First Aid, Chapter 7 Hypersensitivity Disorders, Stinging Insect Allergy Flashcards Preview

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Flashcards in First Aid, Chapter 7 Hypersensitivity Disorders, Stinging Insect Allergy Deck (47)
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1
Q

What are the families of hymenoptera and any subfamilies in the group? What are the species in each group?

A

Family Apidae, Family Vespidae (subfamily vespinase, subfamily polistinae), Family Formicidae

2
Q

What are the species within family apidae?

A

Apis Mellifera (Honeybee), African-European Hybrid Bees (Killer Bee), and Bombus Spp (Bumblebee)

3
Q

What are the subfamilies and species within family vespidae?

A
  • Subfamily vespinae: species bespula (yellow jacket), dolichovespula arenaria and D. maculata (yellow hornet and white-faced hornets).
  • Subfamily Polistinae: polistes spp (paper wasp)
4
Q

What is the species in family formicidae?

A

-Solenopsis invicta (imported fire ant)

5
Q

What is the species Apis Mellifera commonly called? What is it used for? Describe its next. How aggressive is it? What happens to the sting? What family does it belong to?

A

Apis Mellifera (Honeybee)—Used commercially for honey production and pollination; beeswax nest with numerous vertical combs (Figure 7-8A); not aggressive, and only females will sting when provoked; barbed stinger that remains in victim’s skin, killing the insect. Family Apidae.

6
Q

What is the killer bee’s species name? Where did it come from? What other species is its allergen protein the same as? How aggressive is it? What family does it belong to?

A

African–European Hybrid Bees (Killer Bee—Escaped from a lab in Brazil in 1957 and have gradually migrated into the southern US. Similar to domestic honeybees and deliver identical allergen protein when it stings; however, they have a tendency to swarm with little provocation and sting in large numbers, causing a toxic reaction that can be fatal. Their aggressive nature has earned them the title “killer bees.” Family Apidae.

7
Q

What is the bumblebee’s species? Where are its nests and what are they made of? How aggressive are they? Is avoidance difficult? What family does it belong to?

A

Bombus Spp (Bumblebee)—Subterranean or concealed nests made up of loose fibrous material; not aggressive but will sting when nests are disturbed; attack is loud, and slow so avoidance is fairly easy. Family apidae.

8
Q

What are the nests of subfamily vespinae made of? What happens to their sting?

A

Multilayered paper nests made of masticated wood. Can sting repeatedly without losing sting apparatus.

9
Q

What is the name of the yellow jackets species? Where are they found? Are they aggressive? Where are the nests found?

A

Vespula spp. (yellow jacket): Picnic and trash can scavengers; highly aggressive, especially in summer and autumn when larger populations compete for food supplies; often sting for no apparent reason; nests found in concealed locations, either underground, in wall cavities, or decaying logs.

10
Q

What species of hymenoptera is most responsible for human stings?

A

vespula (yellow jacket).

11
Q

What are the species names of the yellow hornet and white-face hornets? Where is the next found? What sets off their defensive stinging behavior?

A

Dolichovespula arenaria and D. maculata (yellow hornet and white-faced hornets): Aerial-nesting yellow hornets found in North America but not Europe; nests found around human dwellings; sensitivity to vibrations sets off their defensive sting behavior.

12
Q

What hymenoptera species is frequently found around garbage cans or food?

A

Yellow Jacket

13
Q

What is the species name of the paper wasp? What is the subfamily? Describe its nest. Where are the nests found. Are they aggressive?

A

Subfamily Polistinae—Polistes spp. (paper wasp): Nest constructed of a single layer of open cells (or comb) that are found on eaves or window sills of homes (Figure 7-8C). Narrow “wasp waist” and dangling legs when in flight; less aggressive, but can sting repeatedly without losing sting apparatus.

14
Q

What is the species and family name of the fire ant? Where are its nests found? Where are they located? Are they aggressive? How do they sting? Describe the resultant skin manifestation of a sting.

