Scorpion envenomation among children: clinical manifestations and outcome (analysis of 685 cases)

Our objective was to characterize both epidemiologically and clinically manifestations after severe scorpion envenomation and to define simple factors indicative of poor prognosis in children. We performed a retrospective study over 13 years (1990-2002) in the medical intensive care unit (ICU) of a university hospital (Sfax-Tunisia). The diagnosis of scorpion envenomation was based on a history of scorpion sting. The medical records of 685 children aged less than 16 years who were admitted for a scorpion sting were analyzed. There were 558 patients (81.5%) in the grade III group (with cardiogenic shock and/or pulmonary edema or severe neurological manifestation [coma and/or convulsion]) and 127 patients (18.5%) in the grade II group (with systemic manifestations). In this study, 434 patients (63.4%) had a pulmonary edema, and 80 patients had a cardiogenic shock; neurological manifestations were observed in 580 patients (84.7%), 555 patients (81%) developed systemic inflammatory response syndrome (SIRS), and 552 patients (80.6%) developed multi-organ failure. By the end of the stay in the ICU, evolution was marked by the death in 61 patients (8.9%). A multivariate analysis found the following factors to be correlated with a poor outcome: coma with Glasgow coma score ≤ 8/15 (odds ratio [OR] = 1.3), pulmonary edema (OR = 2.3), and cardiogenic shock (OR = 1.7). In addition, a significant association was found between the development of SIRS and heart failure. Moreover, a temperature > 39°C was associated with the presence of pulmonary edema, with a sensitivity at 20.6%, a specificity at 94.4%, and a positive predictive value at 91.7%. Finally, blood sugar levels above 15 mmol/L were significantly associated with a heart failure. In children admitted for severe scorpion envenomation, coma with Glasgow coma score ≤ 8/15, pulmonary edema, and cardiogenic shock were associated with a poor outcome. The presence of SIRS, a temperature > 39°C, and blood sugar levels above 15 mmol/L were associated with heart failure.     

Scorpion Stings and Antivenom Use in Arizona

BackgroundArizona's rugged desert landscape harbors many venomous animals, including a small nocturnal scorpion, Centruroides sculpturatus, whose venom can cause severe neuromotor disturbance. An effective antivenom is available at selected health care facilities in the state.MethodsWe analyzed 4398 calls of scorpion stings to the Arizona Poison and Drug Information Center (APDIC) in Tucson over a period of 3 years, from January 2017 to December 2019.ResultsWe followed 1952 (44.4%) of the victims to resolution. We excluded 2253 callers with minimal effects of the sting and 193 victims with possible toxic effects who were lost to follow-up. The most common complaints among callers were pain at the sting site in 88.9% and local numbness in 62.2%. Detailed clinical information was obtained from 593 calls from a health care facility. Neuromotor signs consistent with C. sculpuratus envenomation included nystagmus in 163 (27.5%), hypersalivation in 91 (15.3%), and fasciculations in 88 (14.8%). Antivenom (Anascorp; Rare Disease Therapeutics, Inc., Franklin, Tenn) was administered to 145 patients. Most were children <5 years old (n = 76, or 54.4%); 27 (18.6%) were 5-9 years old and 42 (30.0%) were ≥10 years of age. About half, 79 of 145 (54.5%) victims who received antivenom, met the APDIC recommended use criteria.ConclusionsPatients treated with antivenom exhibited a rapid resolution of symptoms without immediate or delayed hypersensitivity reactions. We recommend broadened availability of antivenom at sites where it is most needed.     

Jellyfish envenomation syndromes updated

Jellyfish venoms are mixtures of toxic and/or antigenic polypeptides and enzymes pathogenic to human beings. As newer therapeutic agents become available to treat the various reactions to stings caused by these animals, an accurate diagnosis of the type of reaction the patient experiences and of the offending species will be necessary. Fatal reactions may be caused either by anaphylaxis or by the action of toxins in the venom on the heart, respiratory center, or kidneys. Cutaneous eruptions after envenomation may be local, generalized, exaggerated, recurrent, delayed, persistent, or occur at sites distant from the primary sting. Fat atrophy, pigmentary changes, vasospasm, and contractures with gangrene can occur after jellyfish stings. Identification of the envenoming animal can be made by actual visualization, examination for nematocysts on skin scraping, or serologically. It may also be predicted based on knowledge of location, time, and environmental circumstances of the encounter. First-aid measures designed to prevent additional nematocyst rupture are species-specific. Anaphylaxis should be prevented by the appropriate lifesaving measures. Other syndromes, caused by the toxins of the venom or mediated by humoral or cellular immune mechanisms, should be treated specifically.     

Scorpion venom cardiomyopathy.

