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NEW ORLEANS – Most skin eruptions in patients taking antiepileptic drugs (AEDs) are relatively benign. With close supervision, some patients with epilepsy may continue treatment despite having a benign drug rash, according to a lecture at the annual meeting of the American Epilepsy Society.
“When do you know that you’re not dealing with that kind of eruption?” said Jeanne M. Young, MD, assistant professor of dermatology at the University of Virginia in Charlottesville.
Signs and symptoms that raise concerns about severe cutaneous reactions include swelling of the face; lesions that are fluid-filled, dusky, or painful; mucus membrane involvement; and signs of systemic involvement.
Associations with anticonvulsants
Diffuse swelling of the face is a hallmark symptom of DRESS. Fluid-filled lesions such as pustules, vesicles, and bullae indicate a condition other than a benign drug eruption. Signs of systemic involvement may include fever, marked eosinophilia, transaminitis, and evidence of lymphocyte activation. “In general, I want to see systemic involvement that can’t be explained by the patient’s other systemic diseases,” Dr. Young said.
A 2018 study found that AEDs are associated with SJS and TEN, and the labels for lamotrigine and carbamazepine include black box warnings about the risk of severe cutaneous adverse events. Carbamazepine’s warning, which was added in 2007, notes that SJS and TEN are significantly more common in patients of Asian ancestry with the human leukocyte antigen allele HLA-B*1502 and that physicians should screen at-risk patients before starting treatment.
Benign drug rashes
Morbilliform drug eruptions, sometimes called benign exanthems, are “by far the most common drug rash that we see” and typically are “the rashes that people refer to as drug rashes,” Dr. Young said. The mechanisms appear to be primarily immune complex mediated and cell mediated. “When the drug is stopped, these rashes tend to go away quite predictably in 2-3 weeks.”
For any class of drug, about 1% of people taking that medication may have this type of reaction, Dr. Young said. “We expect to see erythematous papules and plaques that oftentimes become confluent on the skin.” These reactions generally occur 7-10 days after the first exposure to the medication, and most patients do not have other symptoms, although the rash may itch. In addition, patients may have erythroderma with desquamation. “I think it’s important to point out the difference between desquamation, which is loss of the stratum corneum, and epidermal sloughing, which is what you see in something like [SJS] or TEN, where you’re actually losing the entire epidermis,” Dr. Young said. Recovering from desquamation is “sort of like recovering from a sun burn, and it’s not particularly dangerous.” Management of morbilliform drug eruptions is largely symptomatic.
Treat through, taper, or rechallenge
In the case a benign drug rash, “if you feel like you … need to keep a patient on a drug, you do have that option with close supervision,” Dr. Young said. “Communicate that with the dermatologist. Say, ‘I have really struggled getting this patient stabilized. Can we keep them on this drug?’ ”
The dermatologist may not fully realize the implications of stopping an effective AED in a patient with seizures that have been difficult to control. If the drug rash is benign, treating through may be an option. Patients often resolve the rash while continuing the medication, which may be because of desensitization, Dr. Young said. If a patient’s symptoms are too great to continue the drug, neurologists have the option of slowly tapering the drug and reinitiating with a new drug, Dr. Young said. Neurologists also may choose to rechallenge.
If a patient is on several medications, making it difficult to elucidate a causative agent, after stopping those drugs and allowing the rash to resolve, “there is little danger in restarting a medication,” she said.
Benign rash or DRESS?
“When I see a morbilliform eruption, usually what’s on my mind is, ‘Is this just a drug rash or is this DRESS?’ ” Dr. Young said. DRESS often starts with a morbilliform eruption that is indistinguishable from a benign drug eruption.
“Timing is a major difference,” she said. “If a patient develops a morbilliform drug eruption much later than I would expect, then my suspicion [for DRESS] goes up.” Patients with DRESS often have fever and systemic symptoms. Proposed DRESS diagnostic criteria can be useful, but clinical judgment still plays a key role. If a patient does not satisfy diagnostic criteria but has some signs and is taking a drug that is associated with DRESS, “it is going to make me more suspicious and maybe make me recommend stopping that drug sooner,” she said. Anticonvulsants such as carbamazepine, lamotrigine, and phenobarbital are among the drugs most commonly associated with DRESS.