A
Family Formicidae  
Solenopsis invicta (Imported Fire Ant). Large subterranean nests. Widespread in the southeastern US. Are aggressive and have a true sting apparatus; they anchor by their mandibles and pivot to administer multiple stings that develop into characteristic sterile pustule at site within 24 hours after sting. Arrived in Mobile, Alabama, in the 1940s and have slowly spread, adapting to colder climates, with nests found as far north as Maryland.
15
Q

What is the prevalence of systemic reactionsto stings? How many fatal reactions are there annually? What percentage of those occur in people with no prior history of an allergic reaction to stings?

A

Systemic reactions reported in 3% of adults and 1% of children; approximately 30–50 fatal stings occur per year in the US, with half of those occurring in people with no prior history of allergic reaction to sting.

16
Q

Other than normal reactions, large local reactions, and systemic reactions to insect stings, what other types of reactions are possible?

A

Toxic, serum sickness, neuropathy, and rhabdomyolysis.

17
Q

Is the skin prick always done before ID in venom testing? When is it a good idea? At what concentration?

A

The venom skin prick testing is not always done prior to intradermal testing, although it is reasonable in patients with a history of severe anaphylaxis who may be extremely sensitive to venom (1.0–100 μg/mL).

18
Q

What is the starting dose of venom ID testing? What are the next doses? When is it completed?

A

Intradermal technique begins with concentrations between 0.001–0.01 μg/mL and proceeds by 10-fold increments until a postive result or a maximum concentration of 1 μg/mL is reached.

19
Q

False-positive (irritant) results to intradermal testing are more likely above what venom concentration?

A

Concentrations > 1 μg/mL, therefore not recommended for diagnostic purposes.

20
Q

How long should you wait after a sting to do venom testing? Why?

A

Negative skin testing in the days or weeks after a sting reaction may be attributed to a refractory period of “anergy.” For these patients, the skin test should be repeated after 4–6 weeks.

21
Q

With a patient with a strong history of severe systemic reaction to insect sting, what should you do after negative skin testing? Why?

A

Skin tests are negative in up to 10% of persons found to have venom-specific IgE.

22
Q

For venom testing, what percentage of patients are serologic tests negative in skin test positive patients?

A

Serologic testing is negative in up to 20% of skin test-positive patients.

23
Q

What should you do if your suspicion is high of systemic reaction to venom but in vitro and skin testing is negative?

A

Repeat skin testing.

24
Q

If severe hypotension occurs after a hymenoptera sting, what key blood test should be done?

A

Tryptase level.

25
Q

What is the chance of systemic reaction on subsequent stings in a patient with prior history of systemic reaction with evidence of serum-specific IgE? Is a negative sting challenge conclusive?

A

30-60%, therefore negative sting challenge has limited clinical significance.

26
Q

Does the degree of skin test sensitivity correlate to degree of sting reaction?

A

No.

27
Q

What stinging species can whole body extracts be used for diagnosis and treatment? Which species can it not be used in?

A

Whole-body extracts (WBE) for flying hymenoptera contain little or no venom and are ineffective for diagnosis or treatment of venom allergy, unlike imported fire ant venom, in which WBE is routinely used for diagnosis and treatment of imported fire ant allergy.

28
Q

What is the treatment choice to prevent further systemic reactions to insect stings? When is it indicated?

A

Venom immunotherapy. It is indicated for patients with clinical history of anaphylaxis to insect sting and evidence of venom-specific IgE with skin test or serologic testing.

29
Q

How safe is venom immunotherapy?

A

Fifty percent of patients have large local reactions and 5–15% have systemic symptoms during the build-up phase. The majority of reactions are mild, and

30
Q

How effective is venom immunotherapy?

A

Seventy-five percent to 95% efficacy rate with maintenance dose of 100 μg of venom (for single antigen) or 300 μg of venom (for mixed vespids).

31
Q

What is the risk of a systemic reaction to a sting in a patient with no reaction history?

A

1-3%

32
Q

What is the risk of a systemic reaction to a sting in a patient with a prior history of large local reaction? Is skin testing or VIT indicated?