Cardiac function was evaluated by serial echocardiography in 30 children affected by scorpion stings. They could be separated into two groups on the basis of the initial echocardiogram. Group 1, consisting of 18 children, had normal left ventricular function, whereas group 2, consisting of 12 children, showed compromised left ventricular function (ejection fraction less than 0.55; fractional shortening less than 27%). In group 2 the left ventricular end-systolic dimension was increased significantly and the interventricular septal thickening fraction was depressed significantly, compared with group 1. Nine children in group 2 showed improvement in all measurements of contractility, usually within 24 to 48 hours. Of the remaining children, one showed no echocardiographic changes and subsequently died. Another child made a slow improvement over several weeks. We conclude that myocardial toxicity is a common and serious complication of scorpion stings in children. Systolic function appears to be affected predominantly. Serial echocardiography is useful to follow changes in left ventricular function, which are generally matched by clinical improvement. Patients who fail to improve within 24 to 48 hours require particularly close observation.     

Gastrointestinal manifestations in severe scorpion envenomation

OBJECTIVES: To evaluate the type and incidence of gastrointestinal manifestations secondary to scorpion envenomation and their prognostic significance. PATIENTS AND METHODS: All patients admitted to our ICU for scorpion envenomation were included in this retrospective chart review of a 13-year period (1990 - 2002). RESULTS: During the study period, 951 patients were admitted for scorpion envenomation and 72 (7.6%) died. Ages ranged from 0.5 to 90 years with a mean of 14.7 +/- 17.4 years. Gastrointestinal symptoms were present in 700 patients (73.6%): nausea in 24 (2.5%), vomiting in 687 (72.2%) and diarrhea in 41 patients (4.3%). At univariate analysis, the presence of diarrhea was associated with a fatal outcome (P < 0.05). Diarrhea was also correlated with other indicators of severe envenomation and poor prognosis: respiratory failure (P = 0.01), neurological failure (P < 0.0001), liver failure (P < 0.0001) and low blood pressure requiring catecholamine support (P = 0.02). The multivariate analysis showed that young age (age less than 5 years), fever > 38.5 degrees C, neurological failure and pulmonary edema were independent factors of severity. Digestive disorders were more frequent in children and in this subgroup diarrhea appeared to be associated with poor outcome. In a subset of patients for whom data were available, fatal cases demonstrated significantly higher liver enzymes levels on admission. CONCLUSION: In Tunisia, gastrointestinal symptoms are often observed in severe scorpion envenomations, especially in young patients. In children, diarrhea and elevated liver enzymes are associated with poor prognosis.     

Haemodynamic patterns in patients with scorpion envenomation

Objective—To study cardiovascular haemodynamics following scorpion envenomation.
Setting—Intensive care unit of a university hospital.
Patients—Eight patients with Indian red scorpion (Mesobuthus tamulus) stings.
Intervention—Captopril (6.25 to 12.5 mg orally) every 30 minutes until pulmonary oedema resolved.
Main outcome measures—Haemodynamic data obtained by pulmonary artery catheterisation.
Results—Two haemodynamic patterns were seen. There was a predominant vascular effect in one patient, with severe hypertension, tachycardia, increased systemic vascular resistance index (SVRI = 5893 dyn.s.cm^-5), and normal cardiac index (2.73 l/m²). A predominant myocardial effect with left ventricular dysfunction and normal right ventricular function was seen in the other seven patients, with tachycardia, pulmonary oedema, mild hypotension, reduced stroke volume (mean (SD), 25.9 (8.3) ml/m²), normal SVRI (1812 (831) dyn.s.cm⁻⁵), and increased pulmonary artery wedge pressure (PAWP = 25 (4.4) mm Hg). Following mild dehydration pulmonary oedema subsided (PAWP = 14 (8.5) mm Hg) in three of these patients, but hypovolaemic shock developed (right atrial pressure (RAP) = 1.3 (2.1) mm Hg); pulmonary oedema recurred with rehydration. One patient developed fatal cardiogenic shock with raised PAWP (27 mm Hg) and RAP (11 mm Hg), and vasodilatation (SVRI = 1129 dyn.s.cm⁻⁵). Stroke volume (30.5 (8.7) ml/m²) and cardiac output (4.3 (1.5) l/m²) improved with resolution of pulmonary oedema (PAWP = 14.4 (4.2) mm Hg) following afterload reduction with captopril.
Conclusions—Mild envenomation causes severe vasoconstriction and hypertension. Severe envenomation produces predominant left ventricular dysfunction with normal systemic vascular resistance manifesting as pulmonary oedema or severe hypotension depending on the fluid balance. Shock due to biventricular dysfunction and vasodilatation occurs terminally.

