Drug allergy and anaphylaxis

Question 1

what are the 2 ways mast cells can be activated in drug allergy reactions?

Answer 1

Via immunoglobulins - IgE
Direct activation - aspirin, contrast media

Question 2

where can an allergy history be taken from?

Answer 2

patient
carer
GP
community pharmacist
care home
medical notes
summary care record

Question 3

how do you take a drug allergy history?

Answer 3

all current meds and recent changes including OTC and injections

generic name for drug suspected of causing reaction

exact signs, symptoms and severity of reaction

when reaction occurred

how long before reaction drug was taken

whether the allergy is a first hand recollection

Question 4

what 5 things should be documented on the drug chart about an allergy?

Answer 4

generic name of drug
relevant non-drug allergies
nature of reaction
signature
Date

Question 5

what are 5 allergic symptoms?

Answer 5

itch
urticaria
hypotension
angioedema
wheeze

Question 6

what are 4 rashes that can be caused by non-allergic drug reactions?

Answer 6

morbilliform rash (like measles)
Erythema multiform (urticarial)
fixed drug eruptions
photosensitivity

Question 7

what 4 antibiotics are betalactams?

Answer 7

penicillins
cephalosporins - cefalexin, cephotaxime
carbapenems - meropenem, impenem
monobactams - aztreonam

Question 8

what beta-lactam antibiotic is safe in penicillin allergy?

Answer 8

Aztreonam

Question 9

what beta lactams can be prescribed with caution in those with penicillin allergy?

Answer 9

3rd generation cephalosporins - cefazidime, ceftriaxone
carbapenems - Meropenem - 1% of penicillin allergies have allaergy to carbapenems

Question 10

How long should a patient be observed for after anaphylaxis?

Answer 10

6-12 hours

Question 11

what is the dose of adrenaline given to adults and children >12 in anaphylaxis?

Answer 11

500 micrograms IM

0.5ml of 1 in 1000

Question 12

what are 4 conditions that increase risk of drug allergy?

Answer 12

HIV
EBV
CMV
CF

Question 13

what medications may patients with chronic urticaria or mastocytosis be sensitive to?

Answer 13

NSAIDs
opioid analgesics

drugs with histamine releaseing properties liek atracurium

Question 14

what medications are high risk for allergies?

Answer 14

beta lactam antibiotics
neromuscular blocking agents
radiocontrast media
NSAIDs
High molecular weight starches

Question 15

are women or men more at risk of drug allergies?

Answer 15

women

Question 16

what are 7 medications that commonly cause allergic reactions?

Answer 16

chlorhexidine
opioids
Antimicrobials
NSAIDs
plasma expanders
muscle relaxants
radiocontrast media

Question 17

what are 4 ways allergies should be identified in hospital?

Answer 17

red wrist band
documentation on drug chart
documentation in notes
documentation in electronic system

Question 18

what antihistamine is usually used in mild allergic reactions?

Answer 18

Chlorphenamine

Mild = no evidence of systemic reaction

Question 19

what is the definition of anaphylaxis?

Answer 19

a serious systemic hypersensitivity reaction that us usually rapid onset and may cause death. Characterised by potentially life threatening compromise in airway breathing or circulation

Question 20

what scale can be used to assess the severity of allergic reaction?

Answer 20

Sampson severity score

Question 21

what would be a grade 1 sampson reaction?

Answer 21

localised pruritus, flushing urticaria, angioedema

oral pruritus, tingling or mild lip swelling

Question 22

what is a grade 3 sampson reaction?

Answer 22

grade 2 skin signs - pruritus, angioedema, urticaria

oral signs + repetitive emesis

rhinorrhoea, congestion, sensation of throat tightness or itch

tachycardia (increase >15 BPM)

change in activity + anxiety

Question 22

what would be a grade 2 sampson reaction?

Answer 22

generalised pruritus, flushing urticaria, angioedema

grade 1 signs + nausea/vomiting

nasal congestion/sneezing

change in activity leve

Question 22

what is stage 4 sampson reaction?

Answer 22

skin signs

Oral signs, vomiting + diarrhoea

congestion, throat tightness, barking cough, difficulty swallowing, cyanosis, wheeze, SOB

Dysarrythmia/mild hypotension

light headed, feeling of pending doom

Question 23

what is a stage 5 sampson score?

Answer 23

skin signs loss of bowel control respiratory arrest severe brady, hypotesion, cardiac arrest LOC

Question 24

what is the dose of adrenaline given in children aged 6-12 in anaphylaxis?

Answer 24

300 micrograms 0.3ml 1 in 1000

Question 25

what is the dose of adrenaline given in children 6 months to 6 years in anaphylaxis?

Answer 25

150 micrograms 0.15ml of 1 in 1000

Question 26

what is the dose of adrenaline given to children <6 months in anaphylaxis?

Answer 26

100-150 micrograms 0.1-0.15ml of 1 in 1000

Question 27

when should a second dose of adrenaline be given if needed?

Answer 27

after 5 minutes

Question 28

what medication can be given to treat skin symptoms of anaphylaxis once patient is stable?

Answer 28

non-sedating antihistamine e.g. certirizine

Question 29

what is the dose of certirizine for an adult or child over 12?

Answer 29

10mg OD PO

Question 30

what is the dose or certirizine for a child aged 2-5?

Answer 30

1.5mg BD PO

Question 31

what is the dose of certirizine for a child aged 6-11?

Answer 31

5mg BD PO

Question 32

what antihistamine can be given IV or IM?

Answer 32

chlorpheniramine

Question 33

what other medications can be given in anaphylaxis to help with breathing?

Answer 33

INH or IV salbutamol ipratropium, amiophylline, magnesium

Question 34

what are 2 complications of IV adrenaline?

Answer 34

life threatening arrhythmias hypertension

Question 35

what is the usual dose of adrenaline in an autoinjector for an adult?

Answer 35

300 micrograms

Question 36

what is the follow up for a patient after anaphylaxis?

Answer 36

Prednisolone for 3 days Non-sedating antihistamine for 3 days - as per trust guidelines Medical allert band Document allergy Communicate with GP warn patient is available over counter give info leaflet prescribed 2 adrenaline autoinjectors report drug reaction via yellow card scheme

Question 37

when should patient with anaphylaxis be referred to specialist?

Answer 37

all severe reactions - anaphylaxis, SJS Reactions during or after anaesthesia when future management may be complicated by unnecessary avoidance of medications

Question 38

what are the guidelines on use of adrenaline autoinjectors?

Answer 38

carry two at all times call ambulance after every use lie down and raise legs after administration do not leave alone

Question 39

what are the 3 adrenaline autoinjecters available in the uk?

Answer 39

epipen emerade jext

Question 40

when should mast cell tryptase samples be take?

Answer 40

ASAP after reaction 1-2 hours later - no longer than 4 hours later At 24 hours

Question 41

how long should patients be observed for after anaphylaxis?

Answer 41

6-12 hours - adults or >16 years