Drug-Induced Dermatology

Question 1

What should you always ask a patient when they come into the pharmacy and they have a rash?

Answer 1

Do you have a fever?

Question 2

Four categories of cutaneous drug eruptions

Answer 2

Exanthematous, urticarial, blistering, pustular

Question 3

Types of exanthematous reactions

Answer 3

Maculopapular rash and DRESS (drug reaction with eosinophilia and systemic symptoms)

Question 4

Types of urticarial reactions

Answer 4

Urticaria/angioedema and serum sickness-like syndrome

Question 5

Types of blistering reactions

Answer 5

Fixed drug eruption and SJS, TEN, SJS/TEN

Question 6

When does a maculopapular rash start?

Answer 6

7-10 days after drug initiation

Question 7

When does a maculopapular rash resolve?

Answer 7

Within 7-14 days of D/C

Question 8

Drug causes of a maculopapular rash

Answer 8

Penicillins, cephalosporins, sulfonamides, anticonvulsants

Question 9

Treatment of a maculopapular rash

Answer 9

Kids: can continue taking med as long as the rash isn’t itchy and doesn’t have a fever

Adults: switch to a non-penicillin

Question 10

DRESS symptoms

Answer 10

Exanthematous eruption, plus fever, lymphadenopathy around the site of the rash, hematologic abnormalities (eosinophilia), MULTIORGAN INVOLVEMENT (lungs, liver, kidneys)

Question 11

When does DRESS occur? (onset of action)

Answer 11

Starts 1-6 weeks after starting drug, average onset is 2-3 weeks

Question 12

Drug causes of DRESS

Answer 12

ALLOPURINOL
Sulfonamides
Anticonvulsants (phenobarbital, phenytoin, carbamazepine, lamotrigine)
Dapsone

Question 13

How long does it take to recover from DRESS?

Answer 13

6-8 weeks, can be relapse/remission in some cases

Question 14

DRESS treatment

Answer 14

Withdraw offending drug
Avoid starting new meds (avoid beta-lactams)
Fluid and electrolyte management, nutrition

Question 15

What anticonvulsant can you switch a patient to if they have DRESS and the culprit is another anticonvulsant (lamotrigine, carbamazepine, phenobarbital, phenytoin, etc.)

Answer 15

Valproic acid

Question 16

If there IS organ involvement, what med can you give for treatment of DRESS

Answer 16

Systemic corticosteroids: 0.5-2mg/kg/day of prednisone equivalents, tapered down over 8-12 weeks

Question 17

If there is NO organ involvement, what meds can you give for DRESS

Answer 17

High potency topical steroids BID-TID x1 week

Question 18

Super high potency steroids

Answer 18

Clobetasol 0.05%*
Flucinonide 0.1%
Betamethasone dipropionate augmented 0.05%
Halobetasol 0.05%

Question 19

High potency steroids

Answer 19

Flucinonide 0.05%
Halcinoninde 0.1%
Betamethasone diproprionate 0.05%
Triamcinolone 0.5%
Desoximetasone 0.05%

Question 20

Risk factors for DRESS caused by allopurinol

Answer 20

Excessive dose, renal dysfunction, concomitant thiazide diuretic, HTN, Asian ethnicity (HLA-B*58:01 allele)

Question 21

Urticaria is what type of hypersensitivity reaction?

Answer 21

Type I

Question 22

Symptoms of urticaria

Answer 22

Hives, pruritic red raised wheals, sometimes angioedema and swelling of mucous membranes

Question 23

Time of onset of urticaria

Answer 23

Minutes-hours

Question 24

Drug causes of urticaria

Answer 24

Penicillins and related ABX
Sulfonamides
ASA
Opiates
Latex

Question 25

Urticaria treatment

Answer 25

Stop offending drug and avoid it/drug class in the future

Question 26

Serum-sickness like reaction signs/symptoms

Answer 26

Urticaria, fever, arthralgias

Question 27

Onset of serum sickness-like reaction

Answer 27

1-3 weeks

Question 28

Drug causes of serum sickness-like reaction

Answer 28

Penicillins/cephalosporins | Sulfonamides

Question 29

Treatment of serum sickness-like reactions

Answer 29

Will go away on its own in 1-2 weeks

Question 30

Fixed drug eruption signs and symptoms

Answer 30

Eruptions with pruritic, erythematous, raised lesions that can blister Occur in the same place every time the drug is given

Question 31

Onset of fixed drug eruption

Answer 31

Within minutes-days

Question 32

Drug causes of fixed drug eruption

Answer 32

``` TTCs Barbituates Sulfonamides Codeine Phenolphthalein APAP NSAIDs ```

Question 33

Treatment of fixed drug eruption

Answer 33

Resolves within days of D/C

Question 34

Signs and symptoms of SJS, TEN, SJS/TEN

Answer 34

Painful bullous formation with systemic signs and symptoms like fever, headache, respiratory symptoms, body-wide mucous membrane involvement Lesions spread rapidly and cause epidermal, necrosis, detachment, and sloughing

Question 35

Onset of SJS, TEN, SJS/TEN

Answer 35

7-14 days

Question 36

Risk factors for SJS, TEN, SJS/TEN

Answer 36

HIV, lupus, malignancy/cancer, UV light/radiation therapy, HLA-B*15:02 gene in Asian patients

Question 37

Drug causes of SJS, TEN, SJS/TEN

Answer 37

``` Sulfonamides (Bactrim) Penicillins Anticonvulsants -oxicam NSAIDs Allopurinol ```

Question 38

SJS, TEN, SJS/TEN complications

Answer 38

Fluid loss, electrolyte imbalances, hypotension, secondary infections (caused by staph and MRSA) Treat with topical wound care and topical ABX

Question 39

SJS, TEN, SJS/TEN complications that require pharmacotherapy

Answer 39

Fluid loss, electrolyte imbalance, severe pain, hypovolemic shock and associated AKI, BACTEREMIA, hypercatabolic state, insulin resistance, pulmonary dysfunction requiring ventilation, GI dysfunction, multiple organ dysfunction syndrome

Question 40

SJS, TEN, SJS/TEN treatment

Answer 40

Withdraw offending drug and check for cross-reacting ones Pain management, fluid/electrolytes/nutrition Topical wound care: chlorhexidine, silver nitrate, silver sulfadiazine, gentamicin Ophthalmology consult: artificial tear drops or oinment, corticosteroids/antimicrobial combo for more severe cases

Question 41

Meds for SJS, TEN, SJS/TEN

Answer 41

Systemic corticosteroids: first line; may be effective in early treatment but increases immunosuppression and infection risk IVIG: first line; no increased infection risk but has a BBW of thromboembolism and AKI Cyclosporine: use if IVIG fails Thalidomide: NEVER`

Question 42

Sulfa ABX and sulfa non-ABX cross-reactivity

Answer 42

Cross-reactivity is minimal; if the patient has a mild sulfa ABX allergy they can still take the sulfa non-ABX. If severe, they should avoid sulfa drugs entirely

Question 43

PCNs and cephalosporins cross-reactivity

Answer 43

Cross-reactivity is minimal; look at the side chains of each and compare. The more similar it is, the more likely there is cross-reactivity

Question 44

Cross-reactivity between PCNs and cephalosporins is greater with what generations of cephalosporins?

Answer 44

First and second generations