57
By: Dr Ismah 1

Insect bites

  • Upload
    snich

  • View
    78

  • Download
    3

Embed Size (px)

Citation preview

Page 1: Insect bites

By: Dr Ismah

1

Page 2: Insect bites

0

1

2

3

4

5

6

Bee Centipide Scorpion

6 (75%)

1 1

Total: 8/101 cases2

Page 3: Insect bites

3

The 18-year-old from Des

Moines, Iowa, was stung for the

first time when she was only

4 when a bee sting on

her neck made it swell to

the size of a "balloon."

Page 4: Insect bites

1. History

2. Epidemiology

3. Bee?

4. Pathogenesis

5. Diagnosis

6. Management

7. Anaphylaxis

8. Prevention

4

Page 5: Insect bites

• The first reports of stinging insect

allergy came from the Middle East

thousands of years ago

5

Page 6: Insect bites

• 56.6 – 94.5% stung by Hymenoptera insect

at least once in live

• Fatal stings at least 40 cases each year in

USA and 16–38 cases in France.

6

Page 7: Insect bites

• Systemic allergic reactions up to 3% of

adults and 1% of children.

• In children about 60 % of systemic sting

reactions are mild, whereas in adults

respiratory or cardiovascular symptoms

occur in about 70 %.

• Children also have a better prognosis than

adults with respect to the risk of systemic

reactions to re-stings. 7

Page 8: Insect bites

• The name Hymenoptera is derived from

the Greek words "hymen" meaning

membrane and "ptera" meaning wings

8

Page 9: Insect bites

9

Page 10: Insect bites

10

Page 11: Insect bites

11

Page 12: Insect bites

12

Page 13: Insect bites

13

Page 14: Insect bites

• Honey bees are only capable of stinging a

person once.

• The honey bee is the only stinging insect that

leaves its stinger and venom sac in the skin of its

victim, due to the pointed configuration of the

stinger.

14

Page 15: Insect bites

15

Page 16: Insect bites

• Bumblebees rarely sting people because they

are non-aggressive and typically well

mannered

• They generally will sting only if provoked

• They nest in the ground or in piles of grass

clippings or wood

16

Page 17: Insect bites

• Wasps build honey-comb nests under the

eaves of a house, or in a tree, shrub or

under furniture.

• They tend to be less aggressive than

yellow jackets and hornets, and mostly

feed on insects and flower nectar.

17

Page 18: Insect bites

• They tend to be very aggressive insects,

and will often sting without provocation.

• They are commonly found around garbage

cans and picnic areas where food and

sugary drinks are abundant

18

Page 19: Insect bites

• These insects may be very aggressive,

and a sting may be provoked by a minor

disruption in their environment.

• Hornets look very much like yellow jackets

and can be difficult to distinguish

19

Page 20: Insect bites

• Bees release large amount of venom,

average 50–140 mcg/sting.

• Allergens constituting the venom include

• vasoactive amines,

• small polypeptides and enzymes,

• histamine, mast cell degranulating peptide,

• phospholipase A2 (PLA2), hyaluronidase,

• acid phosphatase and melittin

20

Page 21: Insect bites

• Venom sacs may contain up to more than 300

mcg of venom

• Wasp, which are capable of repeated stings,

generally inject less venom per sting

21

• 10 to 31 mcg of venom/sting

Bumble bees

• 1.7 to 3.1 mcg of venom/sting

Wasp

• 2.4 to 5.0 mcg of venom/sting

Yellow jacket wasp

Page 22: Insect bites

22

Allergic responses to stinging

1. Localized cutaneous reactions

2. Systemic anaphylaxis

Page 23: Insect bites

• Localized skin responses to biting insects

are caused primarily by vasoactive or irritant

materials derived from insect saliva, and rarely

occur from IgE-associated responses

• The majority of patients who experience

systemic reactions after Hymenoptera

stings have IgE-mediated

sensitivity to antigenic substances in the

venom.

23

Page 24: Insect bites

• History

• Clinical manifestation

• Investigation

24

Page 25: Insect bites

Categories

Local

Large local

Generalized cutaneous

Systemic

Toxic

Delayed

/late

25

Page 26: Insect bites

• Local: Insect bites are usually urticarial but may

be papular or vesicular, limited swelling <24 hrs

• Large local: an area of induration with a

diameter of 10 cm or more; which peaks

between 24 hours and 48 hours and then

subsides, may last for days

26

Page 27: Insect bites

27

Page 28: Insect bites

Generalized cutaneous reactions

• Typically progress within minutes and

include cutaneous symptoms of:

i. Urticaria

ii. Angioedema

iii. Pruritus

*beyond the site of the sting

28

Page 29: Insect bites

29

Page 30: Insect bites

30

Page 31: Insect bites

31

Page 32: Insect bites

• Rhabdomyolysis, acute renal failure, Guillain-

Barré syndrome, myasthenia gravis and

coagulopathy following multiple bee stings.

• Acute kidney injury (AKI) was seen in 21.0%

patients. Rhabdomyolysis was seen in 24.1%

patients, hemolysis in 19.2% patients, liver injury

in 30.1% patients, and coagulopathy in 22.5%

patients 7

• High creatinine level, shock, oliguria, and anemia

were risk factors for death 7

32

Page 33: Insect bites

• Toxic reaction: in mass bee envenomation due to the direct action of large amount of venom, not due to allergic reaction

i. Fever

ii. Malaise

iii. Vomiting

iv. Nausea

*due to the chemical properties of the venom in large doses.

