Differential diagnosis between venomous (Bothrops jararaca, Serpentes, Viperidae) and “Nonvenomous” (Philodryas olfersii, Serpentes, Dipsadidae) snakebites: is it always possible?

Bites of “nonvenomous” snakes can sometimes be mistaken for the bites of venomous snakes. As an example of this confusion, this report describes confirmed bites by Philodryas olfersii and Bothrops jararaca. In the first case, a 55-y-old man with a history of controlled hypertension was bitten on his right forearm by P olfersii. Physical examination revealed extensive edema, erythema, and widespread ecchymoses throughout his right upper limb. Laboratory tests indicated leukocytosis and high D-dimer levels, but normal coagulation, suggestive of a resolved recent coagulopathy. He received only supportive treatment. In the second case, a healthy 35-y-old man was bitten by B jararaca. Although the anatomic region of the bite and the results of physical examination were similar to those in the first case, laboratory tests showed mild coagulopathy, leukocytosis, and high D-dimer levels. The patient was treated with antivenom. In both cases, the 20-min whole blood clotting test results were normal. Patients bitten by P olfersii may present with local symptoms resembling B jararaca envenomation. Without snake identification and the detection of venom-induced consumption coagulopathy, especially in places where the 20-min whole blood clotting test is the only clotting test available, it is almost impossible to establish an accurate and safe differential diagnosis. In this context, the best alternative is to take the risk of prescribing antivenom for a possible P olfersii bite rather than failing to do so for a real Bothrops bite. Late treatment for Bothrops bite can result in severe complications and sequelae.

Bites by Xenodon merremii (Wagler, 1824) and Xenodon neuwiedii (Günther, 1863) (Dipsadidae: Xenodontini) in São Paulo, Brazil: a retrospective observational study of 163 cases

Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about their medical significance. Here, we describe the clinical, epidemiological, and biological aspects of bites by two colubroid species. We retrospectively analyzed cases of Xenodon merremii and Xenodon neuwiedii bites in which the offending snake was clearly identified. Analyses included variables related to the snake and the patient, including demographic data, clinical findings, and treatments. Of the 163 cases, 123 were bites by X. merremii and 40 by X. neuwiedii. Most bites occurred in spring and summer, predominantly during the daytime. Most offending snakes were female. Bites by X. merremii juveniles were more frequent in autumn than in other seasons, whereas those by X. neuwiedii adults were in the summer. Hands and feet were the most frequently affected regions, with no significant difference between upper and lower limbs bitten by either X. merremii or X. neuwiedii. The main clinical findings were pain, transitory bleeding, erythema, and local edema. Local edema was proportionally more frequent with X. neuwiedii bites than with X. merremii bites. No patient had extensive edema or systemic envenomation. A significant association between the snout-vent-length and transitory bleeding in bites by X. merremii, but not in those by X. neuwiedii, was identified. Whole blood clotting tests were normal in all tested patients (62 cases). Sixteen patients were incorrectly treated with anti-Bothrops antivenom. In conclusion, most accidents caused by X. merremii and X. neuwiedii present mild local symptomatology. These snakes can be mistaken for lance-headed vipers, and some bites present symptoms that resemble mild bites by Bothrops sp. Physicians should be aware of X. merremii and X. neuwiedii bites to avoid unnecessary patient distress and overprescription of antivenom.

Bites by Philodryas olfersii (Lichtenstein, 1823) and Philodryas aestiva (Duméril, Bibron and Duméril, 1854) (serpentes, dipsadidae) in São Paulo, Brazil: a retrospective observational study of 155 cases

Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about the medical significance of the majority these species. Herein, we described bites by two green racer species of colubroid snakes, with respect to clinical, epidemiological, and biological features. We retrospectively analyzed proven cases of Philodryas olfersii and Philodryas aestiva bites. Only cases in which the causative animal was brought and identified by an expert were included. Analysis included variables related to the snake, patient demographics, clinical findings, whole blood clotting time (WBCT20), and treatments. Total 155 medical records were analyzed, of which 141 and 14 patients each were bitten by P. olfersii and P. aestiva, respectively. Most bites occurred in spring and summer seasons, predominantly during daytime. Most snakes were female and adult. Bites by P. olfersii adults were more frequent in summer (p < 0.001) and spring (p < 0.001). The hands were most frequently bitten by P. olfersii (59.6%), while the feet and legs (71.4%) were most bitten by P. aestiva. The most common local signs or symptoms observed were pain, edema, erythema, and transitory local bleeding. Severe pain, extensive edema, ecchymosis, and paresthesia were present only in patients bitten by P. olfersii. Significant association was observed between local bleeding and adult snakes (p = 0.019), as well as between the snout-vent-length and pain (p = 0.018), extensive edema (p = 0.024), and erythema (p = 0.047). WBCT20 was normal in the 35 cases in which it was available. Two patients were wrongly treated with anti-Bothrops antivenom. These results indicated that most accidents caused by P. olfersii and P. aestiva present mild local symptomatology. Some bites of P. olfersii bites may present local symptoms, resembling bites by Bothrops-like snakes. Physicians should be informed about these kinds of accidents, to avoid unnecessary distress to the patient and over prescription of antivenom.

