Bee Stings

18th October 2012 lecture given by John P Gower

John is a surgeon who became interested in bees and bee stings after a patient had an extreme allergic reaction to a sting.

People have around 40,000 stings a year. From his experience most are from wasps. Around 20 people have anaphylactic reactions. Anaesthetic drugs kill about 10 people a year, nuts kill about 5 people a year and insect stings from wasps and bees kill about 4 people a year. Roughly 40 bee keepers a year are taken to hospital. 

Why do bee and wasps sting. 

Bees and wasps sting normally to protect nests and colonies. Lots of reasons can trigger or increase the likely hood of stings; this includes things like the weather, the season, the state of a colony, if a hive or nest is queen less, or brood less.

Guard bees are alerted as an animal approaches too closely to a hive or makes nervous or erratic movements. If hives are rocked or vibrated or a direct threat to an individual bee is identified it heightens the chances of a sting.  Strong odours, pheromones, dark colours and carbon dioxide from mammals also increase the chances of a sting. 

Guard bees intent on stinging, rear up with wings spread and mandibles' open.

Alerted bees may leave nest searching for a predator. 

At first bees start buzzing and irritating-annoying the predator. Bees may continue and finally head butt the predator to ward them away. Bee's will also burrow into hair and may pull or bite hair again to annoy and irritate the predator away. The bee or the wasp is going for rapid movement and is searching for the face and the breath and sweat will attract the bees.

Bee attempts to sting

Where clothes are more constricted the bee sting has a better chance of impaling you. Venom that has dried on clothes will attract other bees. It's important to keep the bee suit clean.

The sting is a modified ovipositor. Only the queen and the male bees do not have them. The sting is normally in a retracted state. It is enclosed in the 7th abdominal segment controlled by nerves.

One the sting has been deployed its takes for upto a minute or longer to inject all the venom. The venom is stored in a venom sac grown from day 3 - day 21 in the brood. The older a bee the less venomous they are.

An umbrella action sucks and pushes and pumps the venom. The bee sting pushes in deeper by pumping its muscles.

Venom is a clear liquid which tastes bitter and smells of ripe bananas 88% of it is made up of water. It also contains enzymes and phospholipids, Hyaluronidase and acid phosphates its these that are responsible for the allergic response. 

Venom contains mellitin about 52% of it is mellitin. It encourages the production of cortisol in the body as does Apamin and another core ingredient. The rest is a mixture of Adolapin, Phospholipids and Hyaluronidase and Histamine, which causes the allergic response.

The first sting is the main allergic contributor. It produces a local reaction, 

• fiery intense pain 
• immediate redness
• small pale raised area about 1 cm in diameter

Second and sub sequential stings.

• Central sting subsides but surrounding areas swell and increases slowly over several hours
• It may be gross where skin is loose. Primarily the face.
• Such swelling is not dangerous unless it affects the airway
• Itching is caused by histamine released, from the venom.
• There may be blistering and this can get infected if not protected 

Treatment of normal reactions

• Relive pain by cooling - via ice pack
• Give simple analgesic aspirin paracetamol
• If swelling after stings becomes a problem take antihistamine and hour before tending the bees eg Priton.

Bee keepers normally become desensitised to bee stings over time some even after having kept bee for a long period may get an allergic reaction. 

John suggested a book by Harry Riches - Medical aspects of Beekeeping for further reading.