Toxic erythemas
Patients may present with toxic erythemas, such as fixed drug reactions, erythema multiforme, SJS, and TEN. These drug reactions appear similar on biopsy but have different courses.
A patient with a fixed drug reaction often has a single lesion, and the lesion will occur in the same location every time the patient is exposed to the drug. Patients may develop additional lesions with subsequent exposures. These lesions typically are large, erythematous, well-demarcated plaques with central duskiness. “They can be bullous in the center, and they typically will heal with pigmentation, which is unique to this particular drug reaction,” said Dr. Young. “When it gets more concerning and most important to differentiate is when you get generalized bullous fixed drug eruption.” Generalized bullous fixed drug eruptions mimic and are difficult to clinically distinguish from TEN, which has a much has a much poorer prognosis.
Patients with a fixed drug eruption are not as ill as patients with TEN and tend not to slough their skin to the extent seen with TEN. Interferon gamma, perforin, and Fas ligand have been implicated as mechanisms involved in fixed drug reactions. Unlike in TEN, regulatory T cells are abundant, which may explain why TEN and fixed drug reactions progress differently even though they appear to share pathologic mechanisms, Dr. Young said.
Erythema multiforme generally presents with classic target lesions and little mucosal involvement. Infections, most commonly herpes simplex virus (HSV) 1 and 2, may trigger erythema multiforme. Dr. Young recommends evaluating patients for HSV and checking serologies, even if patients have never had a herpes outbreak. “If you have no evidence for infection, you do have to consider discontinuing a medication,” she said.
Stevens–Johnson syndrome and TEN
SJS and TEN are “the rarest of the severe cutaneous adverse drug reactions” and have “the highest morbidity and mortality,” Dr. Young said. They appear to exist on a continuum where SJS may represent early TEN.
“This is a situation where you expect to see blistering of the skin [and] always mucosal involvement. You need to stop the drug immediately when you suspect this drug reaction,” Dr. Young said.
One reason to distinguish SJS or early TEN from later TEN is that high-dose steroids may play a role in the treatment of SJS or early TEN. “Once you get past about 10% total body surface area, there is good evidence that steroids actually increase morbidity and mortality,” she said.
If the eruption has occurred before, that factor suggests that a diagnosis of erythema multiforme or fixed drug reaction may be more likely than TEN.
An apparent lack of regulatory T cells in TEN could explain why patients with HIV infection are at much higher risk of developing SJS and TEN. Understanding the role that regulatory T cells play in severe drug eruptions may lead to new therapeutic options in the future, Dr. Young said.
Dr. Young had no disclosures.
NEW ORLEANS – Most skin eruptions in patients taking antiepileptic drugs (AEDs) are relatively benign. With close supervision, some patients with epilepsy may continue treatment despite having a benign drug rash, according to a lecture at the annual meeting of the American Epilepsy Society.
“When do you know that you’re not dealing with that kind of eruption?” said Jeanne M. Young, MD, assistant professor of dermatology at the University of Virginia in Charlottesville.
Signs and symptoms that raise concerns about severe cutaneous reactions include swelling of the face; lesions that are fluid-filled, dusky, or painful; mucus membrane involvement; and signs of systemic involvement.
Associations with anticonvulsants
Diffuse swelling of the face is a hallmark symptom of DRESS. Fluid-filled lesions such as pustules, vesicles, and bullae indicate a condition other than a benign drug eruption. Signs of systemic involvement may include fever, marked eosinophilia, transaminitis, and evidence of lymphocyte activation. “In general, I want to see systemic involvement that can’t be explained by the patient’s other systemic diseases,” Dr. Young said.
