**3. Snake identification**

124 Complementary Pediatrics

higher incidence in men (2.5:1) but also a reasonably high incidence in pediatric population between the ages of 11 and 16 (39.3%), followed closely by even younger children ages of 6- 10 (32.1%). This may be related to the fact that in several under-developed tropical countries where snakebites represent a major health issue children take part in agricultural activities or are attacked due to their innate curiosity, which in turn, makes them victims more easily than adults. Snake bites remain a public health problem in most countries. This is especially true in countries where agricultural activities are predominant, since this is one of the occupations more often affected by snakebites (Chippaux, 1998). Once we get hold of he few statistics we have, we face a new problem: the disparity in the epidemiological data. This reflects different grades of reporting. The more industrialized the country, the more reliable the statistics are. Sadly, snake bites are a problem related to low-income countries that have frail health systems and a lower rate of reporting. Also, morbidity and mortality have low rates and are well documented in first-world countries, probably because of the health facilities and availability of newer and better treatments. This is yet another argument to sustain that snake envenoming is a disease of the underdeveloped countries. In the few studies we can relate to, a negative association between snakebite deaths and government expenditure on health services has been found. Because of this, mortality is highest in these countries, since the population has no access to proper and adequate treatment and the government is not able to provide it because they are just not capable of dealing with the financial burden of snakebites (Harrison, Hargreaves, Wagstaff, Faragher, & Lalloo, 2009). In México, an average of 20 deaths per year are reported. However, very few accidents are reported in communities most at risk. These communities also have little access to health services. In fact, about 27 000 cases of snake envenomation and more than 100 deaths per year occur in México. Between 1994 and 1996, the Mexican Social Security Institute (IMSS) reported 1 961 venomous snake bites; thirty percent of patients were children. In the IMSS report, the age group most affected was 15 to 44 years, with 51.4% of cases. The immense majority of poisonings occurred between June and October and 70-90% of these bites were

**Area of the Body** 

Foot and Ankle 72 Thigh 14 Hand 13 Head 10

For years, it has been accepted that snake attacks occur in the field and men are the most affected, but in the study by Sotelo-Cruz it was found that there is no predominance in gender and while it is true that most of the children attacked were from rural areas, these attacks occured nearby their living places in some cases even within their home. The seasons of the year when more attacks were reported were summer and autumn. This is because the summer season in these countries lasts nearly six months. The time of day when most of the attacks happened ranges from 2:00 and 7:00 p.m., although 12.7% of the attacks happened during the night, the injury site was located in the legs in 78.1% of cases (Sotelo 2004).

**Frequency (%)** 

**Involved** 

Table 1. Areas most commonly involved in snakebites.

located in the legs.

In the world there are over 2,500 snake species described, of these, only about 350 are considered poisonous and dangerous for humans. These 2,500 snake species are divided into 15 families and the following have enough species to be relevant or dangerous (Government of Canada, n.d.): Colubridae, Boidae, Viperidae, and Elapidae or Hydrophiidae. Just as we have countries where venemous snakes are a major health issue because of the large number of species they harbor, we also have countries where venemous snakes are virtually non-existent (except for imported snakes), such as New Zealand, Cuba, Haiti, Jamaica, Puerto Rico, Ireland, Polynesia, Hawaii and the polar regions.

In this chapter, we are going to be focusing on the snakes most commonly found in the Americas, more specifically in North America (the United States and Northern México), These snakes are from the Elapidae and the Viperidae families such as the pit viper, the rattlesnake, the water moccasin, and the copperhead, since they are responsible for about 99% of the cases reported. The coral snake, which can also be found in North America, is responsible for only 1% of the cases, along with the exotic imported species.

Fig. 1. Diagram that shows the fifteen families of snakes in the world. The families marked in red contain the most important and dangerous snakes in America.

