Snake, centipede and scorpion bites in Vietnam: what helps and what harms

Almost nobody comes to Vietnam and meets a snake. The people who do are usually walking a paddy bund at dusk, reaching into a woodpile, clearing a garden in the hills, or wading a flooded lane after a storm pushed water through somewhere that was dry an hour earlier. Centipedes turn up far more often than snakes. Usually inside a shoe, or under a damp towel on a ground floor.

The useful thing to know in advance is not which species live here. It is that the standard first aid most people half-remember from films is the part that does the damage. The treatment that works lives in hospitals. Not in anything you can carry. This page is background, not a diagnosis of a bite you are looking at.

Bites that mean hospital immediately

Envenoming can be slow to show and then move quickly. If any of the following appears after a bite or sting, ring 115 or get to the nearest hospital emergency department straight away — a bitten person belongs in a vehicle, not waiting at an address for a clinician to travel out to them:

• Drooping eyelids, double vision, a thickened voice, or difficulty swallowing saliva
• Weakness that spreads, or a feeling that the chest is becoming harder work
• Swelling that climbs past the ankle or the wrist within an hour or two
• Bleeding that will not stop from the puncture marks, the gums, or old scratches
• Blood in urine, vomit, or stools, or bruising spreading away from the bite
• Any collapse, fainting, or a racing pulse with cold hands
• Lips, tongue or throat swelling, or a rash spreading with breathlessness — that is an allergic reaction and it does not wait
• A bite in a small child, in pregnancy, or anywhere on the head or trunk

Antivenom is given under observation. It carries its own reaction risk. The dosing is decided on repeated examinations and blood clotting tests over hours. That makes it hospital work from the start. The hours saved by going directly are the hours that matter.

What actually bites people here

Two groups of snake account for nearly all serious envenoming in Vietnam. They behave differently enough that a hospital treats them as separate problems.

Start with the vipers. The Malayan pit viper in the lowlands and the green pit vipers in bamboo and garden shrubs cause immediate, severe local pain, swelling that marches up the limb, blistering, and disordered blood clotting. The elapids are different. Monocled cobra, king cobra, and the kraits do far less to the skin and far more to the nervous system. A krait bite can be nearly painless. That is the reason people go to bed after one.

• Green pit vipers sit in hedges and fruit trees at head and hand height, which is why gardeners get bitten on the fingers
• Kraits are nocturnal and often come indoors in the rainy season, including into rooms at ground level
• Scolopendra centipedes, the dark ones a hand long, deliver a sting that is genuinely vicious but almost never dangerous
• Scorpions in Vietnam are painful rather than life-threatening in adults, with the usual exceptions of children and allergic reaction

The first hour, done properly

The aim is simple. Slow the spread of venom through the lymphatics, keep the person calm, and get them somewhere that holds antivenom. Everything on this list is unglamorous and all of it helps.

• Sit or lie the person down and stop them walking on a bitten leg. Movement pumps venom along
• Immobilise the limb with a splint the way a fracture would be splinted, and keep it roughly level with the heart
• Take off rings, watches, bracelets and anklets before swelling makes that impossible
• Draw a line on the skin where the swelling has reached. Write the time beside it, then repeat it as things change. That record tells the hospital the speed of progression, which no one can reconstruct later
• Clean the puncture gently with water. Do not scrub it
• Photograph the snake from a safe distance if it is still visible. Never try to catch or kill it — second bites happen during exactly that
• Take the person to hospital by car or taxi, not on a motorbike. Ring ahead if you can, so the department knows a bite is coming

Five pieces of first aid that make it worse

This is the part worth reading twice. Every item on it is still widely taught. Each one has its own way of causing harm.

• A tourniquet. Tight bands cut off arterial blood. They concentrate venom in the tissue beyond them, and cost people limbs. When one is released after a long period the sudden surge is its own crisis
• Cutting the wound, or suction — by mouth or with a kit. It removes a negligible amount of venom and adds a contaminated wound to the problem
• Ice. Cold reduces blood supply in tissue that is already struggling and worsens the damage underneath
• Electric shock, petrol, kerosene, or burning the site. These appear in folk advice across the region and do nothing except injure skin
• Herbal poultices and tying a stone over the bite. The harm is mostly the delay they buy. Delay is the variable that decides outcomes

Dry bites, and why you stay observed anyway

A large share of bites from venomous snakes inject little or no venom. That is good news with a trap inside it. A person who feels fine two hours in can still be at the start of a krait bite, where paralysis builds overnight. Hospitals therefore observe bites rather than discharging them on how well the patient looks.

The observation is not a formality. It is serial examination of eyelids, grip, swallowing and breathing, plus clotting tests repeated over time. Those repeats are what catch the slow cases. A bite is not something to sleep off and reassess in the morning.

Centipede and scorpion stings

A Scolopendra sting hurts out of all proportion to the mark it leaves. Redness, local swelling and pain that radiates up the limb are typical. The pain can last much of a day. Wash the site. Use whatever simple painkiller you already take, at the dose printed on its packet, and keep the limb up. Warm water soaks are more comfortable than cold for most people.

What deserves attention is the small number of stings that become infected a day or two later, and the rarer allergic reaction. Spreading redness with heat and a fever belongs in front of a clinician, not under another dressing.

Scorpion stings here follow a similar course. In a child, or where the pain comes with sweating, vomiting, agitation or a fast heart rate, treat it as urgent and head for hospital rather than waiting it out.

Tetanus and the wound itself

Every puncture from an animal raises the tetanus question. Most travellers cannot remember when they last had a booster. If the answer is more than ten years ago, or unknown, settle it at the same visit. It is a short conversation. It closes a risk that has nothing to do with venom.

Secondary bacterial infection is the other late problem. A bite that was improving and then becomes more painful on day two or three, with spreading redness, is behaving like an infected wound. It needs reassessing.

Where bites actually happen

The geography is predictable. Rice paddies and their bunds at dusk and after dark. Karst and forest paths around Phong Nha and Kon Tum, where leaf litter hides what is in it. Gardens and plant nurseries in the Da Lat highlands. Construction sites. Ground-floor rooms and outdoor bathrooms during heavy rain, when water moves animals out of flooded ground and towards buildings.

What a clinician at your accommodation can and cannot do

Being honest about the boundary matters here more than in most of our guides. We hold no antivenom, and nobody outside a hospital pharmacy should. A visit to where you are staying is the right call for the aftermath. A centipede or scorpion sting that is painful but settled, a healing puncture that needs cleaning and dressing, a tetanus booster, or a wound that has turned on day three.

For a suspected venomous snakebite, our answer is a vehicle and an emergency department, said plainly on the phone. We can tell you which hospital to aim for, ring ahead, and follow up afterwards with dressings and a written report for an insurer. What we will not do is send someone to sit with a bite that needs antivenom.

Worth carrying away

Immobilise, mark the swelling with the time, remove jewellery, and travel to hospital. No tourniquet, no cutting, no ice, no suction. A painless bite is not a safe bite, especially at night. And the signs in the second section above mean an emergency department now, not an examination where you are staying.