A

5-10%. No skin testing or VIT recommended.

33
Q

What is the risk of a systemic reaction to a sting in a child less than age 16 with a history of urticaria/angioedema to stings and positive skin testing? Should they get VIT?

A

10% risk of systemic reaction. No VIT recommended.

34
Q

What is the risk of a systemic reaction to a sting in a child greater than age 16 or adult with a history of urticaria/angioedema to stings? Should they get VIT?

A

20%, Yes get VIT.

35
Q

What is the risk of systemic reaction to a sting in a child with a history of positive skin testing and anaphylaxis to a sting? Should they get VIT?

A

40%, yes get VIT.

36
Q

What is the risk of systemic reaction to a sting in an adult with a history of positive skin testing and anaphylaxis to a sting? Should they get VIT?

A

60%, yes VIT.

37
Q

What is the risk of systemic reaction to a sting after receiving VIT for 5 years? Should those patients continue to carry epi?

A

Patients who have received VIT for at least 5 years have ~10% chance of systemic reaction with each sting after stopping treatment. Patients should therefore continue to have epinephrine available even after discontinuing VIT (general population risk ~3%).

38
Q

Where are the allergens in biting insects found?

A

In their saliva.

39
Q

What is the standard mainteance dose of venom for a single antigen? What is the max dose? What is the dose for mixed vespids? Is the risk of a systemic reaction higher for rush regimens?

A

Standard maintenance dose is 100 μg of venom (for single antigen), but can be increased to a 200 μg maintenance dose if treatment fails. For mixed vespids, a standard maintenance dose of 300 μg is used. Schedules are highly variable, and risk of systemic reactions with rush regimens are not much higher than traditional regimens.

40
Q

What is imported fire ant extract composed of? What is the maintenance dose?

A

Imported fire ant extract is composed of WBE and has a maintenance dose of 0.5 mL of a 1:10 to 1:200 wt/vol extract given monthly.

41
Q

When should VIT be discontinued? Who should it be continued it indefinitely?

A

General recommendation is to continue VIT for at least 3–5 years. Those patients with a very severe initial reaction, patients with systemic reactions to injection or sting while on therapy, or those with honeybee allergy might need to continue VIT indefinitely.

42
Q

What 4 biting insects can cause reactions?

A

1) Kissing bug (triatoma)
2) Mosquito (Culicidae)
3) Horsefly and Deerfly (Tabanidae)
4) Asian Lady Beetle (Harmonia Axyridis)

43
Q

What is the most common cause of biting insect systemic reactions? What is the most common presentation of a bite with this species? Can IT be done?

A

Kissing bug (Triatoma). Most often a nocturnal painless bite that causes an erythematous urticarial nodule or plaque. Relevant allergens are salivary gland proteins; small studies have shown benefit with immunotherapy with salivary gland extracts.

44
Q

Is anaphylaxis to mosquitos common? What is Skeeter syndrome and what is it due to? Who is it more common in? Can mosquito extracts be used therapeutically? What is the treatment of large local reactions?

A

—Anaphylaxis to mosquito bites is rarely reported. Large local reactions are more common in children, may be accompanied by fever (skeeter syndrome), and are due to sensitization to mosquito salivary secretions; mosquito extracts are not approved for therapeutic use. Antihistamines can be used to relieve large local reactions from mosquito bites.

45
Q

What is a horsefly or deerfly bite like? Is anaphlaxis common?

A

Large, blood-sucking flies that inflict painful bites; anaphylaxis following bites has rarely been reported.

46
Q

What symptoms do sensitized patients have to asian lady beetle bites? What does the asian lady beetle cross-react with?

A

Bites in sensitized individuals have been associated with rhinitis, urticaria, and asthma symptoms; considered an indoor allergen and has cross-reactivity with cockroach on skin testing.

47
Q

A 6-year-old boy camping in Texas awakens with diffuse hives, shortness of breath, and wheezing after a painless bug bite. What biting insect would you be most concerned about?

A

Triatoma.

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