Study of Factors Contributing to Scorpion Envenomation in Arizona.

INTRODUCTION: Arizona has the highest incidence of scorpion envenomation reported to US poison control centers (PCCs). Most cases reported are from a residence, but specific details are limited. METHODS: Specialists at Arizona's two PCCs prospectively completed the Factors of Envenomation in Arizona Residences Survey (FEARS) for residential scorpion exposures reported during 4-week periods in the summer and winter. Based on these results, a second questionnaire, FEARS-2, targeting indoor residential exposures was then administered. RESULTS: Among 382 FEARS responses, no significant differences were found between summer and winter exposures, except for rainfall in the previous 24 hours. Scorpions had previously been seen in 81.8% of exposures, and 29.4% reported a previous envenomation at the residence. Most exposures occurred indoors (86.5%) and in a bedroom (42.5%), where the scorpion was in the bed in 54.7% of cases. Among all stings in a bed, 72.7% occurred while sleeping. Children were stung more often in a family room (38.6% vs. 14.5%; p < .00001) and by a scorpion on the floor (53.5% vs. 35.0%; p = .0014). Distal extremities were stung most often, particularly the foot (34.5%), with most being while barefoot (81.9%). CONCLUSION: A variety of characteristics and associations involving residential scorpion envenomations were identified. These details can be used to guide public education and primary prevention efforts to help decrease residential scorpion exposures.

Incidence of allergic reactions to Crotalidae polyvalent immune Fab.

CONTEXT: The administration of Crotalidae polyvalent immune Fab (FabAV) currently requires close observation, so patients can be monitored for hypersensitivity reactions. The objective of this study was to evaluate the occurrence of hypersensitivity reactions to FabAV. METHOD: This was a retrospective cohort study utilizing data from a statewide poison center database in the United States. Records of all patients envenomated by a rattlesnake and treated with FabAV between January 2002 and December 2014 were evaluated. Patients with acute hypersensitivity reactions were identified, and reactions were evaluated descriptively. RESULTS: A total of 1340 adult and pediatric patients received FabAV during the study period. Of these, 19 (1.4%) patients had a potential reaction to FabAV, with 10 requiring a reduction in infusion rate, but none requiring discontinuation of the antivenom. Reactions occurred during the loading dose (n = 10), maintenance doses (n = 4), or were delayed reactions (n = 6). Symptoms recorded included pruritus (n = 8), hives (n = 8), rash (n = 7), vomiting (n = 7), nausea (n = 6), dyspnea or wheezing (n = 4), diaphoresis (n = 3), throat irritation (n = 2), and mild hypotension (n = 2). One patient was given a concomitant administration of low dose epinephrine infusion until completion of the antivenom course. However, none of the reactions were considered to be life-threatening. CONCLUSION: FabAV appears to be associated with a low incidence of acute hypersensitivity reactions. Patients may not require placement in a location capable of detecting and rapidly responding to hemodynamic and/or airway issues for FabAV monitoring alone.

Prophylactic Antibiotics Are Not Needed Following Rattlesnake Bites.

BACKGROUND: Antibiotics are sometimes administered to victims of rattlesnake bites in the hope of preventing infections. Experts in the field recommend that prophylactic antibiotics not be used because secondary infections are rare. Current recommendations are based on a small number of studies conducted in the United States. We decided to reexamine the issue by taking advantage of a large database on snakebites in Arizona. This allowed us to determine how often prophylactic antibiotics were used and whether or not they were effective. METHODS: We obtained data from the Arizona Poison and Drug Information Center electronic medical record, Toxicall. Rattlesnake bites occurring over 18 years (1999-2016) were analyzed according to the descriptors: infection, pus, isolation of bacteria, and antibiotic use. RESULTS: There were 2748 evaluable patients identified as having rattlesnake bites. The mean number of bite victims was 153 per year. Most (72%) were male. Their ages ranged from 8 months to 91 years. Prophylactic antibiotics were administered to 120 of 2748 (4.4%) victims. There were 27 postbite infections (0.98%) but no deaths. Victims sometimes manipulated the wound sites. Microorganisms were isolated from only 9 patients. Only a Salmonella sp. was of certain reptilian origin; the others were likely of human origin. CONCLUSIONS: This large study supports recommendations that prophylactic antibiotics not be used following rattlesnake bites in the United States. The incidence of postbite infections was low, <1%. All but 1 of the bacteria isolated from the wounds were common inhabitants of human skin and not found in oral secretions of rattlesnakes.

