7 - 45 - CUTANEOUS REACTIONS TO DRUGS Flashcards
Populations that may have an increased risk of drug reactions in hospital
- HIV,
- connective tissue disorders (including lupus erythematosus),
- non-Hodgkin lymphoma,
- hepatitis
most common form of drug eruptions, accounting for approximately 95% of skin reactions
Exanthematous eruptions, sometimes referred to as morbilliform or maculopapular
- The eruption typically starts on the trunk and spreads peripherally in a symmetric fashion
- Pruritus is almost always present.
erythematous changes in the skin without blistering, pustulation, or associated systemic signs
Simple exanthems
Exanthematous eruptions usually occur within how many week/s of initiation of therapy?
and may appear how many days after drug therapy has been discontinued?
These eruptions usually occur within 1 week of initiation of therapy and may appear **1 or 2 days after drug therapy **has been discontinued
resolution of exanthematous eruptions occur within how many days?
Resolution, usually within 7 to 14 days, occurs with a change in color from bright red to a brownish red, which may be followed by desquamation
An **exanthematous eruption **in conjunction with fever and internal organ inflammation (eg, liver, kidney, CNS) signifies a more serious reaction, known as?
hypersensitivity syndrome reaction (HSR), drug-induced hypersensitivity reaction, or drug reaction with eosinophilia and systemic symptoms
- It occurs in approximately 1 in 3000 exposures to agents such as aromatic anticonvulsants, lamotrigine, sulfonamide antimicrobials, dapsone, nitrofurantoin, nevirapine, minocycline, metronidazole, and allopurinol
- Atypical lymphocytosis with subsequent eosinophilia may occur during the initial phases of the reaction in some patients.
- Although most patients have an exanthematous eruption, more serious cutaneous manifestations may be evident
often the presenting symptoms of Hypersensitivity syndrome reaction
Fever and malaise
Hypersensitivity syndrome reaction occurs most frequently on first exposure to the drug, with initial symptoms starting how many weeks after exposure?
1 to 6 weeks after exposure
possible long-term complication of hypersensitivity syndrome reaction
Immunemediated thyroid dysfunction resulting in hyperthyroidism or hypothyroidism
- may not present until **3 to 12 months **after the first symptoms appear
characterized by pruritic red wheals of various sizes
Urticaria
- Individual lesions generally last for less than 24 hours, although new lesions can commonly develop
When deep dermal and subcutaneous tissues are also swollen
he reaction is known as angioedema.
- Angioedema is frequently unilateral and nonpruritic and lasts for 1 to 2 hours, although it may persist for 2 to 5 days
Signs and symptoms of IgE-mediated allergic reactions
pruritus, urticaria, cutaneous flushing, angioedema, nausea, vomiting, diarrhea, abdominal pain, nasal congestion, rhinorrhea, laryngeal edema, and bronchospasm or hypotension
Drug-induced non–IgE-mediated urticaria and angioedema are usually related to what drugs?
nonsteroidal antiinflammatory drugs (NSAIDs) and angiotensinconverting enzyme (ACE) inhibitors
defined by the presence of** fever, rash** (usually urticarial), and arthralgias 1 to 3 weeks after initiation of drug therapy
Serum sickness–like reactions
- Lymphadenopathy and eosinophilia may also be present; however, in contrast to true serum sickness, immune complexes, hypocomplementemia, vasculitis, and renal lesions are absent.
drug associated with an increased relative risk of serum sickness–like reactions
Cefaclor
Other drugs that have been implicated in serum sickness–like reactions are cefprozil, bupropion, **minocycline, and rituximab **as well as infliximab
Acneiform eruptions are associated with the use of what drugs?
iodides, bromides, adrenocorticotropic hormone, glucocorticoids, isoniazid, androgens, lithium, actinomycin D, phenytoin, epidermal growth factor receptor inhibitors (eg, gefitinib, erlotinib, cetuximab)
- Drug-induced acne may appear in atypical areas, such as on the arms and legs, and is most often monomorphous.
acute febrile pustular eruption that occurs 24 to 48 hours after initiation of the implicated drug
AGEP
- It is characterized by small monomorphous nonfollicular sterile pustules concentrated on the trunk and intertriginous regions.
- Systemic features include leukocytosis with neutrophilia, fever, elevated liver enzymes with steatosis or hepatomegaly, renal insufficiency, and pleural effusions with hypoxemia
Generalized desquamation of AGEP occurs after approximately how many weeks?
2 weeks
most commonly associated drugs with AGEP
β-lactam, macrolide and quinolone, antibiotics, anticonvulsants, sulfonamides, calcium channel blockers (diltiazem), and terbinafine
cutaneous phototoxic disorder that can resemble either porphyria cutanea tarda in adults or erythropoietic protoporphyria in children but differs from these entities by the presence of normal porphyrin levels
Pseudoporphyria
- Pseudoporphyria of the porphyria cutanea tarda variety is characterized by skin fragility, blister formation, and scarring in photodistribution.
- The other clinical pattern mimics erythropoietic protoporphyria and manifests as cutaneous burning, erythema, vesiculation, angular chicken pox–like scars, and waxy thickening of the skin.
- The eruption may begin within 1 day of initiation of therapy or may be delayed in onset for as long as 1 year.
- The course is prolonged in some patients, but most reports describe symptoms that disappear several weeks to several months after the offending agent is withdrawn.
Drugs that have been associated with pseudoporphyria
naproxen and other NSAIDs, diuretics, antibiotics (tetracycline, ciprofloxacin, ampicillin-sulbactam/cefepime), retinoids, cyclosporine, dapsone, oral contraceptive pills, amiodarone, and voriconazole
areas of predilection of FDEs
genitalia and in the perianal area,
