Wasps, bees, horseflies and jellyfish: what to do if you get stung or bitten?

With the arrival of summer, you may be stung by a wasp or bee, bitten by a horsefly or viper, come across the tentacles of a jellyfish or step on a weevil. What can be done for correct and immediate help?

Wasp, hornet, bee and bumblebee stings


– Insect sting, what to know?

The reaction to the sting of hymenoptera, i.e. wasps, hornets, bees and bumblebees, is very subjective as it depends on the individual’s immune response.

When stung, these insects inject a certain amount of venom* which our body recognises as foreign and tries to fight it off, so to speak.

Depending on individual sensitivity, symptoms can vary, ranging from normal local manifestations (skin reaction) to involvement of the whole body (systemic reaction).

This explains why in some people a wasp sting causes only a little pain and mild discomfort at the site of the sting, which passes within a few hours, while in others, the same sting can cause more severe reactions that in some cases can even lead to death.


Hymenoptera use their sting to defend themselves.

When they sting us, they cause pain both by mechanical action and (mainly) by the presence in the venom of substances that irritate and stimulate the pain nerve fibres.

The amount of venom injected by a wasp is not always the same, depending on whether it has already stung someone else or some insect/animal before stinging us: if this is the case, its venom vesicle contains very little venom.

The hornet, on the other hand, injects up to three times as much venom as the common wasp, which is why it causes more pain and can cause a more serious reaction.

Bees rarely sting and if they do, it is because they feel threatened.

After the sting, the serrated stinger remains ‘stuck’ in the skin and continues to contract, injecting venom.

The bee tries to fly away and dies as its abdomen tears.

This is a ‘sacrifice’ to defend the hive: when it dies, in fact, a pheromone known as the ‘alarm pheromone’ is released to warn other bees of imminent danger.

For this reason, when you are stung by a bee it is important to move away quickly from the place where you are and to take care not to be attacked by the swarm if you are in the vicinity of a hive.

– Hymenoptera sting, what to do?

1) Remain calm: first of all, it is important not to panic, and in the event of a child being stung, parents must not create agitation in the child.

2) Watch out for the sting: look at the site of the sting to make sure there is no sting.

Wasps, bumblebees and bumblebees have a smooth sting and rarely remain in the skin, while the sting of the bee is serrated and when it stings it remains ‘stuck’ in the skin together with the venom vesicle (a white sac containing the venom) which continues to contract and inject venom: it is important to quickly remove the stinger with the edge of the nail without crushing the vesicle with the fingers to avoid releasing more venom.

3) Observe the symptoms: there may be different local or systemic reactions depending on the extent and symptoms for which a targeted therapeutic intervention is envisaged. Let’s look at the individual situations in detail.

Local reaction

-> Limited

In most cases a hymenoptera sting causes a reaction around the sting characterised by pain, swelling and redness, which usually subsides within a few hours.

What to do? In these cases, it may be helpful to put ice on the bite to reduce the swelling and a cortisone ointment to treat the inflammation (redness, pain, swelling).

If you have any doubts, ask your doctor or pharmacist.

-> Extended

It can happen that within a few tens of minutes or hours the skin reaction extends beyond 10 cm from the puncture site: for example, if you are stung on a hand, the swelling and redness reaches up to the elbow, but no other symptoms appear (e.g. dizziness, breathing problems, diffuse urticaria – see Systemic Reaction).

The extensive local reaction usually resolves within a few days to a week.

What to do? As with limited local reactions, it is useful to put ice on it immediately to reduce swelling and to take cortisone and antihistamine by mouth to treat the associated inflammation and itching, and then to consult your doctor or pharmacist.

Systemic reaction

-> Diffuse urticaria

If, within 15-30 minutes of the sting, redness appears all over the body and is accompanied by mosquito bite-like bumps (diffuse urticaria), the reaction is systemic, i.e. it involves the whole body, even if it only affects the skin/mucosal system.

What to do? In the absence of other symptoms (see Anaphylactic reaction) this is a reaction of low severity, but it is necessary to go to the Emergency Department for a check-up and for the prescription of an adequate cortisone and antihistamine therapy.

-> Anaphylactic reaction

An anaphylactic reaction occurs when, in addition to the skin, other systems such as the cardiovascular, respiratory and gastrointestinal systems are involved.

At least two of the four target systems of anaphylaxis must be involved, but all four can also be involved simultaneously.

Some symptoms are as follows:

– dizziness, lowering of blood pressure, feeling faint (involvement of the cardiovascular system);

– intense acute rhinitis (sneezing, cold, watery and swollen eyes), asthma, difficulty in breathing, feeling of swelling in the throat (respiratory system involvement);

– intense abdominal cramps, nausea, vomiting (gastrointestinal system involvement).

What to do?

An anaphylactic reaction usually occurs 5 to 20 minutes after the sting. You should go quickly to the nearest emergency room.

-> Anaphylactic shock

The most serious situation of an anaphylactic reaction is anaphylactic shock where all four systems are involved with marked hypotension (drop in blood pressure) leading to loss of consciousness.

What to do?

You should go immediately to the nearest emergency room, as adrenaline has to be administered in such cases.

To deal with emergencies, there is adrenaline by self-injection, a life-saving drug that you should always carry with you, especially if you have already had an allergic reaction to hymenoptera stings.

This treatment is the first approach to an anaphylactic reaction to hymenoptera venom, in addition to cortisone and antihistamines.

It is advisable to go to the nearest emergency room and, in the event of a severe drop in blood pressure, to lie down in the back seat with your legs raised.