A very important part of the process of providing the best medical care available resides in the identification of the snake. Important as this is, it is recommended not to go after the snake to try to identify it or kill it. We need to remember that most snakes only attack when they feel menaced in the first place, thus, going after a snake after it has already attacked would put us in more danger, risking a second bite or a first bite in a different person. If we are in an advantageous situation (adequate lighting, such as broad sunlight, regular, flat

Snake Bites in Pediatric Patients, a Current View 127

it is seldom a serious threat to life or limb. Copperheads are usually 60 cm to 1 m in length and have a light pink to red–brown body with darker brown crossbands shaped like

The water moccasin, also known as the cottonmouth (Agkistrodon piscivorus), is a semiaquatic pit viper found in the Southeastern of the United States, including Southeast Virginia, West and Central Alabama, South Georgia, Illinois, East and central Kentucky, South and Central Oklahoma, Texas, North Carolina, South Carolina and Florida. These are larger and more belligerent snakes, often traveling with their heads in an aggressive 45 degree angle from the horizontal. Their body is olive brown to black, with darker markings on the sides that often fade over the dorsum. The ventral surface is lighter in color. The oral mucosa is distinctively white, hence the name cottonmouth. Like the copperhead, bites from this species are, in general, less serious than Crotalus species (Hodge III & Tecklenburg, 2006). The cottonmouth may alert the future victim of the imminent attack by mouth gaping

Coral snakes belong to the Elapidae family. This is a relatively shy and passive snake. It can be found in Southeast United States as far as west Texas, as well as in countries from Central and South America. Unlike the pit viper, coral snakes have round pupils, not so triangular heads and do not have pits with heat sensing organs between the eye and the nostril. They can measure approximately 60 cm. and are described as a brightly colored snake. They can attract young children, who end up being victims of this venomous snake. It can be easily confused with non-poisonous snakes because of their bright colors. If the snake is presented in a safe way we can observe red and black bands that alternate with narrow yellow rings. Whenever we see yellow rings next to red bands we should think of a coral snake. Nonpoisonous similar snakes have yellow rings directly in touch with black (and not red) bands.

In Europe, Africa and Oceania, we have an enormous number of species as dangerous as the ones living in America. In Europe, the Common adder is distributed widely across the continent, even reaching the northern part of Morocco. Has a variable color, ranging from completely black specimens to different dark zigzag patterns, measuring around 45 centimeters. Inoculates hemotoxic venom, its victims usually are campers, hikers and field workers. Another hemotoxic venom inoculating snake in Europe, although not as common (found only in Italy, Yugoslavia, northern Albania, and Romania) is the Long-nosed adder, which is gray, brown, or reddish with a dark brown or black zigzag pattern running the length of its back. A dark stripe is usually found behind each eye. In the southeast Europe

Regarding Africa, the Boomslang a 60-centimeter green or brown snake with hemotoxic venom inhabits the sub-Saharan Africa. Through most of the African territory particularly Angola, Cameroon, Uganda, Kenya, and the Congo we can find the Bush viper, often called

area we can find the Pallas' viper with hemotoxic venom that is rarely fatal.

hourglasses. The head has a coppery tinge (Hodge III & Tecklenburg, 2006).

**3.1.3 Water moccasin** 

**3.2 Coral snake** 

**3.3 Snakes outside america** 

and tail vibrations (Glaudas & Winne, 2007).

surface with minimal plant growth, etc.) there are several bits of information we should recall if we clearly see the snake:

### **3.1 Pit viper**

These snakes have pits, one in each side of the face, located between the eye and the nostril. These pits, not found in the non-venomous species, contain heat-sensing organs, very important for these venomous snakes, since they have a very poor vision. If we have a good view of the snake, we can observe its pupils, which are different from non-poisonous snakes. Pupils in the pit viper are elliptical and vertically oriented. The fangs in venomous snakes are only superior, two in number and hollow. These are usually 5 to 20 mm long. These fangs are folded posteriorly in the palate and are shown only when the snake attacks. Regarding the head, in most poisonous snakes it is more triangular than in non-poisonous snakes. Last, if the snake is captured or killed, we can examine the anal plate. In poisonous snakes the scales are in a single row after the anal plate. In non-harmful snakes the anal plate ends in a cleft or a double row of scales. These snakes produce an hemotoxic venom.