A 2018 study found that AEDs are associated with SJS and TEN, and the labels for lamotrigine and carbamazepine include black box warnings about the risk of severe cutaneous adverse events. Carbamazepine’s warning, which was added in 2007, notes that SJS and TEN are significantly more common in patients of Asian ancestry with the human leukocyte antigen allele HLA-B*1502 and that physicians should screen at-risk patients before starting treatment.
Benign drug rashes
Morbilliform drug eruptions, sometimes called benign exanthems, are “by far the most common drug rash that we see” and typically are “the rashes that people refer to as drug rashes,” Dr. Young said. The mechanisms appear to be primarily immune complex mediated and cell mediated. “When the drug is stopped, these rashes tend to go away quite predictably in 2-3 weeks.”
For any class of drug, about 1% of people taking that medication may have this type of reaction, Dr. Young said. “We expect to see erythematous papules and plaques that oftentimes become confluent on the skin.” These reactions generally occur 7-10 days after the first exposure to the medication, and most patients do not have other symptoms, although the rash may itch. In addition, patients may have erythroderma with desquamation. “I think it’s important to point out the difference between desquamation, which is loss of the stratum corneum, and epidermal sloughing, which is what you see in something like [SJS] or TEN, where you’re actually losing the entire epidermis,” Dr. Young said. Recovering from desquamation is “sort of like recovering from a sun burn, and it’s not particularly dangerous.” Management of morbilliform drug eruptions is largely symptomatic.
Treat through, taper, or rechallenge
In the case a benign drug rash, “if you feel like you … need to keep a patient on a drug, you do have that option with close supervision,” Dr. Young said. “Communicate that with the dermatologist. Say, ‘I have really struggled getting this patient stabilized. Can we keep them on this drug?’ ”
The dermatologist may not fully realize the implications of stopping an effective AED in a patient with seizures that have been difficult to control. If the drug rash is benign, treating through may be an option. Patients often resolve the rash while continuing the medication, which may be because of desensitization, Dr. Young said. If a patient’s symptoms are too great to continue the drug, neurologists have the option of slowly tapering the drug and reinitiating with a new drug, Dr. Young said. Neurologists also may choose to rechallenge.
If a patient is on several medications, making it difficult to elucidate a causative agent, after stopping those drugs and allowing the rash to resolve, “there is little danger in restarting a medication,” she said.
Benign rash or DRESS?
“When I see a morbilliform eruption, usually what’s on my mind is, ‘Is this just a drug rash or is this DRESS?’ ” Dr. Young said. DRESS often starts with a morbilliform eruption that is indistinguishable from a benign drug eruption.
“Timing is a major difference,” she said. “If a patient develops a morbilliform drug eruption much later than I would expect, then my suspicion [for DRESS] goes up.” Patients with DRESS often have fever and systemic symptoms. Proposed DRESS diagnostic criteria can be useful, but clinical judgment still plays a key role. If a patient does not satisfy diagnostic criteria but has some signs and is taking a drug that is associated with DRESS, “it is going to make me more suspicious and maybe make me recommend stopping that drug sooner,” she said. Anticonvulsants such as carbamazepine, lamotrigine, and phenobarbital are among the drugs most commonly associated with DRESS.
Toxic erythemas
Patients may present with toxic erythemas, such as fixed drug reactions, erythema multiforme, SJS, and TEN. These drug reactions appear similar on biopsy but have different courses.
A patient with a fixed drug reaction often has a single lesion, and the lesion will occur in the same location every time the patient is exposed to the drug. Patients may develop additional lesions with subsequent exposures. These lesions typically are large, erythematous, well-demarcated plaques with central duskiness. “They can be bullous in the center, and they typically will heal with pigmentation, which is unique to this particular drug reaction,” said Dr. Young. “When it gets more concerning and most important to differentiate is when you get generalized bullous fixed drug eruption.” Generalized bullous fixed drug eruptions mimic and are difficult to clinically distinguish from TEN, which has a much has a much poorer prognosis.
