INTRODUCTION  Avoidance measures for bee and wasp stings are critical in patients with hymenoptera allergy. However, no strong evidence

exists to support the usual recommendations1.

AIM    To evaluate risk factors for hymenoptera sting in a group of individuals with history of hymenoptera sting and to compare them with controls that

witnessed the event.  

CONCLUSIONS   In this sample, most of the stings occurred in rural environments, during outdoor activities and with the patients wearing dark-

colored clothing. Avoidance of hymenoptera stings can be life-saving in venom-allergic patients; however more studies are needed in order to

establish correct secondary prevention advice. REFERENCES  1-­‐  Greene  A,  Breisch  NL;  Avoidance  of  bee  and  wasp  s:ngs:  an  entomological  perspec:ve;  Curr  Opin  Allergy  Clin  Immunol.  2005  Aug;5(4):337-­‐41.    

Risk  factors  for  hymenoptera  s?ng  A  case-­‐control  study  

Diana Silva1,2, Natacha Santos1, Ana Margarida Pereira1, Ana Maria Pereira3, Luís Delgado1,2 , Alice Coimbra1 1 – Serviço Imunoalergologia, Hospital São João, EPE - Porto, Portugal;2 - Department of Immunology, Faculty of Medicine, University of Porto, Porto, Portugal; 3- Department of Clinical Pathology Service, Hospital São João, Porto

826  

22%  

17%  

8%  

8%  6%  

4%  

4%  

4%  

4%  

METHODS    This is a retrospective case-control study, including individuals with known history of hymenoptera stings (cases) and those that were at

the same place and at the same time, witnessed the event, but were not stung (controls).

RESULTS  

Case (n=61) Control (n=61) p value

Age years, median [IQR] 45 [28-55] 46[36;52] 0.268*

Female 28(46) 40(66) 0.073# Activity 0.219#

In motion 15(32) 27(49) Standing still 32(68) 28(51)

Clothing (lower body clothes) 0.625#

Short pants or dresses 13(29) 13(25) Long pants 32(71) 40(75)

Clothing (upper body clothes) 1.000#

Long sleeve shirt/coat 13(31) 17(32) Short sleeve shirt 29(69) 37(68)

Shoes 0.289#

Open shoes/ bare feet 22(46) 21(39)

Closed shoes 26(54) 33(61)

Color 0.687#

Dark clothing 24(53) 24(65)

Bright/White clothing 21(47) 13(35)

Use of perfume 6(10) 9(15) 0.453 IQR- interquartile range; * Wilcoxon test; # McNemar test

Table 1. Reported characteristics of the sting, environment and allergic reaction.

Table 2. Comparisons between cases and controls for potential risk

factors of hymenoptera stings.

Comparisons between cases and controls, as paired samples, were

performed with McNemar test or Wilcoxon test as appropriate

* No differences were detected between respondents and non-respondents.

Cases (n=61)

Stunged body part Head 22 (39)

Upper Limbs/torso 28 (50)

Lower Limbs 6 (11)

Multiple stings 7 (15)

Time of the day Morning (8-14h) 10 (19)

Afternoon (14-18h) 38 (70)

Evening (>18h) 6 (11)

Location Urban 8(14)

Rural 51(86)

Surroundings Indoor 4(9)

Outdoor 40(85)

Near a beehive 3(6)

Allergic reaction

Immediate (<1h) 53(96)

Delayed (>1h) 3(4)

Local symptoms 6 (10)

Systemic symptoms 55(90)

Mueller grading

system

I 8(13)

II 9(15)

III 21(34)

IV 17(28) All results are expressed in n(%), except if specified otherwize

*

9%

11%

2%

54%

24%

0% 10% 20% 30% 40% 50% 60%

Garbage

Animals

Beehive

Fruit trees

Green areas

Figure 1. Characterization of surroundings at the time of the sting.

In relation to this presentation, I declare that there are no conflicts of interest.

Those on venom immunotherapy (n=35)

had significantly more systemic

symptoms, severe reactions and

suffered more multiple stings.

Demographic and clinical characteristics of the selected cases (n=61) Age years, median [IQR] 42 [28-55] Rhinitis 12 (22)

Female 40 (47) Asthma 8 (15)

Insect Bee 36 (59) Time in years since the sting, median [IQR] 4.5 [2.0;8.0]

Wasp 15 (25) Beekeeper 6 (11)

Unknown 10 (16) Regular contact with beehives 12 (30)

Atopy to aeroallergens 9 (20) Venom Immunotherapy 35 (60) All results are expressed in n(%), except if specified otherwize