What are the other Names for this Condition? (Also known as/Synonyms)

• African Puff Adder Snake Bite
• Bitis Arietans Snake Bite
• Common Puff Adder Snake Bite

What is Puff Adder Snake Bite? (Definition/Background Information)

• The puff adder (Bitis arietans) is a common and venomous snake, about 3-5 feet long with a heavy body (average size is 1m) and found across large parts of the African continent and some parts of western Arabia. The snake belongs to the viper family or Viperidae
• It is an ambush predator that inhabits the African savannah (mixed wood and grass regions) and vast open grassland areas. The snake generally lies motionless and appears docile, but will let out a puffing and hissing sound as a warning sign when disturbed. Puff adders prey on small mammals, rodents, rabbits, lizards, and sometimes, even on insects (grasshoppers and cockroaches)
• The puff adder is a nocturnal reptile that blends excellently with its surrounding and is difficult to spot by both prey and predator. Since, it is found widespread across Africa, the coloring pattern of the snake too varies from one geographical area to another
• However, the markings on its body are distinct, consisting of bands and mosaic-like patterns that are regular and repetitive along the length of the snake. The colors may vary from shades of brown, black, orange, yellow, grey, and white
• Two subspecies of puff adders are described in the scientific literature, based on the region they are found in:
  • Common puff adder (Bitis arietans arietans) that is widespread across most of Africa
  • Somali puff adder (Bitis arietans somalica) that is found only in the country of Somalia and in parts of north Kenya
• Human interactions occur frequently when people accidentally tread on the snake as they walk through forests and grasslands. The attacking or biting strike of the puff adder is extremely fast (one of the fastest in the snake kingdom) and it can release enough venom to kill a fully grown adult male
• Puff Adder Snake Bite can result in fatalities due to systemic envenomation (venom injection through a bite) within 24-26 hours, if the condition is left untreated. The common puff adder is responsible for the maximum number of snake bite related deaths in Africa
• The signs and symptoms of Puff Adder Bite may include initial symptoms confined to the affected limb, such as pain, swelling, blistering, along with nausea and vomiting. Severe widespread symptoms and complications may involve the cardiovascular, hematological (blood-related) and kidney and urinary systems
• Early administration of suitable antivenom (or antivenin) is the mainstay of treatment. Apart from this, symptomatic treatment is necessary, which may include the use of vasopressor agents, blood transfusion, and peritoneal dialysis. The prognosis of Puff Adder Snake Bite with prompt and effective therapy is usually good

Who gets Puff Adder Snake Bite? (Age and Sex Distribution)

• Puff Adder Snake Bite may occur to any individual exposed to the snake, particularly in its natural habitat
• More number of cases are reported in children and young adult males, although individuals of any age and gender are prone to snake bite
• The distribution of puff adder includes the whole of African continent, with the exception of Sahara desert and the tropical rainforests (parts of Central Africa and coastal West Africa). The snake is also found in countries to the north of Africa such as Morocco and Algeria
• In the Arabian peninsula, the snake is found in the southwestern region of Saudi Arabia, the whole of Yemen, and some areas of Oman

What are the Risk Factors for Puff Adder Snake Bite? (Predisposing Factors)

The risk factors for Puff Adder Snake Bite include the following factors:

• Living or residing in areas where the puff adder is found; there is a higher risk for people in the country side and rural regions of the endemic zones (Africa and parts of Arabia)
• Occupational hazard: The snake may pose a threat to those working in fields, plantations, and herding cattle
• Walking barefoot or unprotected through open grasslands and savannahs; the puff adder is generally known to lie motionless near footpaths and clearings, basking in the sun
• Venturing outdoors during the night such as for toilet
• During nights, the snake may enter easily accessible households in search of prey (such as mice and rats) and inadvertently strike humans
• In snake-infested areas, having thatched or hay mounted roofs (or even cracked mud walls) may offer them space to cool and hide
• Having dwellings close to water sources (such as ponds) that attract frogs
• Walking or sleeping in farms and fields, particularly at night (usually noticed among migrant workers) and during harvest seasons
• Wildlife enthusiasts and scientific study groups, who explore the region
• Keeping them as pets
• Handling dead or live puff adders; intentionally or accidentally picking up the snake
• The snakes are excellent swimmers and are also known to climb low-lying bushes, thus putting individuals at risk near water bodies and bushy thickets too

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Puff Adder Snake Bite? (Etiology)

Puff Adder Snake Bite takes place when one comes into contact with the venomous puff adder, usually unintentionally or inadvertently.