#### **3.1.1 Rattlesnakes**

There are four kinds of rattlesnakes (Crotalus) in North America, this is the reason why this species is very heterogeneous regarding its colors and length. We have: the Eastern Diamondback, the Western Diamondback, the Mojave Rattlesnake and the Tropical Rattlesnake. The Eastern Diamondback is the most common. We can find it in the Southeast Coastal area of the United States (North Carolina, South Carolina, Louisiana and Florida). This snake can be up to two meters long and has a characteristic pattern of bright lines that form a symmetric diamond pattern. The Western Diamondback lives in the Southeast of the United States, mainly southeast California, Oklahoma, Arizona, New Mexico and Texas. It is a little shorter than the Eastern Diamondback measuring only up to 1.5 meters. The Mojave Rattlesnake can be found in the Southwestern United States, principally in the Mojave Desert in California, Nevada, Southeast Arizona, Texas and the north portion of Mexico. It prefers rocky desert areas and this species is only about 75 cm. Last, we have the Tropical Rattlesnake, which lives in crops and sandy areas in the Southern of Mexico, Central America and South America (except Chile). These can measure up to two meters long, even though it usually is 1.5 meters long. These snakes are responsible for approximately 60% of all pit viper attacks and for this reason emergency staff need to be familiar with the general characteristics of these snakes and always take into consideration the possibility of a rattlesnake attack when treating a patient that has been bitten by an unidentified snake in the United States and Northern Mexico (Hodge III & Tecklenburg, 2006). Rattlesnakes attract children because of the sound the rattle makes when the snake is ready to attack.

#### **3.1.2 Copperheads**

The copperhead (Agkistrodon contortrix) is a common poisonous snake that lives in the Southeast United States (from Florida to Massachusetts) and much of the Northeast (Oklahoma, Illinois, Kansas, Ohio) but it can reach westward to states such as Texas and Nebraska. This reptile accounts for approximately 30% of venomous snake bites but, luckily, it is seldom a serious threat to life or limb. Copperheads are usually 60 cm to 1 m in length and have a light pink to red–brown body with darker brown crossbands shaped like hourglasses. The head has a coppery tinge (Hodge III & Tecklenburg, 2006).

#### **3.1.3 Water moccasin**

126 Complementary Pediatrics

surface with minimal plant growth, etc.) there are several bits of information we should

These snakes have pits, one in each side of the face, located between the eye and the nostril. These pits, not found in the non-venomous species, contain heat-sensing organs, very important for these venomous snakes, since they have a very poor vision. If we have a good view of the snake, we can observe its pupils, which are different from non-poisonous snakes. Pupils in the pit viper are elliptical and vertically oriented. The fangs in venomous snakes are only superior, two in number and hollow. These are usually 5 to 20 mm long. These fangs are folded posteriorly in the palate and are shown only when the snake attacks. Regarding the head, in most poisonous snakes it is more triangular than in non-poisonous snakes. Last, if the snake is captured or killed, we can examine the anal plate. In poisonous snakes the scales are in a single row after the anal plate. In non-harmful snakes the anal plate ends in a cleft or a double row of scales. These snakes produce an hemotoxic venom.

There are four kinds of rattlesnakes (Crotalus) in North America, this is the reason why this species is very heterogeneous regarding its colors and length. We have: the Eastern Diamondback, the Western Diamondback, the Mojave Rattlesnake and the Tropical Rattlesnake. The Eastern Diamondback is the most common. We can find it in the Southeast Coastal area of the United States (North Carolina, South Carolina, Louisiana and Florida). This snake can be up to two meters long and has a characteristic pattern of bright lines that form a symmetric diamond pattern. The Western Diamondback lives in the Southeast of the United States, mainly southeast California, Oklahoma, Arizona, New Mexico and Texas. It is a little shorter than the Eastern Diamondback measuring only up to 1.5 meters. The Mojave Rattlesnake can be found in the Southwestern United States, principally in the Mojave Desert in California, Nevada, Southeast Arizona, Texas and the north portion of Mexico. It prefers rocky desert areas and this species is only about 75 cm. Last, we have the Tropical Rattlesnake, which lives in crops and sandy areas in the Southern of Mexico, Central America and South America (except Chile). These can measure up to two meters long, even though it usually is 1.5 meters long. These snakes are responsible for approximately 60% of all pit viper attacks and for this reason emergency staff need to be familiar with the general characteristics of these snakes and always take into consideration the possibility of a rattlesnake attack when treating a patient that has been bitten by an unidentified snake in the United States and Northern Mexico (Hodge III & Tecklenburg, 2006). Rattlesnakes attract children because of the sound the rattle makes when the snake is ready to attack.