Arizona Ridge-nosed rattlesnake envenomation: Case report of a personal encounter with the official state reptile of Arizona, Crotalus willardi willardi.

This case report describes the effects of an envenomation from one of the most infrequently encountered species of rattlesnake in the United States, Crotalus willardi willardi (C. w. willardi), the Arizona Ridge-nosed Rattlesnake. A previously healthy 57-year-old male sustained a bite to his non-dominant hand from a C. w. willardi. The most pronounced effect from the envenomation was edema and progression of edema that extended from his hand to the mid bicep. He also experienced erythema and tenderness to palpation in the affected limb, and some diminished range of motion in the hand. He expressed only minimal pain. Other than a mildly positive D-Dimer and leukocytosis, he had no significant hematologic effects and no systemic effects. He was treated with standard doses of Crotalidae Polyvalent Immune Fab (Ovine). He reported complete recovery from the envenomation within three days of the bite. Although envenomation from rattlesnakes is somewhat common in Arizona, knowing the exact species of snake is not. Confirmed documentation is exceedingly rare as most people do not recognize the different rattlesnake species. In addition, some species of rattlesnake (such as C. w. willardi) are especially reclusive and found only in isolated mountainous regions. Being able to confirm an envenomation by C. w. willardi would require not only someone knowledgeable in herpetology, but also, preferably, photographic evidence. This case has both.

Centruroides sculpturatus envenomation in three adult patients requiring treatment with antivenom.

CONTEXT: Envenomation by Centruroides sculpturatus can manifest with cranial nerve dysfunction and neuromuscular hyperactivity. While these symptoms are most commonly seen in young children, they may also be seen in adults. CASE DETAILS: Three cases of adult patients are presented with grades III & IV scorpion envenomation. They reported symptoms including disconjugate, roving eye movements, and motor involvement. Also reported were hyposmia, difficulty with fine motor movements, and dysgeusia. All were first treated with benzodiazepines with little to no effect. They then received a three vial antivenom bolus with resolution of severe symptoms within 30-60 min. DISCUSSION: Severe Centruroides envenomation can occur in adults as well as children. These three cases demonstrate the usefulness, safety, and effectiveness of antivenom therapy to quickly relieve symptoms in adult patients with grades III & IV envenomations.

Kissing Bug (Triatoma spp.) Intrusion into Homes: Troublesome Bites and Domiciliation.

Kissing bugs (Triatoma spp.) frequently enter homes and bite human and pet occupants. Bites may lead to severe allergic reactions and, in some cases, death. Kissing bugs are also vectors of Trypanosoma cruzi, the cause of Chagas disease. In general, modern houses in the United States are not conducive to domiciliation of kissing bugs (bugs living out their entire life within the home with the presence of eggs, nymphs, adults, and exuviae). Construction features such as concrete foundations, solid walls and ceilings, window screens, tight thresholds for doors and windows, and other measures impede bug entry into homes, and air conditioning reduces the need for open doors and windows. Where Chagas disease is endemic in Mexico and Central and South America, homes often have thatch roofs, adobe walls, and open doors and windows. We investigated numerous instances of kissing bug intrusions into homes in Southern Arizona, California, and Louisiana and documented the reactions to kissing bug bites. Our work confirms the importance of modern home construction in limiting kissing bug intrusions. Older homes, especially those lacking modern screening, caulking, and weather stripping to reduce air leakage, may be subject to kissing bug intrusions and domiciliation. We describe a community in Southern Arizona where domiciliation of homes by Triatoma recurva is common. We also provide recent data regarding kissing bug bites and allergic reactions to the bites.

Differential physiological and behavioral cues observed in individuals smoking botanical marijuana versus synthetic cannabinoid drugs.

