Drug eruptions

Question 1

What is an adverse drug reaction (ADR)?

Answer 1

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).

Question 2

What is another name for Morbilliform Drug Eruption?

Answer 2

Morbilliform Drug Eruption is also known as Exanthematous or Maculopapular Drug Eruption.

Question 3

What is the typical onset time for Morbilliform Drug Eruption after initiating a drug?

Answer 3

The onset typically occurs 7–14 days after drug initiation.

Question 4

What are the common clinical features of Morbilliform Drug Eruption?

Answer 4

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.

Question 5

Does Morbilliform Drug Eruption involve mucous membranes?

Answer 5

No, Morbilliform Drug Eruption typically spares mucous membranes.

Question 6

How is Morbilliform Drug Eruption managed?

Answer 6

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.

Question 7

Which class of antibiotics is commonly associated with Morbilliform Drug Eruption?

Answer 7

Penicillins and sulfonamides are commonly associated with Morbilliform Drug Eruption.

Question 8

What type of medication, often used for epilepsy, is linked to Morbilliform Drug Eruption?

Answer 8

Anticonvulsants are often linked to Morbilliform Drug Eruption

Question 9

Which medication used for gout is associated with Morbilliform Drug Eruption?

Answer 9

Allopurinol, a medication used for gout, is associated with Morbilliform Drug Eruption

Question 10

Are nonsteroidal anti-inflammatory drugs (NSAIDs) associated with Morbilliform Drug Eruption?

Answer 10

Yes, NSAIDs are also commonly associated with Morbilliform Drug Eruption.

Question 11

What is a Fixed Drug Eruption (FDE)?

Answer 11

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.

Question 12

When do lesions typically develop after the first exposure to a drug in Fixed Drug Eruption?

Answer 12

Lesions typically develop 1 to 2 weeks after the first exposure to the drug.

Question 13

How quickly do lesions reappear in Fixed Drug Eruption after subsequent exposures to the offending drug?

Answer 13

Lesions can reappear within 24 hours after subsequent exposures to the offending drug.

Question 14

What is the clinical presentation of Fixed Drug Eruption lesions?

Answer 14

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.

Question 15

What is the typical progression and resolution of Fixed Drug Eruption lesions?

Answer 15

Lesions progressively fade over several days, leaving post-inflammatory brown pigmentation

Question 16

What happens when the causative drug is re-administered in a patient with Fixed Drug Eruption?

Answer 16

The lesions recur at exactly the same sites when the drug is re-administered.

Question 17

What is referred to as generalized Fixed Drug Eruption?

Answer 17

The presence of numerous lesions in Fixed Drug Eruption is referred to as generalized Fixed Drug Eruption.

Question 18

Which drugs are most commonly associated with Fixed Drug Eruption?

Answer 18

Drugs most commonly associated with Fixed Drug Eruption include sulfonamides, NSAIDs, barbiturates, tetracyclines, and carbamazepine

Question 19

What are Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)?

Answer 19

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.

Question 20

What is the difference between SJS, SJS-TEN overlap, and TEN?

Answer 20

SJS affects less than 10% of BSA, SJS-TEN overlap affects 10-30% of BSA, and TEN affects more than 30% of BSA.

Question 21

What are the common prodromal symptoms of SJS and TEN?

Answer 21

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

Question 22

Describe the cutaneous lesions characteristic of SJS and TEN.

Answer 22

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.

Question 23

What is the immediate management strategy for SJS/TEN?

Answer 23

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

Question 24

What are the key components of supportive treatment for SJS/TEN?

Answer 24

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.

Question 25

What is another name for Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)?

Answer 25

DRESS is also known as Drug-induced Hypersensitivity Syndrome (DIHS).

Question 26

What is the typical time frame for the onset of DRESS after drug initiation?

Answer 26

DRESS typically occurs 2 to 6 weeks after the initiation of the offending drug, which is later than other drug reactions.

Question 27

What are the hallmark clinical features of DRESS?

Answer 27

Hallmark features include a skin eruption, fever (85% of cases), lymphadenopathy, arthralgias, and multi-organ involvement, such as liver and kidney involvement. Peripheral eosinophilia (>1500 absolute eosinophils) is also a common feature.

Question 28

What is the characteristic triad of DRESS?

Answer 28

The characteristic triad of DRESS includes (1) skin eruptions, (2) hematologic abnormalities (such as hypereosinophilia and atypical lymphocytes/mononucleosis), and (3) one or multiple organ involvement.

Question 29

How does the skin eruption in DRESS typically present?

Answer 29

The rash typically starts on the face and upper trunk/extremities as a morbilliform eruption and becomes edematous, with facial edema being a classic early clue. Follicular accentuation, tense vesicles/bullae, pustules, and purpuric lesions may also be present.

Question 30

What is the management strategy for DRESS?

Answer 30

Early withdrawal of the offending drug is essential, but may not be sufficient for full recovery. In milder cases, high-potency topical corticosteroids may be helpful, while systemic corticosteroids are recommended for severe cases.

Question 31

What is Acute Generalized Exanthematous Pustulosis (AGEP)?

Answer 31

AGEP is an acute, febrile pustular drug eruption that often mimics pustular psoriasis and is characterized by the sudden appearance of sterile pustules on a background of edematous erythema.

Question 32

Which drugs are most commonly associated with AGEP?

Answer 32

The most common drugs associated with AGEP include β-lactam antibiotics (penicillins and cephalosporins), macrolide antibiotics, calcium channel blockers, and antimalarials.

Question 33

What is the typical clinical presentation of AGEP?

Answer 33

AGEP typically presents with a high fever occurring the same day as the rash onset, followed by numerous small, non-follicular, sterile pustules within large areas of edematous erythema. The eruption often begins on the face or intertriginous zones such as the axillae and groin. Additional findings in AGEP may include facial and hand edema, purpura, vesicles, bullae, erythema multiforme-like lesions, and mucous membrane involvement.

Question 34

What is the typical course of AGEP lesions?

Answer 34

AGEP lesions usually last 1-2 weeks, followed by superficial desquamation.

Question 35

How is AGEP managed?

Answer 35

Management of AGEP involves stopping the causative drug, providing supportive therapy, and using topical steroids and antipyretics to manage symptoms.