• Individuals who fail to read or do not sense the warning signs of puffing and serpentine-like coiling motion of the snake have a greater risk of being bitten by the snake. The puff adder can strike lightning-quick, either forwards or sideways
• Puff Adder Bites can cause injection of a cytotoxic venom into the body or limb. Cytotoxins interfere with cell function and cause rapid cell destruction. This leads to local and systemic signs and symptoms depending on the amount of venom that is injected

According to scientific literature, the rate of envenomation of puff adder is between 60-80%.

What are the Signs and Symptoms of Puff Adder Snake Bite?

The signs and symptoms of Puff Adder Snake Bite can vary from one individual to another. The signs and symptoms depend on the age (whether child or adult), weight, and overall health status of the individual (whether having an underlying condition or illness). Also, the signs and symptoms vary according to the potency and amount of venom injected.

The common signs and symptoms of Puff Adder Bite that may develop within a period of 3-4 hours may include:

• Severe pain at the bite site; presence of noticeable fang marks
• In a majority of cases, snake bites occur on the feet and ankles followed by the hands
• Skin discoloration and swelling that slowly involves a wider region
• Bleeding from the wound; the oozing blood is thin
• Blistering of skin (like formation of bubbles)
• Swollen lymph nodes
• Headaches
• Sweating
• Nausea and vomiting
• Abdominal pain and diarrhea
• Death of tissue (or necrosis) around the affected region or limb, observed within a few days
• Low blood pressure that is onset immediately
• Fainting, dizziness
• Weakness and malaise
• Partial consciousness or unconsciousness

Some of the systemic signs and symptoms may include:

• Heart-related abnormalities such as slow or fast ‘resting heart rate’
• Decreased blood platelets
• Internal hemorrhage and gastrointestinal bleeding including:
  • Blood in urine
  • Bleeding from the nose
  • Bleeding from recent wounds
  • Mucosal bleeding (seen a few hours after the bite) from the gums, eye, gastrointestinal tract, etc.
  • Anemia due to spontaneous bleeding
• Acute kidney injury or kidney failure
• Neurological symptoms are generally not observed

Note: 

• In some cases, the fang marks may not be pronounced or even visible on the skin. Sometimes only small scratch marks or lacerations may be observed. Thus, any contact with a puff adder merits immediate medical attention
• Severe anxiety may also result in some misleading symptoms of snakebites, such as sweating, fatigue, and shock, even when no bite has taken place (the individual may be imagining), or when it is a dry bite. Nevertheless, even in suspect cases, the presence of any such symptoms requires the attention of a qualified medical professional
• Also, if the individual has been treated using alternative/native medicines, it may present additional confusing symptoms. Thus, it is important to always consult a qualified healthcare provider promptly

How is Puff Adder Snake Bite Diagnosed?

Puff Adder Snake Bite may be diagnosed using the following tests and exams:

• Complete physical examination with comprehensive evaluation of medical history; a physical examination of the affected site by the physician may be normally sufficient to diagnose a snake bite
• The individual may be asked to provide an account (history) of the events that occurred (what took place and how), if possible
• Assessment of the signs and symptoms exhibited by the individual may be carefully observed
• Blood tests that may include: (many of these tests are repeated over the course of treatment)
  • Complete blood count (CBC) with differential and platelet count
  • White blood cell count
  • Hematocrit blood test: Hematocrit is the proportion of blood that is made up of red blood cells
  • Prothrombin time (PT) and partial thromboplastin time (PTT) tests
  • Fibrinogen blood test
  • Lactate dehydrogenase (LDH) test
  • Serum electrolytes including blood urea nitrogen (BUN) and creatinine levels
  • Arterial blood gas
• Urine test or urinalysis to test for free protein, myoglobin, and hemoglobin levels
• Continuous urine output monitoring is helpful to determine damage to the kidneys, if any
• Electrocardiogram (ECG)
• Kidney function test
• Liver function test

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Puff Adder Snake Bite?

The complications of Puff Adder Snake Bite may include:

• Multiple bites, causing injection of a large quantity of venom; the puff adder can reportedly bite more than once with a single strike
• Blood clotting defects resulting in severe internal bleeding
• Disseminated intravascular coagulation (DIC) resulting in blood clot formation in the body
• Severe deep tissue and muscle damage of the affected leg or hand, which can result in superimposed infections and gangrene formation
• Increased pressure causing compartment syndrome, which is an urgent medical condition
• Local envenomation causing debilitating limb injury and irreversible muscle damage
• Loss of limb function, necessitating amputation
• The snake toxin can damage the muscle resulting in muscle breakdown known as rhabdomyolysis. Extensive muscle breakdown can lead to a variety of complications including kidney failure
• Severe shock
• Seizures and coma
• Kidney failure

Presence of misleading symptoms due to fear and anxiety, which may be also aggravated by those around the individual, such as one’s family members, can sometimes result in inappropriate or over-treatment.

