Drug eruptions Flashcards
What is an adverse drug reaction (ADR)?
An adverse drug reaction (ADR) is a response to a drug that is noxious and unintended, occurring at doses normally used in humans for the prophylaxis, diagnosis, therapy of disease, or for the modification of physiological function (WHO definition).
What is another name for Morbilliform Drug Eruption?
Morbilliform Drug Eruption is also known as Exanthematous or Maculopapular Drug Eruption.
What is the typical onset time for Morbilliform Drug Eruption after initiating a drug?
The onset typically occurs 7–14 days after drug initiation.
What are the common clinical features of Morbilliform Drug Eruption?
Common features include red-pink macules and papules that start in the groin/axilla and are symmetrically distributed on the trunk and upper extremities. The rash is usually itchy and may be accompanied by a low-grade fever.
Does Morbilliform Drug Eruption involve mucous membranes?
No, Morbilliform Drug Eruption typically spares mucous membranes.
How is Morbilliform Drug Eruption managed?
Management involves identifying and stopping the causative drug. The rash usually clears within 1–2 weeks after stopping the drug, and treatment may include topical steroids and anti-itch medications.
Which class of antibiotics is commonly associated with Morbilliform Drug Eruption?
Penicillins and sulfonamides are commonly associated with Morbilliform Drug Eruption.
What type of medication, often used for epilepsy, is linked to Morbilliform Drug Eruption?
Anticonvulsants are often linked to Morbilliform Drug Eruption
Which medication used for gout is associated with Morbilliform Drug Eruption?
Allopurinol, a medication used for gout, is associated with Morbilliform Drug Eruption
Are nonsteroidal anti-inflammatory drugs (NSAIDs) associated with Morbilliform Drug Eruption?
Yes, NSAIDs are also commonly associated with Morbilliform Drug Eruption.
What is a Fixed Drug Eruption (FDE)?
A Fixed Drug Eruption is a type of drug reaction characterized by the development of one or more round, sharply demarcated erythematous and edematous plaques that recur at the same site(s) upon re-exposure to the offending drug.
When do lesions typically develop after the first exposure to a drug in Fixed Drug Eruption?
Lesions typically develop 1 to 2 weeks after the first exposure to the drug.
How quickly do lesions reappear in Fixed Drug Eruption after subsequent exposures to the offending drug?
Lesions can reappear within 24 hours after subsequent exposures to the offending drug.
What is the clinical presentation of Fixed Drug Eruption lesions?
Lesions are round, sharply demarcated, erythematous, and edematous plaques, sometimes with a dusky, violaceous hue, central blister, or detached epidermis. They can be found anywhere on the body, favoring areas like the lips, face, hands, feet, and genitalia.
What is the typical progression and resolution of Fixed Drug Eruption lesions?
Lesions progressively fade over several days, leaving post-inflammatory brown pigmentation
What happens when the causative drug is re-administered in a patient with Fixed Drug Eruption?
The lesions recur at exactly the same sites when the drug is re-administered.
What is referred to as generalized Fixed Drug Eruption?
The presence of numerous lesions in Fixed Drug Eruption is referred to as generalized Fixed Drug Eruption.
Which drugs are most commonly associated with Fixed Drug Eruption?
Drugs most commonly associated with Fixed Drug Eruption include sulfonamides, NSAIDs, barbiturates, tetracyclines, and carbamazepine
What are Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)?
SJS and TEN are potentially fatal adverse cutaneous drug reactions characterized by mucocutaneous tenderness, erythema, and extensive exfoliation, with SJS affecting less than 10% of body surface area (BSA) and TEN affecting more than 30% of BSA.
What is the difference between SJS, SJS-TEN overlap, and TEN?
SJS affects less than 10% of BSA, SJS-TEN overlap affects 10-30% of BSA, and TEN affects more than 30% of BSA.
What are the common prodromal symptoms of SJS and TEN?
Common prodromal symptoms include fever, malaise, myalgias, arthralgias, and conjunctival itching or burning, typically occurring 1-3 weeks after the initiation of the offending drug
Describe the cutaneous lesions characteristic of SJS and TEN.
Cutaneous lesions start as erythematous to violaceous and purpuric macules that coalesce into patches, progress to vesicles or flaccid bullae, and eventually lead to dusky plaques with sloughing (necrosis and epidermal detachment). Nikolsky’s sign may be positive.
What is the immediate management strategy for SJS/TEN?
Immediate management includes the withdrawal of the causative drug and admission to a hospital, ideally in an ICU or burn unit setting, for supportive treatment including fluid replacement, nutritional support, and infection management
What are the key components of supportive treatment for SJS/TEN?
Supportive treatment includes fluid replacement, nutritional support, administration of corticosteroids (dexamethasone), intravenous immunoglobulins (IVIg), topical antiseptics for dressings, and monitoring and treating infections such as Staphylococcus aureus or Pseudomonas.