The copperhead (Agkistrodon contortrix) is a common poisonous snake that lives in the Southeast United States (from Florida to Massachusetts) and much of the Northeast (Oklahoma, Illinois, Kansas, Ohio) but it can reach westward to states such as Texas and Nebraska. This reptile accounts for approximately 30% of venomous snake bites but, luckily,

recall if we clearly see the snake:

**3.1 Pit viper** 

**3.1.1 Rattlesnakes** 

**3.1.2 Copperheads** 

The water moccasin, also known as the cottonmouth (Agkistrodon piscivorus), is a semiaquatic pit viper found in the Southeastern of the United States, including Southeast Virginia, West and Central Alabama, South Georgia, Illinois, East and central Kentucky, South and Central Oklahoma, Texas, North Carolina, South Carolina and Florida. These are larger and more belligerent snakes, often traveling with their heads in an aggressive 45 degree angle from the horizontal. Their body is olive brown to black, with darker markings on the sides that often fade over the dorsum. The ventral surface is lighter in color. The oral mucosa is distinctively white, hence the name cottonmouth. Like the copperhead, bites from this species are, in general, less serious than Crotalus species (Hodge III & Tecklenburg, 2006). The cottonmouth may alert the future victim of the imminent attack by mouth gaping and tail vibrations (Glaudas & Winne, 2007).

#### **3.2 Coral snake**

Coral snakes belong to the Elapidae family. This is a relatively shy and passive snake. It can be found in Southeast United States as far as west Texas, as well as in countries from Central and South America. Unlike the pit viper, coral snakes have round pupils, not so triangular heads and do not have pits with heat sensing organs between the eye and the nostril. They can measure approximately 60 cm. and are described as a brightly colored snake. They can attract young children, who end up being victims of this venomous snake. It can be easily confused with non-poisonous snakes because of their bright colors. If the snake is presented in a safe way we can observe red and black bands that alternate with narrow yellow rings. Whenever we see yellow rings next to red bands we should think of a coral snake. Nonpoisonous similar snakes have yellow rings directly in touch with black (and not red) bands.

#### **3.3 Snakes outside america**

In Europe, Africa and Oceania, we have an enormous number of species as dangerous as the ones living in America. In Europe, the Common adder is distributed widely across the continent, even reaching the northern part of Morocco. Has a variable color, ranging from completely black specimens to different dark zigzag patterns, measuring around 45 centimeters. Inoculates hemotoxic venom, its victims usually are campers, hikers and field workers. Another hemotoxic venom inoculating snake in Europe, although not as common (found only in Italy, Yugoslavia, northern Albania, and Romania) is the Long-nosed adder, which is gray, brown, or reddish with a dark brown or black zigzag pattern running the length of its back. A dark stripe is usually found behind each eye. In the southeast Europe area we can find the Pallas' viper with hemotoxic venom that is rarely fatal.

Regarding Africa, the Boomslang a 60-centimeter green or brown snake with hemotoxic venom inhabits the sub-Saharan Africa. Through most of the African territory particularly Angola, Cameroon, Uganda, Kenya, and the Congo we can find the Bush viper, often called

Snake Bites in Pediatric Patients, a Current View 129

prompts the formation of fibrin monomers, generating an abnormal mesh of fibrin, upon which the factor XIII can not act being lysed by the mechanisms of fibrinolysis as degradation products of fibrin D-dimer. It also contains inhibitors of factor X activation of

We can have diverse clinical manifestations when it comes to snakebites. The inapparent bites occur mainly when dealing with non-venomous snakes or when we have a bite by a venemous snake which did not cause symptoms. Due to the low frequency of poisoning by snake bites, it has been suggested that snakes who bite as a defensive move against humans

Generally, local events occur in the time span of the first 10 to 30 minutes. Local pain is perceived along with the presence of edema, exudate and presence of bullae, accompanied by numbness of the tongue, jaw and scalp. There may be numbness around the bite with bleeding or a purpuric rash and/or necrosis or gangrene. As for the systemic manifestations, they start with the onset of fear and impending death feeling, which accelerates absorption of the venom. Other symptoms depend on the pathophysiological changes of the venom of certain species; neurotoxic venoms manifest as neuromuscular blockade resulting in flaccid paralysis, ptosis, and difficulty breathing; cardiotoxic venoms manifest as tachycardia, hypotension and ECG abnormalities, there may be fluctuations in heart rate, blood pressure and even heart failure in severe cases. There may be muscle necrosis resulting in

Different poisons trigger different clinical manifestations and it is important for healthcare staff to learn to recognize the general characteristics of every single of them or at least the

Pit viper snakes (rattlesnakes, copperheads, and water moccasins) produce hemotoxic venom. Local pain is typically intense, and a sensation of burning occurs within five to ten minutes. The pain is greater with ensuing edema and presumably increases with a larger inoculation of venom. Only in rare occasions the venom will sediment in the muscule compartment, in which cases the amount of edema will be minimal. In Diamondback rattlesnake bites, the limb may swell completely in just one hour. There can be local echymmosis and vesicles in the first hours. Lymphadenitis and some adenomegalies may become apparent. Victims of a significant rattlesnake bite often complain within minutes of perioral numbness, extending to the scalp and periphery. This parenthesis may be