Patients with a fixed drug eruption are not as ill as patients with TEN and tend not to slough their skin to the extent seen with TEN. Interferon gamma, perforin, and Fas ligand have been implicated as mechanisms involved in fixed drug reactions. Unlike in TEN, regulatory T cells are abundant, which may explain why TEN and fixed drug reactions progress differently even though they appear to share pathologic mechanisms, Dr. Young said.
Erythema multiforme generally presents with classic target lesions and little mucosal involvement. Infections, most commonly herpes simplex virus (HSV) 1 and 2, may trigger erythema multiforme. Dr. Young recommends evaluating patients for HSV and checking serologies, even if patients have never had a herpes outbreak. “If you have no evidence for infection, you do have to consider discontinuing a medication,” she said.
Stevens–Johnson syndrome and TEN
SJS and TEN are “the rarest of the severe cutaneous adverse drug reactions” and have “the highest morbidity and mortality,” Dr. Young said. They appear to exist on a continuum where SJS may represent early TEN.
“This is a situation where you expect to see blistering of the skin [and] always mucosal involvement. You need to stop the drug immediately when you suspect this drug reaction,” Dr. Young said.
One reason to distinguish SJS or early TEN from later TEN is that high-dose steroids may play a role in the treatment of SJS or early TEN. “Once you get past about 10% total body surface area, there is good evidence that steroids actually increase morbidity and mortality,” she said.
If the eruption has occurred before, that factor suggests that a diagnosis of erythema multiforme or fixed drug reaction may be more likely than TEN.
An apparent lack of regulatory T cells in TEN could explain why patients with HIV infection are at much higher risk of developing SJS and TEN. Understanding the role that regulatory T cells play in severe drug eruptions may lead to new therapeutic options in the future, Dr. Young said.
Dr. Young had no disclosures.
NEW ORLEANS – Most skin eruptions in patients taking antiepileptic drugs (AEDs) are relatively benign. With close supervision, some patients with epilepsy may continue treatment despite having a benign drug rash, according to a lecture at the annual meeting of the American Epilepsy Society.
“When do you know that you’re not dealing with that kind of eruption?” said Jeanne M. Young, MD, assistant professor of dermatology at the University of Virginia in Charlottesville.
Signs and symptoms that raise concerns about severe cutaneous reactions include swelling of the face; lesions that are fluid-filled, dusky, or painful; mucus membrane involvement; and signs of systemic involvement.
Associations with anticonvulsants
Diffuse swelling of the face is a hallmark symptom of DRESS. Fluid-filled lesions such as pustules, vesicles, and bullae indicate a condition other than a benign drug eruption. Signs of systemic involvement may include fever, marked eosinophilia, transaminitis, and evidence of lymphocyte activation. “In general, I want to see systemic involvement that can’t be explained by the patient’s other systemic diseases,” Dr. Young said.
A 2018 study found that AEDs are associated with SJS and TEN, and the labels for lamotrigine and carbamazepine include black box warnings about the risk of severe cutaneous adverse events. Carbamazepine’s warning, which was added in 2007, notes that SJS and TEN are significantly more common in patients of Asian ancestry with the human leukocyte antigen allele HLA-B*1502 and that physicians should screen at-risk patients before starting treatment.
Benign drug rashes
Morbilliform drug eruptions, sometimes called benign exanthems, are “by far the most common drug rash that we see” and typically are “the rashes that people refer to as drug rashes,” Dr. Young said. The mechanisms appear to be primarily immune complex mediated and cell mediated. “When the drug is stopped, these rashes tend to go away quite predictably in 2-3 weeks.”
For any class of drug, about 1% of people taking that medication may have this type of reaction, Dr. Young said. “We expect to see erythematous papules and plaques that oftentimes become confluent on the skin.” These reactions generally occur 7-10 days after the first exposure to the medication, and most patients do not have other symptoms, although the rash may itch. In addition, patients may have erythroderma with desquamation. “I think it’s important to point out the difference between desquamation, which is loss of the stratum corneum, and epidermal sloughing, which is what you see in something like [SJS] or TEN, where you’re actually losing the entire epidermis,” Dr. Young said. Recovering from desquamation is “sort of like recovering from a sun burn, and it’s not particularly dangerous.” Management of morbilliform drug eruptions is largely symptomatic.
