudi Med J 1989; 10, Elnumeiri, M. Scorpion sting: a medical emergency. Postgrad Doctor (Middle East) 1987; 10, Neale, J.R. Scorpion sting syndrome in Eastern Riyadh. Ann Saud Med 1990; 10, El-Naggar, M.K., Wahab, A.A. and Montasser, M.F. Clinical patterns of scorpion stings in Saudi Arabia. J Egypt Soc Parasitol1985; 15, Reddy, C.R.R.M., Suvarnakumari, G., Devi, C.S. and Reddy, C.N. Pathology of scorpion venom poisoning. J Trop Med Hyg 1972; 75, Gajalakshmi, B.S. Coagulation studies following scorpion venom injection. Ind J Med Res 1982; 76,

11 Scorpion stings in Saudi Arabia Annobil, S.H., Omojola, M.F. and Vijayakumar, E. Intracranial haemorrhage after Nebo hierochonticus scorpion sting. Ann Trop Paed 1991; 11, Freire-Maia, L., Almeida, H.O., Cunha-Melo, l.r., Azevedo, A.D. and Barroso, l. Mechanism of the pulmonary edema induced by intravenous injection of scorpion toxin in the rat. Agents Actions 1978; 8, Rosin, R. Sting of the scorpion Nebo hierochonticus in man. Toxicon 1969; 7, Campos, l.a., Silva, O.S., Lopez, M. and Freire-Maia, L. Signs, symptoms and treatment of severe scorpion sting in children. Toxicon 1979; 17 (suppl. 1), Campos, l.a., Silva, O.S., Lopez, M. and Freire-Maia, L. Signs, symptoms and treatment of severe poisoning in children. In: Eaker, D. :and Wadstrom, T., eds. Natural toxins. Oxford: Pergamom Press, 1980: Gueron, M. and Ovsyshcher, I. What is the treatment for the cardiovascular manifestations of scorpion envenomation? Toxicon 1987; 2, Freire-Maia, L., Campos, l.a. Response to the letter to the editor by Gueron and Ovsyshcher on the treatment of the cardiovascular manifestations of scorpion envenomation. Toxicon 1987; 25, Magalhaes, O.c. Scorpionism. J Trop Med Hyg 1938; 41,