11.05 Hymenoptera (Bee, Wasp, Hornet) Envenomation
==================================================

agk's Library of Common Simple Emergencies

Presentation
------------

Sometimes a patient comes to a hospital emerg- 
ency department immediately after a painful 
sting because he is alarmed at the intensity of 
the pain or worried about developing a serious 
life threatening reaction. Sometimes he seeks 
help the next day because of swelling, redness, 
and itching. Parents may not be aware that 
their child was stung by a bee and be concerned 
only about the local swelling. Erythema soon 
after the sting, with varying degrees of local- 
ized edema, develops. Often there is a central 
punctate discoloration at the site of the 
sting, or, rarely, a stinger may be protruding. 
A delayed hypersensitivity reaction will 
produce varying degrees of edema which can be 
quite dramatic when present on the face. 
Tenderness and, occasionally, ascending 
lymphangitis can occur.

What to do:
-----------

- Scrape away the stinger with the back edge of 
    a scalpel blade or a long fingernail.
- Examine the patient for any signs of an 
    immediate, systemic, allergic reaction 
    (anaphylaxis), such as decreased blood 
    pressure, generalized urticaria or 
    erythema, or wheezing.
- Apply a cold pack to an acute sting to give 
    pain relief and reduce swelling.
- Observe the patient with an acute sting for 
    approximately an hour to watch for the rare 
    anaphylaxis.
- Reassure patient who has come in after 12-24 
    hours that anaphylaxis is no longer a 
    problem.
- Prescribe hydroxyzine (Atarax) 50mg qid for 
    itching.
- If an ascending lymphangitis is present, 
    treat the patient with an appropriate 
    antibiotic for 10 days (e.g., cephadryl 
    (Duricef) lgm qd, cephalexin 500mg tid, 
    dicloxacillin 500mg qid)
- If an extremity is involved, have the patient 
    keep it elevated and instruct him that the 
    swelling may worsen if the hand or foot is 
    held in a dependent position. This swelling 
    may continue for several days. Severe hand 
    swelling may be prevented or reduced by 
    placing the patient in a splint and 
    compression dressing. Promptly [remove any 
    rings] in cases of hand stings.

What not to do:
---------------

- Do not belittle the patient's complaint or 
    make him feel guilty about his visit.
- Do not send the patient with an acute sting 
    out of the ED less than one hour after the 
    sting.
- Do not apply heat, even if an infection is 
    suspected---the swelling and discomfort 
    will worsen.

Discussion
----------

Bee stings are very painful and frightening. 
There are many misconceptions about the danger 
of bee stings, and many patients have been 
instructed unnecessarily to report to an ED 
immediately after being stung. Many of these 
people have only suffered localized hyper- 
sensitivity reactions in the past and are not 
at a significantly greater risk than the 
general public for developing anaphylaxis. 
Besides the immediate relief of pain for the 
acute sting, we have little more than reassur- 
ance to offer these patients. Although it is 
most prudent to treat an ascending lymphangitis 
with an antibiotic, it should be realized that 
after a bee sting the resultant local 
cellulitis and lymphangitis is usually a 
chemically mediated inflammatory reaction. 
Histamine is one of many components of 
hymenoptera venom: antihistamines may benefit 
the sting victim.

References
----------

- Visscher PK, Vetter RS, Camazine S: Removing 
    bee stings. *Lancet* 1996;348:301--302.

 ----------------------------------------------------
 from Buttaravoli & Stair: COMMON SIMPLE EMERGENCIES
 Longwood Information LLC 4822 Quebec St NW Wash DC
 1.202.237.0971 fax 1.202.244.8393 electra@clark.net
 ----------------------------------------------------