insect bites and stings

Question 1

what is the mechanism of bite reaction from a mosquito

Answer 1

– Allergy to mosquito ‘saliva’ that inhibits blood clotting

Question 2

what is the allergic response to mosquito bites

Answer 2

• The immediate reaction
• IgE mediated response to saliva
• Histamine mediated
• Characteristic wheal and flare
• Later response
• Appears after 2-6 hours
• IgG and T cells?
• Erythematous papule

Question 3

what is skeeters syndrome

Answer 3

• Occurs within hours of bite
• May also have fever
• Various presentations
• Can be confused with cellulitis
• Usually days after a bite
  red circular rash

Question 4

what is midges

Answer 4

• Tend to swarm
• Maximum reaction often day after bite
• Similar to mosquito bite females feed to develop eggs
• Papules, wheals, and urticarial lesions
  black dots around hand

Question 5

what is the management for insect bites

Answer 5

cold compress
paracetamol
if it is a bee remove sting
if it is a tick remove tick
with a mosquito be aware reaction can come later

Question 6

how do antihistamines work

Answer 6

The primary mechanism of antihistamine action in the treatment of allergic diseases is believed to be competitive antagonism of histamine binding to cellular receptors

Question 7

why are some people drowsy after antihistamines

Answer 7

Drowsiness by working against a chemical produced by the central nervous system (histamine) the brain now thinks you are in sleep mode

Question 8

counselling points for insect bites

Answer 8

protective clothing
insecticide