Bitten by a viper: what you should do… and above all what you should never do

First thing: a viper does not generally seek to attack you

This is important. Snakes tend to avoid humans. A bite usually occurs when the animal feels threatened: when someone steps on it, reaches a hand toward a place where it is resting, lifts a stone, handles wood, or tries to catch it. The bite is above all a defense mechanism.

A bite does not necessarily mean venom has been injected

Here is something many people do not know: a venomous snake can bite without injecting venom. This is called a dry bite. According to the Assurance Maladie, this occurs approximately one time in two for venomous snake bites reported in this context. But you obviously cannot determine this immediately on your own. That is why any suspected snake bite must be taken seriously and assessed medically.

What does the venom do?

Viper venom is not a single substance. It is a complex mixture containing, among other things, various biologically active proteins and enzymes. These can act on tissues, small blood vessels, coagulation and circulation, and trigger a significant inflammatory response. The first manifestation is therefore often local.

What might you feel?

Around the bite, pain, swelling, redness and oedema may appear. And this oedema can gradually spread. For example, the bite is on the hand, then the hand swells, then the wrist, and possibly part of the forearm. It is precisely the progression of this oedema that constitutes one of the key elements of medical monitoring.

But a true envenomation can cause systemic symptoms

When enough venom has been injected, symptoms do not necessarily remain confined to the skin. Nausea, vomiting, abdominal pain, malaise, dizziness, weakness, cardiovascular changes and, in severe cases, respiratory or circulatory manifestations may occur. Severity depends in particular on the amount of venom injected, the location of the bite, the person's underlying condition, their age and their individual response.

And there is another emergency: allergy

As with other venoms, a severe allergic reaction can exceptionally occur. This is anaphylaxis: breathing difficulties, swelling of the face or throat, significant malaise, a drop in blood pressure, loss of consciousness. This is a life-threatening emergency.

So, what should you do immediately?

The first thing is extremely simple: call 15 or 112. Do not wait to see whether it passes. A seemingly minor bite can worsen over time. The symptoms of envenomation can intensify gradually, and assessing their progression is part of the management.

Next: stay calm

I know. It is much easier said than done when you have just been bitten by a snake. But there is a physiological reason for it: the goal is to avoid unnecessary exertion. Do not run to your car, do not continue your hike, do not walk several kilometres if help can come to you. Rest and follow the instructions of the emergency services.

Immediately remove anything that might constrict

This is an extremely important step. If the bite is on the hand, remove rings, bracelets and watches. If it is on the foot or ankle, remove anything that could become compressive if the swelling increases. Why? Because the limb can swell considerably. A ring that feels perfectly comfortable at the time of the bite can become, a few hours later, a genuine compressive band.

Immobilise the limb

Avoid putting unnecessary strain on the bitten limb. The French Health Insurance recommends placing the victim at rest and immobilising the affected limb while waiting for emergency services.

Can the bite be cleaned?

Yes. If conditions allow, clean it with clean water and soap, then with an antiseptic, ideally a colourless one. You can then protect the wound with a clean, dry cloth or dressing. But whatever you do, do not turn the wound into an experimental ground.

A small but very useful step: monitoring the swelling

If swelling begins to appear, it can be helpful to draw its boundary on the skin with a pen and note the time — for example, 6:20 PM. Then, if the swelling extends beyond that line, its progression becomes easy to assess objectively. This is information that can be valuable to the medical team.

Now, let us talk above all about what you should NEVER do

Because this is probably the most important part.

Do not apply a tourniquet

This is an old idea that proves remarkably persistent. The thinking goes: 'I will trap the venom in the leg.' But what you are most likely to do is compromise circulation and worsen local tissue damage. No tourniquet. And no improvised compressive bandage.

Do not cut the skin

You may have seen this in films: a knife incision at the site of the fangs to draw out the venom. Absolutely not. You are adding a wound on top of the bite and significantly increasing the risks of bleeding, infection and tissue damage. And you will not effectively remove the venom that way.

Do not suck out the venom

Neither by mouth nor with an improvised suction device. The venom injected into the tissues does not stay neatly in two small holes waiting to be sucked out. So-called 'venom extractor' devices are absolutely no substitute for proper medical care.

Do not apply ice

It may seem logical: 'It's swollen, so I'll apply something cold.' But for a snake bite, French guidelines advise against applying ice directly to the affected area. No ice on the bite.

Do not drink alcohol

Not even a small glass 'to steady your nerves.' Also avoid coffee or tea while waiting for emergency services, according to French guidelines. The goal is to keep the victim calm and at rest.

And be careful with pain medications

If you are in pain, paracetamol is the analgesic recommended in French first-aid guidelines. On the other hand, do not self-medicate with aspirin or non-steroidal anti-inflammatory drugs, as they can increase the risk of bleeding in this context, among other concerns.

Should you catch the snake?

Absolutely not. That is probably the best way to turn one bite into two. Move away. If you can observe the animal without getting closer to it, simply try to memorise its colour, size and appearance. A photograph may occasionally be useful if it can be taken from a distance and without any risk whatsoever. But never attempt to catch it, kill it, put it in a bag or transport it to the hospital. Your safety takes priority over perfectly identifying the snake.

What will happen in the emergency department?

The medical team will first determine whether true envenomation has actually occurred and assess its severity. They will monitor, in particular, how the swelling progresses, the pain, blood pressure, heart rate, breathing and the appearance of any systemic symptoms. Laboratory tests may be necessary, particularly to check for effects on clotting and other bodily functions. And above all, not every viper bite automatically requires antivenom.

So, when is antivenom used?

Antivenom is a genuine medical treatment. It contains antibodies capable of neutralising certain components of the venom. But it is not administered simply because two fang marks are visible: the decision depends on whether envenomation is present and how severe it is. In significant cases, antivenom may be the specific treatment required. This is precisely one of the reasons why hospital assessment is so important.

Are viper bites fatal?

They can be serious, but we must avoid creating disproportionate fear. In metropolitan France, snakebites remain relatively rare, and most envenomations do not lead to a dramatic situation when they are managed correctly. But a viper bite remains a potential emergency. The right response is therefore neither to panic nor to dismiss it: it is to call for help and apply the correct measures.

How can you avoid being bitten?

When you are walking in an area where vipers may be present, watch where you put your feet, stay on marked paths as much as possible, wear appropriate footwear, and be careful in tall grass. Do not put your hands under a rock without looking first, and be cautious around old stone walls, woodpiles, scrubland, and sun-exposed rocky areas. A walking stick can also be useful: the vibrations produced by walking tend to drive snakes away.

And teach this to children

A snake is not an animal you touch to see what it will do. Even if it appears motionless, even if it looks small, even if you think it is a grass snake. And above all, a motionless snake is not necessarily dead. You do not touch it.

If you only had to remember 7 things

After a suspected viper bite: call 15 or 112 immediately; rest and avoid walking or running unnecessarily; remove rings, bracelets, watches, and any object that could compress the limb; immobilize the limb and follow the instructions of the emergency services; never apply a tourniquet; do not cut, suck, or apply ice to the bite; and never try to catch the snake.

I am Dr Florian Vallecillo. And if I were to leave you with just one idea today, it would be this: after a viper bite, what matters is not playing the hero — it is not wasting time, and above all not making the situation worse with the wrong actions. No tourniquet, no incision, no suction, no ice, no running to reach your car. Stay calm, rest, immobilize the limb, and call 15 or 112. Because in emergency medicine, knowing what not to do can sometimes be just as important as knowing what to do.