Drug-Induced Dermatology Flashcards
What should you always ask a patient when they come into the pharmacy and they have a rash?
Do you have a fever?
Four categories of cutaneous drug eruptions
Exanthematous, urticarial, blistering, pustular
Types of exanthematous reactions
Maculopapular rash and DRESS (drug reaction with eosinophilia and systemic symptoms)
Types of urticarial reactions
Urticaria/angioedema and serum sickness-like syndrome
Types of blistering reactions
Fixed drug eruption and SJS, TEN, SJS/TEN
When does a maculopapular rash start?
7-10 days after drug initiation
When does a maculopapular rash resolve?
Within 7-14 days of D/C
Drug causes of a maculopapular rash
Penicillins, cephalosporins, sulfonamides, anticonvulsants
Treatment of a maculopapular rash
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
DRESS symptoms
Exanthematous eruption, plus fever, lymphadenopathy around the site of the rash, hematologic abnormalities (eosinophilia), MULTIORGAN INVOLVEMENT (lungs, liver, kidneys)
When does DRESS occur? (onset of action)
Starts 1-6 weeks after starting drug, average onset is 2-3 weeks
Drug causes of DRESS
ALLOPURINOL
Sulfonamides
Anticonvulsants (phenobarbital, phenytoin, carbamazepine, lamotrigine)
Dapsone
How long does it take to recover from DRESS?
6-8 weeks, can be relapse/remission in some cases
DRESS treatment
Withdraw offending drug
Avoid starting new meds (avoid beta-lactams)
Fluid and electrolyte management, nutrition
What anticonvulsant can you switch a patient to if they have DRESS and the culprit is another anticonvulsant (lamotrigine, carbamazepine, phenobarbital, phenytoin, etc.)
Valproic acid
If there IS organ involvement, what med can you give for treatment of DRESS
Systemic corticosteroids: 0.5-2mg/kg/day of prednisone equivalents, tapered down over 8-12 weeks
If there is NO organ involvement, what meds can you give for DRESS
High potency topical steroids BID-TID x1 week
Super high potency steroids
Clobetasol 0.05%*
Flucinonide 0.1%
Betamethasone dipropionate augmented 0.05%
Halobetasol 0.05%
High potency steroids
Flucinonide 0.05% Halcinoninde 0.1% Betamethasone diproprionate 0.05% Triamcinolone 0.5% Desoximetasone 0.05%
Risk factors for DRESS caused by allopurinol
Excessive dose, renal dysfunction, concomitant thiazide diuretic, HTN, Asian ethnicity (HLA-B*58:01 allele)
Urticaria is what type of hypersensitivity reaction?
Type I
Symptoms of urticaria
Hives, pruritic red raised wheals, sometimes angioedema and swelling of mucous membranes
Time of onset of urticaria
Minutes-hours
Drug causes of urticaria
Penicillins and related ABX Sulfonamides ASA Opiates Latex
Urticaria treatment
Stop offending drug and avoid it/drug class in the future
Serum-sickness like reaction signs/symptoms
Urticaria, fever, arthralgias
Onset of serum sickness-like reaction
1-3 weeks
Drug causes of serum sickness-like reaction
Penicillins/cephalosporins
Sulfonamides
Treatment of serum sickness-like reactions
Will go away on its own in 1-2 weeks
Fixed drug eruption signs and symptoms
Eruptions with pruritic, erythematous, raised lesions that can blister
Occur in the same place every time the drug is given
Onset of fixed drug eruption
Within minutes-days
Drug causes of fixed drug eruption
TTCs Barbituates Sulfonamides Codeine Phenolphthalein APAP NSAIDs
Treatment of fixed drug eruption
Resolves within days of D/C
Signs and symptoms of SJS, TEN, SJS/TEN
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
Onset of SJS, TEN, SJS/TEN
7-14 days
Risk factors for SJS, TEN, SJS/TEN
HIV, lupus, malignancy/cancer, UV light/radiation therapy, HLA-B*15:02 gene in Asian patients
Drug causes of SJS, TEN, SJS/TEN
Sulfonamides (Bactrim) Penicillins Anticonvulsants -oxicam NSAIDs Allopurinol
SJS, TEN, SJS/TEN complications
Fluid loss, electrolyte imbalances, hypotension, secondary infections (caused by staph and MRSA)
Treat with topical wound care and topical ABX
SJS, TEN, SJS/TEN complications that require pharmacotherapy
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
SJS, TEN, SJS/TEN treatment
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
Meds for SJS, TEN, SJS/TEN
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`
Sulfa ABX and sulfa non-ABX cross-reactivity
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
PCNs and cephalosporins cross-reactivity
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
Cross-reactivity between PCNs and cephalosporins is greater with what generations of cephalosporins?
First and second generations
