Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Most stings arise because an insect perceives a threat to their colony.
Bees and wasps commonly sting because an intruder has neared the hive or
nest. Loud noises (such as lawn mowers), bright or dark colors, and certain
perfumes or perfumed body products may also encourage stings. Some types of
insect venom contain pheromones, which attract other members of the colony
and induce them to sting.
When bees or wasps sting an individual, they inject venom under the skin
of their victim.
Honey bees, including killer bees, have barbed stingers that
tear off when they try to fly away after stinging, so these bees die after
the sting and thus can sting only one time. In this case the stinger and
venom sac typically remain embedded in the skin of the victim.
hornets, yellow jackets, and wasps are able to sting multiple times, since
their stingers are smooth and can be easily withdrawn from the victim's
Bee and wasp venoms vary according to species but typically contain toxic
components as well as antigens that stimulate an immune response.
What are the symptoms of a bee or wasp sting?
Insect stings may produce four types of reactions, each with
characteristic symptoms as below:
Local reactions are the most common type of reaction to
a bee or wasp sting. Symptoms include pain, swelling, warmth, and redness at the
site of the sting. Itching may also be present. These symptoms begin immediately
following the sting and often last for only a few hours. Depending upon the type
of insect, the stinging apparatus may still be visible in the affected skin.
Large local reactions have a greater degree of swelling that can last for up to
a week, sometimes associated with
nausea and/or tiredness. These
reactions are not allergic reactions.
Systemic (body-wide) allergic reactions occur in people who have produced
a type of antibody known as IgE
antibody against the same insect venom as a result of a previous sting. Systemic
allergic reactions are estimated to occur in 0.3% to 3% of stings. Symptoms
include hives and flushing of the skin and difficulty breathing due to swelling of the
narrowing of the bronchial passages. The reaction may vary in severity from mild
skin hives to life-threatening reactions. The most severe immunologic reactions
are known as anaphylaxis and occur more commonly in males and in people under 20
years of age. In severe reactions, hypotension (low blood pressure), circulatory
disturbances, and breathing difficulty can
progress to fatal cardiorespiratory arrest. Most people who develop
anaphylactic reactions have experienced previous stings with few problems.
Once an individual has experienced an anaphylactic reaction, the risk of
having a recurrent episode is about 60%.
Toxic reactions are a direct result of toxins in the
venom rather than the body's immune response. Most often these are due to
multiple simultaneous stings that introduce an unusually large amount of venom
into the body. Symptoms can include
dizziness, and convulsions. Hives,
rash, and skin symptoms are
less common in toxic reactions than in allergic reactions. Because bee and
wasp venom are strong stimulants of the immune response, people who have
experienced toxic reactions may produce antibodies to the venom and be at
risk for future systemic anaphylactic reactions to stings.
Delayed reactions are uncommon and occur even days to weeks after the
sting. These reactions constitute less than 0.3% of all reactions to insect
stings. The individual's own medical history and condition may play a role
in determining whether delayed reactions occur. Symptoms can vary widely and
may include inflammation of the
brain (encephalitis), the nerves (neuritis), blood
vessels (vasculitis), or kidneys (nephritis) as well as
disturbances. Serum sickness is a
type of delayed reaction that occurs a week to 10 days after a sting and may
cause itching, rash, fever, joint pain, fatigue, and
swollen lymph nodes.