Eczemas and Allergic Skin Diseases 2 (Adverse Drug Reactions)

Question 1

Erythematous eruptions (abrupt onset)

Answer 1

most mild, can be severe and life threatening in some cases

Question 2

Drug eruptions can ____ any inflammatory skin condition

Answer 2

mimic

“Developing a rash while taking a medication is a drug eruption until proven otherwise.”

Question 3

Most erythematous eruptions in children are?

Answer 3

viral exanthems

Question 4

Most erythematous eruptions in adults are?

Answer 4

drug eruptions

Question 5

Simple drug eruptions

Answer 5

rash (skin) only; antibiotics mostly cause these; no lab findings

Question 6

Complex drug eruptions

Answer 6

constitutional symptoms; sulfonamides/allopurinol/anticonvulsants; show abnormal labs (liver and kidney function)

Question 7

Exanthematous drug eruptions

Answer 7

these are 90% of cases; mixed I and IV; pt’s history is important
take up to 1 wk on first exposure, 1-2 days if previously exposed
immediately withdraw drug, topical steroids

Question 8

Urticaria (hives)

Answer 8

pruritic skin eruption, with blanchable wheals in varying sizes
ind. lesions resolve in 48 hours, while new ones are developing

Question 9

Angioedema

Answer 9

swelling of subcut. tissue (usually near eyes and mouth) and mucosa of GI and respt. tract
resolves in 2-4 days

Question 10

Anaphylaxis

Answer 10

severe allergic reaction
laryngospasm->airway obstruction/vascular collapse->hypotension
occurs within 1 hr of exposure

Question 11

Pathophysiology of urticaria and angioedema may be an _______ or _______ mechanism

Answer 11

allergic; non allergic

not limited to a drug reaction

Question 12

Various causes of Urticaria and/or Angioedema

Answer 12

drugs, insects, foods, parasitic infections, latex, aeroallergens, pressure

Question 13

Physical Uticaria

Answer 13

resolves in 2 hours (stress, anxiety, etc)

Question 14

Acute Uticaria

Answer 14

ind. lesions resolve in 24-48 hrs, reaction resolves <6 wks with no confounding symp.
what you think of when you think of an allergic reaction
RAST test appropriate

Question 15

Chronic Uticaria

Answer 15

ind. lesions resolve in 24-48 hrs, reaction resolves >6 wks with no confounding symp.
possibly autoimmune disorder
*refer case

Question 16

Uticaria with vasculitis

Answer 16

ind. lesions last longer than 48 hrs and have confounding symp. such as hives, fever, and vasculitis
* refer case

Question 17

Angioedema without uticaria what is likely cause?

Answer 17

ACE inhibitors

Question 18

No history of ACE inhibitors what is angioedema without uticaria likely caused by?

Answer 18

Hereditary angioedema (HAE)

Question 19

Blood test to identify hereditary angioedema

Answer 19

C’1 Esterase Inhibitory (C’1 INH)

Question 20

Antihistamines: H1 blockers

Answer 20

block histamine receptors in skin and vasculature

Question 21

Antihistamines: H2 blockers

Answer 21

block histamine receptors in parietal cells

Question 22

Erythema Multiforme (EM)

Answer 22

cutaneous reaction to antigenic stimuli; sometimes as drug reaction but usually reaction to herpes simplex virus

Question 23

Erythema Multiforme: Minor

Answer 23

target lesions and vesicles on extremities. little mucous membrane involvement, no systemic symp

Question 24

Erythema Multiforme: Major

Answer 24

target lesions with vesicles and bullae (blisters) on extremities also involving mucous membranes, systematic symp.

Emergency-may have detachment of large sheets of skin

Question 25

EM Major may have a positive ___________.

Answer 25

Nikolsky sign or phenomenon (epidermis dislodged from dermis)

Question 26

EM that results as a drug reaction is usually EM ____?

Answer 26

Major

Question 27

EM major treated with?

Answer 27

oral corticosteroids

Question 28

EM minor treated with?

Answer 28

antivirals

Question 29

Steven-Johnsons Syndrome

Answer 29

acute, life threatening reaction to drugs that result in extensive necrosis and detachment of epidermis
<10% epidermal detachment
10-30% overlapping SJS and TEN

Question 30

Toxic Epidermal Necrolysis (TEN)

Answer 30

same as Steven Johnsons Syndrome, just more severe

>30% epidermal detachment

Question 31

Average mortality for SJS is

Answer 31

5-10%

Question 32

Average mortality for TEN is

Answer 32

30%

Question 33

SJS and TEN have what attributes?

Answer 33

target-like lesions or diffuse erythema that progress to necrosis and epidermal detachment; may occur over a few hours to days, severely painful, fever, tachycardia

Question 34

SJS and TEN treatment?

Answer 34

discontinue drug!! prevent recurrence by never administering drug again
hospitalize and treat like burn pt. with fluids and electrolytes
avoid debridement; treat complicating infections