CONTEXT: Synthetic cannabinoid use has increased in many states, and medicinal and/or recreational marijuana use has been legalized in some states. These changes present challenges to law enforcement drug recognition experts (DREs) who determine whether drivers are impaired by synthetic cannabinoids or marijuana, as well as to clinical toxicologists who care for patients with complications from synthetic cannabinoids and marijuana. Our goal was to compare what effects synthetic cannabinoids and marijuana had on performance and behavior, including driving impairment, by reviewing records generated by law enforcement DREs who evaluated motorists arrested for impaired driving. METHODS: Data were from a retrospective, convenience sample of de-identified arrest reports from impaired drivers suspected of using synthetic cannabinoids (n = 100) or marijuana (n = 33). Inclusion criteria were arrested drivers who admitted to using either synthetic cannabinoids or marijuana, or who possessed either synthetic cannabinoids or marijuana; who also had a DRE evaluation at the scene; and whose blood screens were negative for alcohol and other drugs. Exclusion criteria were impaired drivers arrested with other intoxicants found in their drug or alcohol blood screens. Blood samples were analyzed for 20 popular synthetic cannabinoids by using liquid chromatography-tandem mass spectrometry. Delta-9-tetrahydrocannabinol (THC) and THC-COOH were quantified by gas chromatography-mass spectrometry. Statistical significance was determined by using Fisher's exact test or Student's t-test, where appropriate, to compare the frequency of characteristics of those in the synthetic cannabinoid group versus those in the marijuana group. RESULTS: 16 synthetic cannabinoid and 25 marijuana records met selection criteria; the drivers of these records were arrested for moving violations. Median age for the synthetic cannabinoid group (n = 16, 15 males) was 20 years (IQR 19-23 years). Median age for the marijuana group (n = 25, 21 males) was 20 years (IQR 19-24 years) (p = 0.46). In the synthetic cannabinoid group, 94% (15/16) admitted to using synthetic cannabinoids. In the marijuana group, 96% (24/25) admitted to using marijuana. Blood was available for testing in 96% (24/25) of the marijuana group; 21 of these 24 had quantitative levels of THC (mean + SD = 10.7 + 5 ng/mL) and THC-COOH (mean + SD = 57.8 + 3 ng/mL). Blood was available for testing in 63% (10/16) of the synthetic cannabinoid group, with 80% (8/10) of these positive for synthetic cannabinoids. Those in the synthetic cannabinoid group were more frequently confused (7/16 [44%] vs. 0/25 [0%], p ≤ 0.003) and disoriented (5/16 [31%] vs. 0/25 [0%], p ≤ 0.003), and more frequently had incoherent, slurred speech (10/16 [63%] vs. 3/25 [12%], p = 0.0014) and horizontal gaze nystagmus (8/16 [50%] vs. 3/25 [12%], p = 0.01) than those in the marijuana group. CONCLUSION: Drivers under the influence of synthetic cannabinoids were more frequently impaired with confusion, disorientation, and incoherent, slurred speech than drivers under the influence of marijuana in this population evaluated by DREs.

Gila monster (Heloderma suspectum) envenomation: Descriptive analysis of calls to United States Poison Centers with focus on Arizona cases.

BACKGROUND: The Gila monster (Heloderma suspectum) is a venomous lizard native to the deserts of southwestern United States (US) and northern Mexico. The purpose of this study was to describe human exposures to Gila monsters reported to US poison control centers (PCCs) with a focus on Arizona cases. METHODS: The American Association of Poison Control Centers' National Poison Data System (NPDS) was used to access and retrospectively review all calls to US PCCs, concerning Gila monsters between January 1, 2000 and October 31, 2011. In addition, detailed records from the two Arizona PCCs were reviewed for the same time period. RESULTS: A total of 319 calls regarding Gila monsters were identified in the NPDS. Of these, 105 (33%) were human exposures; most (79%) occurred in males. A total of 71 (68%) of these 105 cases were referred to a health care facility (HCF); 30 (29%) were managed on-site. Of the 71 HCF referrals, 36 (51%) were discharged home and 17 (24%) were admitted. Most (65%) admissions were to an intensive care unit (ICU). Arizona's PCCs received 70 unique reports of Gila monster bite. Most (77%) of the bites in Arizona involved an upper extremity. Eight (11%) involved patients under the age of 18 years. Eleven (16%) Arizona cases were work-related. Twenty-eight (40%) of the 70 bites in Arizona were evaluated in a HCF, but not admitted. Eleven (16%) were admitted, of which five were to an ICU. Six patients had edema of airway structures; three required emergent airway management, one by cricothyrotomy. There were no deaths. CONCLUSION: Gila monster bites are uncommon. Many cases did not require hospitalization. Edema of airway structures is an infrequent, but life-threatening complication.

Fatal gastrointestinal hemorrhage after a single dose of dabigatran.

