Allergy Conditions
Insect – Allergic Reactions to Honey Bee and Wasp Stings
Written by Dr Adrian Morris and updated by Prof. Paul Potter, Director Allergy Diagnostic and Clinical Research Unit, UCT Lung Institute, Cape Town. Tel: 021-406 6886.
Sponsored by LabSpec.
While everybody enjoys the outdoors and fun in the sun and water during the hot South African summer months, many insects of the order Hymenoptera, which include Honey Bee (Apis mellifera), the Yellow Jacket Wasp (Vespula germanica) and the Paper Wasp (Polistes emarginata) are very active and may sting more people in summer than in the winter months.
These social insects only sting in self-defence if disturbed, although the African Bee is known to be more aggressive than the other Honeybees in other countries.
The Honeybee is the only insect to leave a stinger behind. The female worker honeybee carries the barbed stinger and dies soon after discharging the sting. It is thus easy to identify the honeybee as the culprit whereas the wasp does not leave a stinger behind.
Honeybee venom allergy is much commoner in South Africa, whereas in Europe wasp stings are more common.
Clinical Features of Sting Allergy
Normally some redness and swelling will result from the sting, but this usually resolves in a few hours.
In the allergic individual, a more long lasting and severe reaction will occur. A mild reaction will include intense redness, swelling, itching and pain all occurring within minutes. More severe reactions include generalised swelling and itching, faintness, sweating, a pounding headache, stomach cramps or vomiting, a feel of impending doom, a tight chest or choking sensation with swelling of the throat and in extreme cases anaphylactic shock with death resulting.
However, if you are allergic to the venom of the sting of that species of insect, you will develop mild to life threateningly severe allergic reactions.
Life threatening reactions are more likely to occur in people who are already known to be very allergic to bee venom, older people with pre-existing heart and chest complaints, or with multiple stings.
Avoidance Measures
People allergic to bee and wasp stings should try to avoid being stung and stay away from areas that bees and wasps frequent e.g. open dustbins, uncovered cold drink cans etc. If a swarm of bees approach run for shelter as bees are slow fliers ans can normally be outrun. Remember that bees fly in straight lines between flower and hive, hence collision with unsuspecting individuals occurs. If a wasp or bee approaches, STAY STILL, do not try to swat the insect as this may frighten it! If it lands, gently try to blow it off the skin.
If stung, try to look for the barbed stinger in the case of a bee sting and carefully remove it by flicking it or scratching it out of the skin from the stinger sack. Stings to the head and neck are more dangerous.
Life threatening reactions are more likely to accur in people who are already known to be very allergic to bee venom, older people with pre-existing heart and chest complaints or with multiple stings.
When stung immediately apply ice or cold compresses to the sting site. If a swarm of bees approach – run for shelter as bees are slow fliers and can normally be outrun.
Keep an insecticide spray in the kitchen or car and always have a “bee cloth” handy to trap insects and prevent being stung. Certain allergic individuals seem more prone to bee stings and appear to
“attract” bees. Wasps and bees are drawn to flower fragrances and clothing with bright colours (white is safest), perfumes,fruit juices and eating fruit out of doors, hair tonics, suntan lotions and floral odours. Warn young children not to stick their fingers into flowers, as bees are often busy collecting pollen. Wear covered shoes and avoid walking barefoot on flowering fields or clover-covered lawns. Carefully shake out any clothing left on the ground. Cover dustbins and any foods out of doors. Do not mow lawns, trim hedges or prune trees in mid summer. Bees and wasps tend to frequent clover fields, picnic areas and soiled dirt bins in particular.
Never walk in orchards in blossom or flowering field especially not barefoot or in open shoes. Avoid walking barefoot or in open shoes. Avoid walking barefoot on clover covered lawns. Carefully shake out any cloting left on the ground. Cover dustbins and any food out of doors. Do not mow lawns, trim hedges or prune trees in mid summer. Bees and wasps tend to frequent clover fields, picnic areas and soiled dirtbins in particular.
If one comes across a bee hive, don’t disturb it – bee keepers will be glad to come and remove it. Wasp nests should have petrol or kerosene applied to them and destroyed.
Prophylactic Management
Patients who are prone to severe reactions to bee stings should carry an adrenalin injection with them for self administration. Others should carry antihistamine pills. All bee allergic patients should wear a Medic Alert bracelet.
Hyposensitisation injections (Specific Immunotherapy – SIT) used to treat severe bee and wasp sting allergies are most effective. These injections are carried out weekly initially, then 6 weekly for 3 to 5 years and confer 96% protection against bee stings.
Treatment
When stung, look immediately for the barbed stinger in the case of a bee sting and carefully remove it by flicking it or scratching it out of the skin with the fingernail or a pointed object. Don t squeeze it, as more venom will enter the skin from the stinger sack. Stings to the head and neck are more dangerous. Immediately apply ice or cold compresses to the sting site.
Allergy shots or Specific Immuno-Therapy (SIT) treats the actual cause of the allergy and not just the allergic symptoms. This series of injections must be given by an experienced doctor in a properly equipped surgery. Specific Immuno-Therapy against bee venom allergy has been proven to give 96% protection against bee sting allergy.
The Specific Immuno-Therapy Injections (1cm needle and into the fatty tissue of the upper arm, NOT into muscle) are given every seven to fourteen days (This schedule is moderately flexible, depending on your own lifestyle) initially and then every six to eight weeks for three to five years. This means that six to eight injections a year for bee SIT can possibly save your life. SIT is covered by Medical Aid schemes.
Emergency Treatment
Honey bee venom allergy is much commoner than wasp allergy in South Africa.
A tourniquet can be very useful if applied immediately and briefly to a limb, if stung, while one is getting adrenaline or antihistamines or steroids on board.
Applying ice to the sting will also reduce blood folow to the areas and spread of the venom.
Preloaded adrenalin syringes (Ana-Guard or Epipen) are available for emergency use. Three to six puffs of an adrenalin inhaler (Medihaler-Epi) will relieve chest tightness and swelling of the throat. With less severe reactions, antihistamines may be administered by injection or given orally. A rapidly acting antihistamine such as Phenergan is best. Cortisone is also very effective, but takes a few hours to act.
With less severe reactions, antihistamines may be administered by injection or given orally. A rapidly acting antihistamine such as Phenergan is best. Cortisone is also very effective, but takes a few hours to act. For a severe reaction, a tourniquet should be applied to the limb and adrenalin injections are required immediately; these measures are life saving. Preloaded adrenalin syringes are available for emergency use (for example Epipen ). Proper medical treatment should be sought immediately. Contact your medical practitioner for further information.