These patients also may have nausea, vomiting, weakness, chills, sweating, syncope, and other more ominous symptoms of systemic venom absorption. A copperhead envenomation produces less local symptoms, and systemic consequences are often minimal or nonexistent unless a small child, multiple bites, or a larger than average snake is involved. The water

more common, depending on their geographical localization.

accompanied by a metallic taste in the mouth.

moccasin's effects are more variable.

do not inject enough venom to cause systemic symptoms, these are called dry bites.

prothrombin and thrombin and fibrinogenases.

**5. Clinical manifestations** 

myoglobinuria.

**5.1 Pit vipers** 

leaf viper because of its color and because it uses its prehensile tail to secure itself to branches. Its venom is hemotoxic and healthy adults rarely die from its bite. The feared Asiatic cobra is distributed from southeast to southwest Asia, including Indonesia. Its venom is highly neurotoxic, causing respiratory paralysis with some tissue damage. With even stronger neurotoxic venom and wider distribution (From southeast to southwest Asia, including Indonesia) we have the Egyptian cobra

#### **4. Pathophysiology**

In the pathophysiology of envenomation we can consider different factors that can be divided into human factors, which include the size of the victim, general health and wound characteristics, such as depth of fang penetration and location of the wound and snake factors which include the size of the snake, the amount of venom injected, and the strength of the particular species venom. Healthy, angered and hungry snakes unload more venom than a recently satiated and surprised snake (Hodge III and Tecklenburg 2006). Snake venom is a complex mixture of proteolytic enzymes, peptidases, proteinases, phospholipases and neurotoxins that are able to cause serious damage to the musculoskeletal, blood clotting, cardiopulmonary, renal and central nervous systems. Due to the venom, there is cell function degeneration and the final outcome depends on the type of venom injected. Generally, envenomation increases capillary permeability that results in blood and plasma loss from the intravascular to the extracellular space, creating edema, which, in case of being sufficiently important, may cause circulatory compromise and hypovolemic shock. Also, snake venom has citolytic properties, which cause local necrosis and secondary infection, which could result in sepsis and death (De la O Cavazos 2006). Venoms with neurotoxic activity produce paralysis and respiratory distress by binding the nicotinic acetylcholine receptors, and preventing the depolarizing action of acetylcholine. Hemotoxic effects induce hemolysis, fibrinogen proteolysis, and thrombocytopenia, which, along with activation of plasminogen, can lead to a bleeding diathesis in severe envenomation (Hodge III & Tecklenburg, 2006). Cardiotoxic effects lead to heart failure as well as myotoxicity and nephrotoxicity. Some are known poisons and it is important to know their mechanism of action for diagnosing anding accidents caused by these reptiles. It is also helped to unveil a number of physiological distrurbances caused by these venoms regarding neurotransmission, coagulation processes and mechanisms of inflammation. The most important effect of neurotoxins is to prevent the transmission of nerve impulses in cholinergic synapses. ALFA neurotoxins interfere with neurotransmitter release and cause muscle paralysis, respiratory failure and death by asphyxiation. Phospholipase A2 catalyzes the hydrolysis of phosphoglycerides creating phospholipids, which have detergent properties with a highly polar hydrophilic head and a hydrophobic tail and therefore they are capable of damaging cell membranes by breaking the continuity of its bilayer lipid . They have an important action in the phenomena of hemolysis, myonecrosis, neurotoxicity and anticoagulantion. The myotoxin-type crotalin protein acts through activation of sarcolemmal channels, inhibiting the activity of sarcoplasmic reticulum ATPase with significant depolarization and changes in the osmolarity of muscle fibers with vacuolization and lysis of myocytes and, local necrosis of skeletal muscle. The coagulants and anticoagulants such as the crotaline venoms cause a syndrome similar to disseminated intravascular coagulation (DIC) through an enzyme protein similar to thrombin, which prompts the formation of fibrin monomers, generating an abnormal mesh of fibrin, upon which the factor XIII can not act being lysed by the mechanisms of fibrinolysis as degradation products of fibrin D-dimer. It also contains inhibitors of factor X activation of prothrombin and thrombin and fibrinogenases.
