Source: Manual of Ambulatory Pediatrics 2010
SOAP Note – Allergic Response to Hymenoptera
ALLERGIC RESPONSE TO HYMENOPTERA
A local or systemic reaction to the sting of an insect, generally a bee, wasp, or hornet.
I. Etiology
A. Hypersensitivity is an IgE-mediated response. Generally an initial exposure is followed by re-exposure, and the re-challenge elicits the reaction.
B. Hymenoptera
1. Bee family: Bees and honey bees
2. Wasp family: Yellow jackets, wasps, and hornets
3. Ant family: Fire ants of southeastern United States (attack en masse)
II. Incidence
A. 90% of children experience a normal reaction of less than 2 inches in diameter and less than 24 hours in duration.
B. 10% of children will have a large local reaction greater than 2 inches in diameter and lasting up to 7 days.
C. Anaphylaxis occurs in 0.4% to 0.8% of the general population.
D. Approximately 50 deaths from stings occur in the United States every year. The sting of a bee, wasp, or yellow jacket is more apt to produce severe, immediate hypersensitivity reactions than any other insect.
III. Subjective data
A. History of bite or sting
B. Local reaction
1. Swelling and redness at site of sting
2. Intense local pain
C. Systemic reaction; may be a combination of the following:
1. Anxiety, initially
2. Nausea
3. Itching
4. Sneezing, coughing
5. Hives or frank angioedema, with various parts of skin swollen
6. Swelling of lips and throat
7. Difficulty swallowing
8. Difficulty breathing
9. Stridor
10. Respiratory compromise with ultimate collapse
11. Vertigo
IV. Objective data
A. Local reaction
1. Local wheal and flare reaction with central punctum
2. Edema around sting site
3. Normal reaction
a. Swelling less than 2 inches in diameter
b. Duration less than 24 hours
4. Large local reaction
a. Edema more than 2 inches in diameter
b. Duration 1 to 7 days
B. Systemic reaction: Signs of anaphylaxis; generally occur within 30 minutes
1. Anxiety
2. Urticaria
3. Dysphagia
4. Laryngeal edema
5. Bronchospasm
6. Dyspnea
7. Cyanosis
8. Drop in blood pressure and pulse
9. Voice changes
V. Assessment
A. Hymenoptera sting by history (honey bee, if the stinger is left intact)
B. Differential diagnosis of anaphylaxis
1. Vasopressor syncope: Self-limited, no pulmonary involvement, rarely occurs when child is prone, blood pressure and pulse do not drop, child rouses after breathing amyl nitrite
2. Cardiac failure
3. Anxiety attack
4. Penicillin allergy
5. Obstruction in laryngotracheobronchial tree
6. Aspiration of foreign body
VI. Plan
A. Normal local reaction
1. Remove stinger by scraping off. The protruding end contains the venom sac, and pinching or using forceps will cause more venom to be pumped into the wound.
2. Topical application of ice
3. Benadryl, 1 mg/kg, up to 50 mg
4. Calamine lotion
B. Large local reaction or multiple stings
1. Local measures as above
2. Prednisone, 1 mg/kg/d for 5 days may be helpful
C. Systemic reaction
1. Apply tourniquet proximal to sting on an extremity.
2. Remove stinger; shave off stinger of honey bee (has reverse serrations).
TABLE 2–1 Epinephrine 1:1000 Dosage Table
KILOS POUNDS DOSAGE (ML)
10 22 0.1
15 33 0.15
20 44 0.2
25 55 0.25
30 and over 66 0.3
3. Administer epinephrine 1:1000, 0.01 mL/kg SC (maximum
0.3 mL); rub. Repeat in 15 to 30 minutes (see Table 2-1)
4. Benadryl, 1 mg/kg, up to 50 mg
a. Antihistamines should be used as an adjunct to epinephrine to block the effects of histamine on the receptor sites.
b. Antihistamines do not prevent bronchoconstriction; their greatest benefit is in blocking reaction of mucous membrane and skin.
5. Transport patient immediately to emergency room.
6. Refer patient to allergist for testing and possible immunotherapy.
7. Order EpiPen, and instruct patient or parent in its use.
a. EpiPen for patients 30 kg and over
b. EpiPen Jr. for patients 15 kg and over
c. Use trainer pen for instruction
8. Order rapid-acting antihistamine: Zyrtec (syrup 1 mg/mL, chewables 5 mg and 10 mg, tablets 5 mg and 10 mg)
a. 0.25 mg/kg: less than 2 years of age
b. 2.5–5 mg: 2–6 years of age
c. 5–10 mg: More than 6 years of age
VII. Education
A. Do not wear perfumes, hair spray, aftershave, and so forth when outside.
B. Wear neutral colors; flowery prints are apt to attract bees.
C. Do not walk barefoot outside. Yellow jackets, the most aggressive hymenoptera, nest in the ground.
D. Avoid flower beds, playgrounds, picnic areas, and trash or garbage disposal areas.
E. No insect repellent is available that repels stinging insects.
F. Do not run or engage in physical activity after a sting.
G. The honey bee stinger has reverse serrations and leaves its stinger in the skin with the venom sac attached to it. The venom sac continues to eject venom and will empty out completely if compressed. Do not squeeze it; instead, scrape or shave the stinger off.
H. Wasps and yellow jackets retain their stingers and may sting repeatedly.
I. 70% of deaths due to hymenoptera are caused by airway edema or respiratory compromise.
J. 85% of children who go into anaphylactic shock do so within the first 15 to 30 minutes of exposure.
K. Anaphylaxis has occurred as late as 6 hours following exposure, but this is highly unusual.
L. Steroids do not help against the initial insult but will help against a delayed recurrence after the initial treatment.
M. Skin testing for allergy may yield a false-negative result if done too soon after treatment for a sting; wait 3 to 4 weeks after a sting before doing such testing.
N. Immunotherapy reduces risk of life-threatening complications from 60% to less than 5%.
O. EpiPen spring-loaded syringe contains epinephrine in a premeasured dose. EpiPen delivers 0.30 mg (in patients >30 kg) and EpiPen Jr. delivers 0.15 mg (in patients >15 kg) of epinephrine.
P. Administer EpiPen into anterolateral aspect of thigh—through clothing if necessary.
Q. Parents should notify school, day care, camp, and other caretakers of reaction and have EpiPen available for child at all times.
R. Child should wear a MEDIC ALERT bracelet.
VIII. Follow-up
A. Contact after discharge from hospital to ensure that parent or child has made appointment with allergist for testing.
IX. Complications
A. Anaphylaxis following rechallenge
B. Delayed systemic reaction
X. Consultation/referral
A. Refer any patient who has had an immediate systemic reaction to allergist.
B. Consult with allergist on any patient who has had a large local reaction.