INTRODUCTION: Dabigatran (Pradaxa) is a new oral anticoagulant approved by the Food and Drug Administration (FDA), available internationally and indicated as an alternative to warfarin for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. Dabigatran does not require laboratory monitoring and its kinetics allow for a more rapid onset of action with a time to peak concentration of 1.25-1.5 h. We are reporting a fatality resulting from gastrointestinal bleeding after the ingestion of a single dose of dabigatran 150 mg. CASE DETAILS: A 92-year-old man with a medical history of chronic obstructive pulmonary disease, hypothyroidism, and atrial flutter presented to the emergency department with complaints of weakness and rectal bleeding. He was seen by his Cardiologist the day before and was found to be in new atrial fibrillation. He was prescribed dabigatran 150 mg twice daily for anticoagulation therapy. He took one dose of dabigatran 150 mg at 2200 and woke up the following morning before 0900 with profuse rectal bleeding. The initial vital signs in the emergency department, approximately 11 h after ingestion, were heart rate 72 beats/min, blood pressure 62/30 mmHg, and lab work showed hemoglobin 9.9 g/dL, international normalization ratio (INR) 1.99, blood urea nitrogen (BUN) 66 mg/dL, and creatinine (SCr) 1.4 mg/dL (creatinine clearance (CrCl) 24.2 mL/min). He was resuscitated with intravenous fluids, two units of packed red blood cells, two units of fresh frozen plasma, platelets, and vitamin K 10 mg intravenously. He was also given an unknown dose of erythromycin early in his hospital stay. An actively bleeding gastric ulcer was discovered and treated with local epinephrine injections. Approximately 48 h after his exposure, he received an additional two units of blood to treat his decreasing blood pressure (98/41 mmHg). On day three, his hemoglobin and hematocrit were stable at 10 g/dL and 30%, INR 1.6, he was extubated and off vasoactive medications. Day six of hospitalization, he began having maroon stools, his hemoglobin decreased to 8.1 g/dL and his platelets to 81 × 1000/mcL. On day seven, the hemoglobin decreased to 6.4 mg/dL. Despite aggressive resuscitative efforts and supportive care, he died. DISCUSSION: This case demonstrates the potential of a single dose of dabigatran 150 mg to result in a fatal gastrointestinal hemorrhage. This patient was started on the maximum dose with a CrCl 33.9 mL/min and on admission CrCl 24.2 mL/min, suggesting underlying renal insufficiency.

Venom variability and envenoming severity outcomes of the Crotalus scutulatus scutulatus (Mojave rattlesnake) from Southern Arizona.

Twenty-one Mojave rattlesnakes, Crotalus scutulatus scutulatus (C. s. scutulatus), were collected from Arizona and New Mexico U.S.A. Venom proteome of each specimen was analyzed using reverse-phase HPLC and SDS-PAGE. The toxicity of venoms was analyzed using lethal dose 50 (LD(50)). Health severity outcomes between two Arizona counties U.S.A., Pima and Cochise, were determined by retrospective chart review of the Arizona Poison and Drug Information Center (APDIC) database between the years of 2002 and 2009. Six phenotypes (A-F) were identified based on three venom protein families; Mojave toxin, snake venom metalloproteinases PI and PIII (SVMP), and myotoxin-A. Venom changed geographically from SVMP-rich to Mojave toxin-rich phenotypes as you move from south central to southeastern Arizona. Phenotypes containing myotoxin-A were only found in the transitional zone between the SVMP and Mojave toxin phenotypes. Venom samples containing the largest amounts of SVMP or Mojave toxin had the highest and lowest LD(50s), respectively. There was a significant difference when comparing the presence of neurotoxic effects between Pima and Cochise counties (p=0.001). No significant difference was found when comparing severity (p=0.32), number of antivenom vials administered (p=0.17), days spent in a health care facility (p=0.23) or envenomation per 100,000 population (p=0.06). Although not part of the original data to be collected, death and intubations, were also noted. There is a 10× increased risk of death and a 50× increased risk of intubations if envenomated in Cochise County.

Toxicologic information resources for reptile envenomations.

The United States is the largest importer of reptiles in the world, with an estimated 1.5 to 2.0 million households keeping one or more reptiles. Snakes account for about 11% of these imports and it has been estimated that as many as 9% of these reptiles are venomous. Envenomations by nonindigenous venomous species are a rare but often serious medical emergency. Bites may occur during the care and handling of legitimate collections found in universities, zoos, or museums. The other predominant source of exotic envenomation is from amateur collectors participating in importation, propagation, and trade of non-native species. This article provides toxicologic information resources for snake envenomations.