Antivenom reactions:

• Some individuals may develop an allergic reaction, such as anaphylaxis, to the antivenom that may be serious. This may develop within 10 minutes or even after 6 hours, typically starting with itchiness over the scalp and other skin areas
• Life-threatening anaphylactic reactions that require immediate medical treatment may include:
  • Low blood pressure or hypotension
  • Bronchospasm causing narrowing of the airways (bronchi) resulting in breathing difficulties
  • Angioedema: Swelling of skin tissue layers at various locations including the throat, causing speaking and breathing difficulties
• Serum sickness may develop as a complication of antivenom therapy causing fever, nausea, itchy skin, muscle and joint pain, etc. It may develop after 4 days or even 2 weeks (average 7 days) following the administration of antivenom serum

Cardiovascular, hematological, and kidney abnormalities can result in severe complications including death.

How is Puff Adder Snake Bite Treated?

All snake bites should be considered as medical emergencies and evaluated by trained medical professionals, as soon as possible; the first 6-8 hours are particularly vital for preventing life-threatening symptoms. Failure to obtain early assessment and management from the highest level of care (available within the community) may potentially result in severe complications and death.

The following measures may be considered in the treatment of Puff Adder Snake Bite, based on the medical evaluation of a trained healthcare professional:

• Administration of Ringer's lactate solution (to keep the patient well-hydrated)
• Administration of anti-snake venom (ASV) to neutralize the venom through slow intravenous injection or infusion method; the ASV type administered is polyvalent antivenom
• Address any signs or early allergic reaction: A close observation of the patient is necessary for a minimum of 60 minutes immediately following antivenom administration, to detect early allergic reactions, if any
• Periodic blood and urine tests are undertaken for 12-24 hours or more
• Tetanus vaccination is usually required, if it is not up to date
• The patient is generally admitted and placed in an ICU setting and monitored for at least a day following the abatement of symptoms; the patient has to be rested and kept warm
• Strict bed rest to prevent trauma may be advocated in case of hemostatic abnormalities that arises from a hemotoxic/cytotoxic venom (the venom can result in increased bleeding tendencies leading to substantial blood loss even to minor trauma)
• If necessary, blood and plasma transfusions for severe cases
• Medications to increase blood pressure such as vasopressor drugs and plasma expanders
• Administration of anticholinergic medication for those with low blood pressure causing abnormally slow heart rate (bradycardia). Such anticholinergic medications help increase the heart rate and blood pressure
• Peritoneal dialysis for acute kidney failure
• Providing life support, such as ventilation assistance and treatment for shock, for those with severe symptoms leading to potential organ failure
• Pressure management (using wick catheter or appropriate pressure devices) of affected limb for compartment syndrome; in rare cases, it may merit a fasciotomy
• Removal or necrotic tissue through surgical debridement
• Rehabilitation of the affected limb through physical therapy
• Unless infection or tissue necrosis is observed, the administration of prophylactic antibiotics is generally not recommended in snake bites. However, the healthcare provider will determine whether antibiotics administration is necessary or not, based on one’s individual circumstances

Note:

• Consultation with a medical toxicologist is recommended for all cases requiring the administration of anti-snake venom
• Even though antivenom therapy is the key treatment for systemic envenomation; on its own, it may never be adequate enough to completely resolve the condition. Other supportive and symptomatic measures are always necessary to save the patient
• The dose of antivenom does not vary for a child, adult, or even for a pregnant woman, since the snake typically injects the same quantity of venom into an individual
• Gynecological evaluation may be necessary for pregnant women bitten by snakes to evaluate the health of the fetus
• In many instances, the type of venomous snake involved in the bite is unknown; hence, all vital organs and systems should be closely monitored and treated appropriately, as necessary

How can Puff Adder Snake Bite be Prevented?

Puff Adder Snake Bite may be avoided by:

• Learning to recognize puff adders using the following tips:
  • The snake moves like a caterpillar, in a linear manner; the tracks of a puff adder on sand are usually along straight lines
  • It stays perfectly still, until approached very closely or disturbed
  • Puff adders provide warning signs of puffing and hissing when approached
  • Before striking, they continuously coil in a spiral or serpentine manner
• If you spot a puff adder, step back slowly and keep a safe distance of at least 8-10 feet or more (between yourself and the snake)

Outdoors:

• Being alert, if you are outdoors in snake-infested regions, particularly containing dangerous species of snakes
• Avoiding being outdoors at night in forested areas (puff adders are generally nocturnal); be careful while camping outdoors
• Avoid tall grassy areas or thick bushes; if you plan to explore the area, use heavy boots and thick pants
• Always step on top of large rocks and fallen trunks; never place one’s foot by the side of big rocks and rotting tree stumps. Some snake species are known to take shelter or warm themselves on the sides, during the day
• Always check before sitting on dead tree logs, stumps, or a pile of rocks; use a stick to stir or probe around the area
• While walking through areas with thick undergrowth, pay attention to the sound of birds or monkeys that may warn of potential dangers such as snakes
• While walking outdoors at night, use a flashlight or lamp and make constant noise (singing or talking to others) or large stomping sounds that may alert the snake to move away from the region
• While walking through tall grass or undergrowth, try to walk one behind the other in a single file
• Never probe holes on the ground or termite mounds with bare hands or even using small sticks; avoid clearing low-lying bushes using one’s hands
• Avoid snake-infested regions or even walking on cleared forest paths and roads during nights, immediately after heavy rains that may flush snakes out to the open, due to flooding of their burrows and holes
• Carry a snake bite kit, if possible, when traveling through areas containing highly venomous snake species

Residential settlements:

• Keep homes and surrounding areas clean and clear of rubbish or leafy piles, termite mounds, even building materials (like bricks and large stones)
• Cut tall and unkempt grass or low-lying shrubs and bushes around dwelling areas that provides hiding places for snakes and other rodents
• Avoid keeping farm animals and birds (particularly chickens and ducks) and food grain storage yards in, near, or adjacent to the house
• In regions where snakes are regular home visitors, always switch on the lights before entering one’s shed or garages (and try to stand clear of exits that may serve as possible escape routes for the snakes)
• Natural disasters, such as floods and forest fires, are known to drive out snakes and other creatures into homes seeking shelter. Hence, always remain vigilant when returning home following such situations
• Never intentionally run over snakes on the road while on a vehicle (cycle, other 2-wheeler, or 4-wheeler); the injured snake lying on the road may strike other pedestrians, or get entangled in the vehicle and be carried to the parking lot or even inside one’s garage

Occupation-related:

• Avoid collection of firewood at night, especially in lowlight or under moonlight
• Exercise vigilance while working in farms, particularly during the harvest season or after flooding
• Ensure that employers provide adequate protective clothing (gloves, boots, etc.) to those who work in high-risk (for snake bite) occupations such as agriculture or fishing industry

Other points to consider:

• Avoid playing with or teasing snakes such as by touching their tails
• Do not pick up dead snakes - they may be poisonous and still bite through a reflex action
• Do not reach into dark nooks/corners/recesses with your bare hands/foot
• Teach and educate children about the dangers and importance of snakes
• Take steps to educate the members of a community to identify venomous snakes, recognize bite symptoms, and how to avoid encounter with snakes
• Completely avoid any form of native or traditional treatment for snake bites

Both large and small snakes have the potential for severe envenomation; hence, all snake bites should be treated promptly and appropriately.

What is the Prognosis of Puff Adder Snake Bite? (Outcomes/Resolutions)

• The prognosis of Puff Adder Snake Bite is dependent on the site of bite, overall health of the individual, promptness of medical response, and continued observance and treatment of complications following admission of the patient. In many cases, the prognosis is good with immediate treatment and administration of antivenom
• Without treatment or access to proper healthcare, deaths are reported in nearly 15% of the cases, usually within 12-24 hours. Inadequate administration of antivenom (in insufficient quantities) is also known to result in fatalities
• However, when severe symptoms and complications of poisoning are observed, the death rate is over 50%. Individuals typically die from blood and heart-related abnormalities

Additional and Relevant Useful Information for Puff Adder Snake Bite:

• The puff adder takes the first place in snake bite related deaths in the whole of Africa, which can be attributed to wide distribution of the snake and poor access to healthcare facilities and antivenom serum across the region
• A single bite of the puff adder can inject enough venom to potentially kill 3-5 adults
• In some cases, the snake bite may be a ‘dry bite’, meaning that even though there is a bite mark, no venom injection occurs. However, even for dry bites, the patient must be placed under observation and monitored closely for a period ranging anywhere from 12-24 hours, prior to discharge

Depending on the geographical region, either monovalent antivenom or polyvalent antivenom may be administered for systemic envenomation. Monovalent antivenom neutralizes venom of a single snake species only, whereas polyvalent antivenom can neutralize the venom of several snake species.

The snake venom is a highly complex mix of several proteins, enzymes, amino acids, peptide chains, fats, and even certain metals. The bite causing venom injection into the body may be categorized as:

• Intramuscular injection: Long-fanged snakes have a potential for injecting venom directly into the muscles (this is highly infrequent though)
• Intraperitoneal injection: When the snake bite involves the stomach or abdomen region
• Intravenous injection: In very rare cases, the snake fangs may inject venom directly into a blood vessel, releasing venom directly into blood (posing an even greater danger than normal snake bites)
• Subcutaneous injection: A majority of snake bites involve the subcutaneous skin layers (venom is injected just below the skin surface)