How to prevent a stinging insect bite

  • Avoid wearing bright colours and perfumes or deodorants with fragrances that are too strong to attract insects
  • Wear long-sleeved shirts, trousers, shoes and a hat to minimise skin exposure
  • Use insect repellent sprays on exposed skin
  • Use insect repellent products when outdoors (garden, terrace…)
  • Do not leave drinks, sweets or food in the open air. Avoid leaving open drinks cans that have not been fully consumed.
  • Check for insects before sitting, lying down or otherwise staying outdoors
  • Avoid walking in areas where there are insect colonies (e.g. orchards, beehives, flowering meadows…)
  • Wear gloves if you pick fruit, even if it has fallen to the ground.
  • Do not attempt to crush wasps or bees under any circumstances. It increases the risk of being stung and attracting the swarm.
  • Do not use your arms to ward off the hymenoptera and do not make rapid movements. If you find yourself in an area where there are bees or wasps, walk slowly and back away so as not to annoy the insects.

Horsefly bite

– What to know?

The horsefly is similar to a large fly; it does not sting but bites to suck the blood needed to produce eggs.

As with mosquitoes, these are female horseflies.

Their bite is very painful because of the particular shape of their mouths, which tear the skin.

The mandibles of these insects, in fact, resemble, so to speak, small sharp scythes: initially they are joined, but as they bite they open outwards to let out more blood.

Horseflies and mosquitoes, as well as all hematophagous (blood-sucking) insects, inject substances with anticoagulant action during the bite to keep the blood flowing.

Their saliva contains irritants similar to those of hymenoptera, which are responsible for the local skin reaction characterised by redness and the formation of a pomphoid at the site of the bite. Although this reaction is rare, in more sensitive people the bite of horseflies (and mosquitoes) can cause an allergy.

– What to do?

A horsefly bite leads to a small wound that bleeds.

Wash and disinfect the area carefully.

Ice the area to counteract the swelling and use a cortisone ointment to reduce the inflammatory effects (redness, pain and swelling) triggered by the irritants injected during the bite.

Within a few days the situation returns to normal, but it is important to check that the wound does not become infected.

If the swelling spreads, you can contact your doctor or pharmacist.

Although rare, if you experience other symptoms such as widespread hives, dizziness or difficulty breathing, you should go to the emergency room.

Viper bite

– What to know?

Vipers rarely bite, they only do so if they are annoyed. Generally, carrying a stick to beat them with is enough to make them flee, as they are very sensitive to ground vibrations.

– What to do?

If you are bitten, it is important not to panic, but to go to the nearest emergency room.

If you are bitten on the arm or leg, it is important to move the limb as little as possible to slow the spread of the venom into the bloodstream, and to remove rings or bracelets so that they are not difficult to remove in the event of swelling.

There are many snakes and it is very useful for rescuers to know whether it is a viper or another snake so that they can administer the most appropriate treatment (e.g. anti-viper serum).

If you can, and you are not a snake expert, take a photograph.

Do not incise the wound or attempt to suck out the venom.

Jellyfish and anemones

– What to know?

Jellyfish and anemones are close relatives.

They have stinging cells at the end of their tentacles which release their venom when touched.

The sensation on the skin is a strong burning sensation.

In other words, the reaction is similar to that of putting acid on your skin. Depending on the type of jellyfish or anemone and the amount of tentacles you come into contact with and which remain attached, the affected skin area may be slightly reddened or may have blisters and second degree burns.

– What to do?

Get out of the water immediately.

It is important to remove any pieces of tentacle within a few minutes using a soft cloth moistened with sea water or salt water.

Do not use your fingers as they will also be burnt.

Do not rinse with fresh water because the different osmotic pressure would cause the vesicles containing the venom to explode and make the situation worse.

Use the edge of a credit card or the back of a knife blade to gently ‘swipe’ the area to remove all the vesicles present, which are often not easily visible.

The toxins contained in the poison are thermolabile, i.e. they work well at low temperatures (such as that of the sea), but are inhibited at higher ones.

To counteract the action of the poison and get more relief, once the area has been examined and cleansed, warm (not boiling) salt water can be used to:

sponge the affected area from above by sprinkling water on it without touching it with hands, sponges or cloths to avoid further irritating the injured area;

If possible, immerse the affected area in warm salt water.

If possible, soak the affected area in warm salty water. After treating the area in this way for about ten minutes, allow it to dry.

Consult your doctor or pharmacist to assess the treatment needed according to the type and extent of the injury (cortisone ointment, healing dressings, oral antihistamine).

Rarely do these toxins cause allergies, and usually the lesions are caustic to the skin.

If you experience other symptoms such as diffuse urticaria, extensive swelling, dizziness, loss of consciousness, go to the nearest emergency room.

Do not use ice as this will make the situation worse, as cooling the area will facilitate the action of toxins in the skin.

Urine or ammonia are also not effective methods.

Spider fish

– What to know?

Spiderfish are fish that hide under the sand.

They have a dorsal fin made up of several spines on their back, which is normally closed and is snapped open when they feel in danger.

You may inadvertently step on it when entering the water.

The sting is very painful because of the toxins contained in the venom.

Often the pain is so great that you cannot move your whole leg, you feel dizzy, nauseous and vomit.

– What to do?

First of all check that there is not a piece of sting left.

Then, to counteract the effect of the poison, use warm water to inhibit the toxin.

It may also be useful to squeeze the wound to release some of the injected venom.

Painkillers can be used to treat the pain.

Read Also:

Insect Bites And Animal Bites: Treating And Recognising Signs And Symptoms In The Patient

What To Do In Case Of A Snakebite? Tips Of Prevention And Treatment

Ibiza, Young Tourist Bitten By A Brown Recluse Spider: He Lost Two Fingers


Policlinico di Milano

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