Wasps/Bees

Hymenoptera order includes wasps, bees, hornets and moskitoes. In our area, these insects are around mostly during Spring, Summer and early Autumn.

The most aggressive stinging insects are vespid wasps (including bald-faced hornets and other yellow jackets). All of these insects aggressively defend their nests.  The stings of most of these species can be quite painful.

Venom is injected when the insect stings. The active portion of the venom is a complex mixture of proteins, which causes severe  immediate local allergic reactions (IgE induced). In case of multiple stings, a toxic reaction may even occur.

There are 2 possible allergic reactions to wasp or bee venom:

• Immediate local reaction

Occurs in the following hours. May be largely spready and accompanied by edema (sometimes on a whole limb). Not a life-threatening reaction unless its location is unfortunate (i.e. mouth, neck) thus causing mecanical problems and potentially asphyxiation.

• Immediate allergic reaction (anaphylactic shock)

Occurs in the following minutes. The reaction is induced by specific IgE (antibodies) against the insect.

This is a life-threatening reaction.

Reaction is systemic: angioedema and urticaria (eventually in larynx), broncho-spasma (asthma), low blood pressure with fainting and cardiorespiratory failure. Paraesthesia, paresis, digestive trouble often come with the reaction.

Sometimes, only low blood pressure and fainting occur, with no other symptoms. Quincke’s edema (larynx edema) can occur and cause asphyxiation.

Such reactions are often repeatable, meaning a patient having suffered edema-urticaria the first time will probably have one the second time.

Unfortunately, for 15% of patients, reactions become more and more severe. Death occurrence due to severe reaction is also connected to age and cardio-respiratory pathologies.

Diagnosis of hymenoptera allergy

Patient’s reaction history, classified by seriousness and, if possible, identification of the insect having caused it, will enable initial diagnosis. This is later confirmed by skin prick-tests (standard and very reliable) and by a blood test calculating the amoung of specific IgE against these insects.

If the insect to be blamed for the reaction is not formally identified, prick-tests and blood tests will clarify which venom or venoms  the patient is allergic to.

Taking care of a sting if you are allergic

• Elementary precautions: choose light-coloured clothes covering all limbs and closed at the neck. Avoid perfume, spray insect-repellent on any bare skin, avoid eating outdoor, and avoid walking barefoot in Summer. Coloured and sweet flowers should be banned from gardens and balconies, especially near windows and doors. Hymenoptera traps can be used. Remember to close the car’s windows, and be extra careful when riding a bike/motorbike.
• Emergency: Allergic patient must always carry his emergency kit as well as his allergy passport.  In case of sting, he must sit down, tell people around him what is going on and get his adrenalin ready. Never suck up or incise the wound. If the stinger is still visible, you can pull it out carefully. Then take your cortisone and antihistaminic medicine.

Desensitization (allergic shots)

When allergic reaction is accompanied by bronchospasma and fainting, desensitization is a formal indication.

After 3 years of desensitization, skin prick-tests will be renewed. If still positive, treatment is to be continued another 2 years.

At the end of the 5 years of treatment, desentitization is complete, unless skin prick-tests still are positive and if there is a specific risk factor (i.e. bee-keeper, apiculturist).

Generally speaking, desensitization has excellent results and provides good protection.