45 - Cutaneous Reactions to Drugs Flashcards
Exanthematous eruptions account for approximately _____% of skin reactions
95
Exanthematous eruptions typically starts on the
Trunk
Y/N: Pruritus is almost always absent in exanthematous eruptions.
No - present
Examples of drug-virus interaction
Infectious mononucleosis - aminopenicillin
HIV - sulfonamide antibiotics
Exanthematous eruption in conjunction with fever and internal organ inflammation
Hypersensitivity syndrome reaction or
Drug-induced hypersensitivity syndrome or
Drug reaction with eosinophilia and systemic symptoms
HSR occurs most frequently on _____ exposure
First
Often the presenting symptoms of hypersensitivity syndrome reaction
Fever
Malaise
Possible long-term complication of HSR
Immune-mediated thyroid dysfunction
When deep dermal and subcutaneous tissues are also swollen, the reaction is known as
Angioedema
Frequently unilateral and nonpruritic and lasts for 1-2 hours
Angioedema
Drug-induced IgE-mediated immediate hypersensitivity causes
Penicillin
Other antibiotics
Drug-induced non-IgE-mediated immediate hypersensitivity causes
NSAIDs
ACE inhibitors
Defined by the presence of fever, rash (usually urticarial) and arthralgias
Serum sickness-like reactions
Associated with an increased relative risk of serum sickness-like reactions
Cefaclor
Previous hormonal priming is a necessary prerequisite in
Acneiform eruptions
Do not affect prepubertal children
Acneiform eruptions
There is contradictory evidence for the benefit of _____ for prophylaxis for acneiform eruptions
Tetracyclines
AGEP is an acute febrile pustular eruption that occurs _____ hours after initiation of the implicated drug
24-48
In AGEP, sterile pustules are concentrated on the
Trunk
Intertriginous areas
Usual treatment necessary in most patient with AGEP
Discontinuance of therapy
Pseudoporphyria is a cutaneous phototoxic disorder that can resemble either _____ in adults or _____ in children
Porphyria cutanea tarda
Erythropoietic protoporphyria
Pseudoporphyria differs from porphyria cutanea tarda and erythropoietic protoporphyria by the presence of
Normal porphyrin levels
Drug-induced vs idiopathic linear IgA disease
Mucosal or conjunctival lesions are less common
Spontaneous remission occurs once offending agents is removed
Immune deposits disappear once the lesions resolve
Most frequently reported cause of drug-induced linear IgA disease
Vancomycin
Drug-induced vs idiopathic bullous pemphigoid
Younger patients May have positive Nikolsky sign Lesions on normal-appearing skin Target lesions on palns and soles Involvement of the lower legs Mucosal involvement
FDE in women more commonly presenting with lesions on the ______, and men on the ______
Hands and feet
Genitalia
FDE may exhibit _____, a sign of incipient blister formation
Epidermal wrinkling
Most frequent culprits for FDE
NSAIDs
Acetaminophen
Antibioticso
Drug-induced vs idiopathic lichen planus
Often appear initially as eczematous with a purple hue
Involve large areas of the trunk
Mucous membranes and nails are not involved
Systemic symptons associated with drug-induced pseudolymphoma
Fever
Marked lymphadenopathy
Hepatosplenomegaly
Eosinophilia
Y/N: Most patients with drug-induced lupus have no cutaneous findings of lupus erythematosus.
Yes
Most common serologic abnormality in drug-induced lupus
Positivity for ANA with a homogeneous pattern
Unlike in idiopathic lupus erythematosus, _____ are typically absent, whereas _____ are often present
anti-dsDNA
anti-ssDNA
Causes of drug-induced lupus
Hydralazine Procainamide Isoniazid Methyldopa Minocycline
Most common drugs associated with SCLE
Terbinafine
Thiazide diuretics
Calcium channel blockers
Ranitidine
Drug-induced dermatomysitis causes
Hydroxyurea
Penicillamine
HMG-CoA reductase inhibitors
Drug-induced vasculitis represents approximately _____% of the acute cutaneous vasculitides
10
Drug-induced vs other causes of vasculitis
Less progression to glomerulonephritis
Better outcomes
Require less immunosuppressive treatment
Anticoagulant-induced skin necrosis develop in
Adipose-rich sites such as breasts, buttocks, and hips
Incidence of anticoagulant-induced skin necrosis is higher in
Women, majority of whom are obese
Treatment for neutrophilic eccrine hidradenitis
Colchicine
Prophylactic treatment for neutrophilic eccrine hidradenitis
Dapsone
New drugs started with the preceding 3 months are potential causative agents except in
Drug-induced lupus
Drug-induced pemphigus
Drug-induced cutaneous pseudolymphoma
IgE-mediated; immediate-type immunologic reactions
Type 1
Drug + cytotoxic antibodies cause lysis of cells such as platelets or leukocytes
Type II
IgG or IgM antibodies formed to drug; immune complexes deposited in small vessels active complement and recruit granulocytes
Type III
Cell-mediated immune reaction; sensitized lymphocytes react with drug, liberating cytokines, which trigger cutaneous inflammatory response
Type IV
Type of reaction: Urticaria/angioedema
Type I
Type of reaction: Petechiae resulting from thrombocytopenic purpura
Type II
Type of reaction: Drug-induced pemphigus
Type II
Type of reaction: Vasculitis
Type III
Type of reaction: Urticaria
Type III
Type of reaction: Serum sickness
Type III
Type of reaction: Morbilliform exanthematous reactions
Type IV
Type of reaction: Fixed drug eruption
Type IV
Type of reaction: Lichenoid eruptions
Type IV
Type of reaction: SJS-TEN
Type IV
Patch testing has greater sensitivity if performed
Over a previously involved area of skin
SCORTEN criteria is calculated within
First 24 hours of admission
SCORTEN criteria
Age older than 40 years Urea < 10 mmol/L Glucose > 14 mmol/L Bicarbonate < 20 mEq/L Heart rate > 120 bpm Presence of malignancy BSA > 10% at presentation
SCORTEN mortality ranging from _____% (1 point) to _____% (5 points)
3.2
90
Index of suspicion of drug induction in linear IgA disease should be higher in cases with
Only IgA and no IgG in the basement membrane zone
