wk 2 2 Cutaneous Drug Eruptions

Question 1

hypersensitivity type I (anaphylactic) may lead to what effect on skin

Answer 1

uticaria

Question 2

type 2 (cytotoxic) leads to what effect on skin

Answer 2

blistering (pemphigus/pemphigoid - look like these, auto-iimmune blistering)

Question 3

ype 3 (immune-complex) can cause what efrct on skin

Answer 3

purpura/rash

Question 4

type 4 (delayed) causes what effect on skin

Answer 4

erythema/rash

Question 5

in immune reactions, there is not a dose-dependant for reaction

Answer 5

true

Question 6

examples of non-immunological reactions in skin

Answer 6

eczema
drug induced alopecia
phototoxicity
skin erosion (topical 5-flurouracil) 
atrophy 
psoriasis
pigmentation 
cheilitis, xerosis 
(can be dose dependent)

Question 7

drug induced skin condition most typically present as

Answer 7

morbilliform 
exanthematous (symmetrical) 
uticaria 
pigmentation 
itch/pain
photosensitivity
(blistering more rare)

Question 8

risk factors for drug eruptions

Answer 8

age - young adults>infants, elderly

gender
-females

genetics

concomitant disease

• Viral INfections
• CF

Immune status

• prev drug reaction
• positive skin test

Question 9

B-lactam compounds and NSAIDS are more likely to cause drug eruptions

Answer 9

true

High mol. weight/ hapten-forming drug also

Question 10

which route is likely to cause skin eruptions

Answer 10

topical

Question 11

most common type of drug skin eruption

Answer 11

exanthematous drug eruptioons

Question 12

exanthematous is a type __ hypersensitivity reaction

Answer 12

4

Question 13

t/f exanthematous are mild and self limiting

Answer 13

true

Question 14

pruritis is unlikely with exanthematous

Answer 14

false
v common
mild fever also common

Question 15

time frame from taking first drug to developing skin conditions

Answer 15

4-21d

Question 16

exanthematous skin eruptions can be indicated by

Answer 16

skin pain 
oedema 
involvement of mucous membrane and face
high feveer ( >38.5)
Dyspnoea, wheezing 
widespread confluent erythema  
lymphadenopathy, arthalgia

Question 17

examples of dugs associated with exanthematous eruptions

Answer 17

penicillins
erythromycin 
allopurinol 
NSAIDS
chloramphenicol 
anti-epileptics (carbamazepine, phenytoin) 
sulphonamides 
streptomycin

Question 18

uticarial drug reactions are usually an ____ __ ___ reactioin

Answer 18

immediate IgE mediated

can also be direct release of inflam mediators from mast cells (aspirin, opiates,NSAIDS,muscle relaxants, Vanco, Quinolones)

Question 19

t/f uticaria is blanching and mobile

Answer 19

true

gone within 24hrs

Question 20

if longer than 24hrs, consider

Answer 20

uticaria vasculitis

Question 21

pustular/ bullous drug eruptions can occur when using

Answer 21

glucocorticoids
androgens, lithium (no blackheads) , isoniazid, phenytoiin
(these cause acneiform)

Question 22

acute generalised exanthematous pustylosis (AGEP) can occur when using

Answer 22

antibiotics
Ca blockers
Antimalarials

Question 23

pemphigoid

Answer 23

auto-immune blistering disease

Question 24

drug-induced bullous pemphigoid can occur due to 3

Answer 24

ace inhibitors
penicillin
furosemide

Question 25

vancomycin can trigger linear IgA disease t.f

Answer 25

true

Question 26

fixed drug eruptions can be described as

Answer 26

well demarcated round plaques

Question 27

fixed drug eruptions are usually not painful

Answer 27

false | red, painful

Question 28

fixed drug eruptions always occur in the same spot

Answer 28

true

Question 29

4 severe cutaneous drug reavtions include

Answer 29

stevens-johnson syndrome (SJS) toxic epidermal necrolysis (TEN) drug reaction with eosinophilia and systemic symptoms (DRESS) acute generalised exanthematous pustulosis (AGEP)

Question 30

DRESS causes

Answer 30

high fever, usually on infections ward

Question 31

TEN patients require treatment as if they are a

Answer 31

burns patient

Question 32

explain phototoxicity

Answer 32

drug in skin, absoorbs light (UVA), produces oxygen radicals leading to damage

Question 33

t/f phototoxic cutaneous drug reactions is an immunological skin reaction

Answer 33

false

Question 34

presentation of skin phototoxicity

Answer 34

``` immediate prickling with delayed erythema/pigmentation (chlorpromazine, amiodarone) exaggerated sunburn (quinine, thiazides, demeclocycline) exposed telangiectasia (Ca blockers) (broken blood vesels) incr skin fragility (nalidixic acid, tetra naproxen, amiodarone) ```

Question 35

important qs in histoyry

Answer 35

``` detailed description of reaction timing of onset/ prev exposure why on drug comprehensive drug history prev history of drug reaction ```

Question 36

common drugs causing cutaneous eruptions

Answer 36

doxy amiodarone (acneiform) chlorpromazine (sunburn) quinine (pigmentation, itching)

Question 37

investiigations

Answer 37

history/physical super important phototesting biopsy patch and photopatch tests (type IV) skin prick tests for specific drugs (for type I) skin testing not indicated for serum sickness reaction (typeIII) or for T cell mediated (TypeIV) (potentially trigger SJS,TEN,DRESS)

Question 38

management for drug eruptions

Answer 38

discontinue drug if possible/ use alternative topical corticosteroids may be useful antihistamines if Type I/itch allergy bracelets drug adverse effects - reported via yellow card scheme