In younger children less than 50 stings may prove lethal

Forty-eight patients died of organ injury following toxic reactions to the stings, whereas six died from anaphylactic shock from total of 1091 patients hospitalized 7 33

Page 34: Insect bites

• Delayed/late

i. Nephrotic syndrome

ii. Vasculitis

iii. Neuritis

iv. Encephalopathy

34

“Rarely a biphasic course is observed with an early onset,

an apparent recovery and a subsequent relapse after 4-24

hours”

Page 35: Insect bites

35

Page 36: Insect bites

• Blood test

• UFEME

• Prink skin testing, to identify venom

specific IgE

36

Page 37: Insect bites

37

Page 38: Insect bites

• Stingers should be removed promptly by

scraping, with caution not to squeeze the venom

sac because doing so could inject more venom

38

Page 39: Insect bites

• Hymenoptera VIT is highly effective (95-97%) in

decreasing the risk for severe anaphylaxis.

• The selection of patients for VIT depends on

several factors

• Price?

injection immunotherapy is less expensive than

sublingual immunotherapy with the cost per kit of

approximately $150 and about 3 or 4 kits required

over the time of the immunotherapy. Sublingual

treatment is between $500 and $1000 per year39

Page 40: Insect bites

40

SYMPTOMS AGESKIN TEST/IN VITRO

TEST

RISK OF

SYSTEMIC

REACTION IF

UNTREATED

(%)

VIT

RECOMMENDE

D

Large local

reactionAny Usually not indicated 4-10

Usually not

indicated

Generalized

cutaneous

reaction

≤16 yr Usually not indicated 9-10Usually not

indicated

≥17 yrPositive result 20 Yes

Negative result — No

Systemic

reaction Any

Positive resultChild: 40

Adult: 60-70

Yes

Negative result— Usually no

Page 41: Insect bites

41

Page 42: Insect bites

• Anaphylaxis is a severe, life threatening,

generalised or systemic hypersensitivity reaction.

• It is characterized by rapidly (minutes to hours)

developing life threatening airway and/or

breathing and /or circulation problems usually

associated with skin and/ or mucosa changes.

42

Page 43: Insect bites

Airways problem

Breathing problems

Circulation problems

43

• Airway swelling

• Hoarse voice

• Stridor

• Dyspnoea

• Wheeze

• Hypoxia

leading to

confusion

• Cyanosis

• Respirator

y arrest

• Shock

• Faintness

• Palpitation

s

• Cardiac

arrest

Page 44: Insect bites

• Previous severe reaction.

• History of increasingly severe reaction.

• History of asthma.

44

Page 45: Insect bites

• Therapies may include:

i. Oxygen

ii. Epinephrine

iii. Intravenous saline

iv. Steroids

v. Antihistamines

45

Page 46: Insect bites

46

Page 47: Insect bites

47

Page 48: Insect bites

48

*If hypotensive persist despite adequate fluid (CVP>10),

obtain echocardiogram and consider infusing noradrenaline

as well as adrenaline.

** Dose of intravenous corticosteroid should be equivalent to

1-2mg/kg/dose of methylprednisolone every 6 hours (prevent

biphasic reaction).

Page 49: Insect bites

• Oral prednisolone 1m/kg can be used in milder

case.

• Antihistamine are effective in relieving cutaneous

symptoms but may cause drowsiness and

hypotension.

• Continue observation for 6-24 hours depending

on severity of reaction because of the risk of

biphasic reaction and the wearing off of

adrenaline dose.

49

Page 50: Insect bites

• Prevention of further episodes.

• Education of patients and caregivers in the early

recognition and treatment of allergic reaction.

• An adrenaline auto injector should be prescribed

for those with history of severe reaction to food,

latex, insect sting, exercise and idiopathic

anaphylaxis and with risk factor like asthma.

50

Page 51: Insect bites

51

Page 52: Insect bites

• Frequent cleaning of surroundings, garbage cans

and decaying fruit makes it less attractive for

bees.

• Cracks in ceilings and walls should be sealed off

as they are potential nesting sites for colonies

• Best defence, when attacked by bees, is to run

to a place which can be sealed off, leaving the

bees outside 52

Page 53: Insect bites

53

Page 54: Insect bites

• While rescuing a victim of massive bee sting,

protective gear should be worn. Remove the

victim to a safe area, remove the stinger and

shift to hospital

• To kill bees, 1–3% foam or detergent water

mixture can be sprayed on the swarm of

attacking bees.

• Insecticide should be sprayed around the nests

at night, when they are less active 54

Page 55: Insect bites

• History of exposure

+Types of bees

• Clinical course

• Anaphylaxis

• Management

• Prevention

55

Page 56: Insect bites

1. Pediatric protocol 3rd ed

2. Insect Allergy by Prof. Dr. Saad S Al Ani, Senior Pediatric

Consultant, Khorfakkan hospital Sharjah, UAE

3. Allergy: Principles and Practice by Lieberman P, Elsevier Inc,

2009

4. General entomology, http://www.cals.ncsu.edu

5. Indian Guidelines and Protocols: Bee Sting

6. Diagnosis Of Hymenoptera Venom Allergy, Eaaci Position

Paper

7. Xie C, Xu S, Ding F, Xie M, Lv J, et al. (2013) Clinical

Features of Severe Wasp Sting Patients with Dominantly

Toxic Reaction: Analysis of 1091 Cases. PLoS ONE 8(12):

e83164. doi:10.1371/journal.pone.008316456

Page 57: Insect bites

57