Keywords: scorpion sting; myocarditis; pulmonary oedema; animal toxin     

Recurrent and persistent coagulopathy following pit viper envenomation

BACKGROUND: Coagulation abnormalities following crotaline (pit viper) snakebite have traditionally been considered short-lived, but laboratory studies have rarely been reported beyond the first few days of treatment for envenomation. During the course of an antivenom clinical trial, we observed coagulation defects as late as 2 weeks following envenomation. OBJECTIVES: To document and characterize the recurrence or persistence of coagulopathy among patients envenomed by pit vipers and treated with a Fab antivenom. METHODS: Patients with moderate pit viper envenomation were enrolled in a multicenter, prospective clinical trial. A Fab-based antivenom preparation, antivenom polyvalent crotalid (ovine) Fab, was administered in all cases. Platelet count, fibrinogen level, presence of fibrin split products, prothrombin time, and partial thromboplastin time were determined before treatment and at standard intervals during the following 2 weeks. RESULTS: Of 38 patients completing the study, 20 (53%) had recurrent, persistent, or late coagulopathy 2 to 14 days after envenomation. Thrombocytopenia occurred in patients with prior thrombocytopenia; hypofibrinogenemia occurred only in those with prior hypofibrinogenemia or positive fibrin split products. No patient experienced significant spontaneous bleeding. One patient with coagulopathy developed minor bleeding following minor surgery 12 days after envenomation. CONCLUSIONS: Prolonged or recurrent coagulopathy may occur after envenomation by North American pit vipers. Patients treated with Fab-based antivenom may benefit from periodic rather than single-bolus dosing. Patients with coagulopathy should undergo close monitoring during the first 2 weeks after snakebite.     

Scorpion venom decreases lung liquid clearance in rats

It has been reported that scorpion venom causes respiratory failure and pulmonary edema. However, the effects of this toxin on lung edema clearance have not been previously studied. We examined the effects of scorpion (Tityus serrulatus) venom on the ability of the lung to clear fluid and on alveolar epithelial Na,K-ATPase. The wet-to-dry lung weight ratio was increased in anesthetized rats injected intraperitonally with scorpion venom. Lung edema clearance decreased by up to approximately 60% in rats injected with the venom. Na,K-ATPase alpha1- and beta1-subunit protein abundance and activity decreased at the basolateral membranes of alveolar epithelial type II cells incubated with scorpion venom as compared with that of control animals. There was no difference in cell injury in alveolar epithelial type II cells incubated with scorpion venom for 60 minutes compared with that of control animals. We provide here the first evidence that scorpion venom decreases lung liquid clearance, probably by downregulating Na,K-ATPase in the alveolar epithelium.     

Antithrombin III in Echis carinatus envenomation in northern Nigeria

Antithrombin III was evaluated in 21 patients admitted with Echis carinatus envenomation. Although there was evidence of incoagulability in all patients and elevated fibrin degradation products, mean antithrombin III levels were found to be significantly greater than in controls. This result suggests that Echis carinatus venom (echarin) may bypass the consumption of antithrombin III molecules.     

Cutaneous tuberculosis in Morocco.

OBJECTIVE: To describe the salient epidemiologic, clinical, histopathologic, and bacteriologic aspects of cutaneous tuberculosis in Morocco. METHODS: A retrospective review of all cases of cutaneous tuberculosis at our hospital from January 1981 through December 2004. RESULTS: Two-hundred and sixteen cases of cutaneous tuberculosis were identified and included. Men and women were equally affected. The mean patient age was 29 years. Major clinical types of cutaneous tuberculosis were scrofuloderma and gumma (72%), lupus vulgaris (12%), tuberculosis verrucosa cutis (7%), tuberculids (6%), orificial tuberculosis (1%), and tuberculous chancre (1%). Systemic involvement was seen in 35%. Where performed (66%), 81% of subjects had positive Mantoux skin tests. Lesion biopsy for histopathologic study was performed in 81% of patients and showed classical tuberculous findings in 57%. Mycobacterium tuberculosis was isolated in culture from 9% of patients. CONCLUSION: Cutaneous tuberculosis is still a common disease in Morocco, and scrofuloderma and gumma are the most common clinical presentations.     

Cardiac dysfunction and pulmonary edema following scorpion envenomation

Cardiac dysfunction with pulmonary edema following scorpion envenomation (SE) has been documented only in a few isolated case reports. We conducted a systematic hemodynamic study in five consecutive patients (mean age, 21.6 +/- 8 years) presenting with pulmonary edema occurring a few hours (9.6 +/- 5.2 hours) after SE. All patients had increased pulmonary capillary wedge pressure (mean, 25 +/- 1.8 mm Hg) while the systemic vascular resistance was elevated only in one. The stroke volume index was markedly depressed (21.7 +/- 3.6 ml/sq m) whereas cardiac index was normal or slightly decreased (2.5 +/- 0.4 L/min/sq m). Cerebral infarct and sudden cardiac arrest were the cause of death in two patients. In the three survivors, all the hemodynamic disturbances and respiratory abnormalities disappeared within a few days. We conclude that cardiac dysfunction was found in all five patients and this was reversible in the three surviving the acute episode.     

Prevalence of obesity in Morocco

Data on measured heights and weights indicate that the prevalence of obesity has increased among Moroccan population over the past 15 years. In 1984/1985, 4.1% of the adult population was obese, and the prevalence increased to 10.3% in 1998/1999. In the most recent survey in the year 2000, 13.3% of individuals aged 20 years and more were obese (22% among women and 8% among men). Excessive weight is more prevalent in urban than in rural areas, varies by geographical residence, positively associated with age and negatively with education level. The increasing prevalence of obesity poses challenges for researchers and policy makers.