Bites by Tomodon dorsatus (serpentes, dipsadidae): Clinical and epidemiological study of 86 cases.

A total of 86 proven cases of Tomodon dorsatus bites admitted to Hospital Vital Brazil (HVB) of Butantan Institute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included were those in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it was possible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86 could be studied because of their preservation status. The length of snakes (snout-vent length) ranged from 180 to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%). Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day (n = 61, 72.6%), between 9 a.m. and 3 p.m. The mean (±standard deviation) age of the victims was 26.9 ±â€¯17.2 years, and 60 (69.8%) were men. Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%) and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54, 62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), erythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%). Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mild headache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test was performed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment was offered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and analgesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated with Bothrops antivenom before their admission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis was benign. Therefore, although T. dorsatus bites can cause mild local symptomatology, it is important that health professionals know how to make the correct diagnosis to avoid unnecessary use of antivenom.

Use of infrared thermography in a case of systemic envenomation by the coral snake Micrurus frontalis (Duméril et al., 1854) in Sao Paulo, Brazil.

Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom.

Use of infrared thermography in a case of systemic envenomation by the coral snake Micrurus frontalis (Duméril et al., 1854) in Sao Paulo, Brazil

Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom.

Bites by Tomodon dorsatus (serpentes, dipsadidae): clinical and epidemiological study of 86 cases

A total of 86 proven cases ofTomodon dorsatusbites admitted to Hospital Vital Brazil (HVB) of ButantanInstitute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included werethose in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it waspossible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86could be studied because of their preservation status. The length of snakes (snout–vent length) ranged from 180to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%).Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day(n = 61, 72.6%), between 9A.M. and 3P.M. The mean ( ± standard deviation) age of the victims was 26.9 ± 17.2 years, and 60 (69.8%) were men.Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%)and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54,62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), er-ythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%).Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mildheadache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test wasperformed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment wasoffered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and an-algesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated withBothropsantivenom before theiradmission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis wasbenign. Therefore, althoughT. dorsatusbites can cause mild local symptomatology, it is important that healthprofessionals know how to make the correct diagnosis to avoid unnecessary use of antivenom.

Use of infrared thermography in a case of systemic envenomation by the coral snake Micrurus frontalis (Duméril et al., 1854) in Sao Paulo, Brazil

Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom.

Use of infrared thermography in a case of systemic envenomation by the coral snake Micrurus frontalis (Duméril et al., 1854) in Sao Paulo, Brazil

Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom.

Bites by Tomodon dorsatus (serpentes, dipsadidae): clinical and epidemiological study of 86 cases

A total of 86 proven cases ofTomodon dorsatusbites admitted to Hospital Vital Brazil (HVB) of ButantanInstitute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included werethose in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it waspossible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86could be studied because of their preservation status. The length of snakes (snout–vent length) ranged from 180to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%).Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day(n = 61, 72.6%), between 9A.M. and 3P.M. The mean ( ± standard deviation) age of the victims was 26.9 ± 17.2 years, and 60 (69.8%) were men.Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%)and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54,62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), er-ythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%).Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mildheadache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test wasperformed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment wasoffered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and an-algesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated withBothropsantivenom before theiradmission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis wasbenign. Therefore, althoughT. dorsatusbites can cause mild local symptomatology, it is important that healthprofessionals know how to make the correct diagnosis to avoid unnecessary use of antivenom.

Infrared thermography to diagnose and manage venomous animal bites and stings.

INTRODUCTION: Infrared imaging (IR) is a noninvasive technique that quantifies body surface temperature, producing a digital color image. IR has been used to study diseases in which skin temperature can reflect the presence of inflammation. METHODS: This was an observational pilot study of eight patients envenomed by snakes, spiders, and scorpions. All patients were examined using a thermal camera. RESULTS: In all cases, we obtained infrared images that corroborated clinical findings indicating localized effects of venom, specifically inflammation. CONCLUSIONS: IR has potential for use as a research, diagnostic, and monitoring tool for localized effects of animal venoms.

Infrared thermography to diagnose and manage venomous animal bites and stings

Abstract INTRODUCTION Infrared imaging (IR) is a noninvasive technique that quantifies body surface temperature, producing a digital color image. IR has been used to study diseases in which skin temperature can reflect the presence of inflammation. METHODS This was an observational pilot study of eight patients envenomed by snakes, spiders, and scorpions. All patients were examined using a thermal camera. RESULTS In all cases, we obtained infrared images that corroborated clinical findings indicating localized effects of venom, specifically inflammation. CONCLUSIONS IR has potential for use as a research, diagnostic, and monitoring tool for localized effects of animal venoms.

Infrared thermography to diagnose and manage venomous animal bites and stings

Introduction: Infrared imaging (IR) is a noninvasive technique that quantifies body surface temperature, producing a digital color image. IR has been used to study diseases in which skin temperature can reflect the presence of inflammation. Methods: This was an observational pilot study of eight patients envenomed by snakes, spiders, and scorpions. All patients were examined using a thermal camera. Results: In all cases, we obtained infrared images that corroborated clinical findings indicating localized effects of venom, specifically inflammation. Conclusions: IR has potential for use as a research, diagnostic, and monitoring tool for localized effects of animal venoms.