Treat through, taper, or rechallenge
In the case a benign drug rash, “if you feel like you … need to keep a patient on a drug, you do have that option with close supervision,” Dr. Young said. “Communicate that with the dermatologist. Say, ‘I have really struggled getting this patient stabilized. Can we keep them on this drug?’ ”
The dermatologist may not fully realize the implications of stopping an effective AED in a patient with seizures that have been difficult to control. If the drug rash is benign, treating through may be an option. Patients often resolve the rash while continuing the medication, which may be because of desensitization, Dr. Young said. If a patient’s symptoms are too great to continue the drug, neurologists have the option of slowly tapering the drug and reinitiating with a new drug, Dr. Young said. Neurologists also may choose to rechallenge.
If a patient is on several medications, making it difficult to elucidate a causative agent, after stopping those drugs and allowing the rash to resolve, “there is little danger in restarting a medication,” she said.
Benign rash or DRESS?
“When I see a morbilliform eruption, usually what’s on my mind is, ‘Is this just a drug rash or is this DRESS?’ ” Dr. Young said. DRESS often starts with a morbilliform eruption that is indistinguishable from a benign drug eruption.
“Timing is a major difference,” she said. “If a patient develops a morbilliform drug eruption much later than I would expect, then my suspicion [for DRESS] goes up.” Patients with DRESS often have fever and systemic symptoms. Proposed DRESS diagnostic criteria can be useful, but clinical judgment still plays a key role. If a patient does not satisfy diagnostic criteria but has some signs and is taking a drug that is associated with DRESS, “it is going to make me more suspicious and maybe make me recommend stopping that drug sooner,” she said. Anticonvulsants such as carbamazepine, lamotrigine, and phenobarbital are among the drugs most commonly associated with DRESS.
Toxic erythemas
Patients may present with toxic erythemas, such as fixed drug reactions, erythema multiforme, SJS, and TEN. These drug reactions appear similar on biopsy but have different courses.
A patient with a fixed drug reaction often has a single lesion, and the lesion will occur in the same location every time the patient is exposed to the drug. Patients may develop additional lesions with subsequent exposures. These lesions typically are large, erythematous, well-demarcated plaques with central duskiness. “They can be bullous in the center, and they typically will heal with pigmentation, which is unique to this particular drug reaction,” said Dr. Young. “When it gets more concerning and most important to differentiate is when you get generalized bullous fixed drug eruption.” Generalized bullous fixed drug eruptions mimic and are difficult to clinically distinguish from TEN, which has a much has a much poorer prognosis.
Patients with a fixed drug eruption are not as ill as patients with TEN and tend not to slough their skin to the extent seen with TEN. Interferon gamma, perforin, and Fas ligand have been implicated as mechanisms involved in fixed drug reactions. Unlike in TEN, regulatory T cells are abundant, which may explain why TEN and fixed drug reactions progress differently even though they appear to share pathologic mechanisms, Dr. Young said.
Erythema multiforme generally presents with classic target lesions and little mucosal involvement. Infections, most commonly herpes simplex virus (HSV) 1 and 2, may trigger erythema multiforme. Dr. Young recommends evaluating patients for HSV and checking serologies, even if patients have never had a herpes outbreak. “If you have no evidence for infection, you do have to consider discontinuing a medication,” she said.
Stevens–Johnson syndrome and TEN
SJS and TEN are “the rarest of the severe cutaneous adverse drug reactions” and have “the highest morbidity and mortality,” Dr. Young said. They appear to exist on a continuum where SJS may represent early TEN.
“This is a situation where you expect to see blistering of the skin [and] always mucosal involvement. You need to stop the drug immediately when you suspect this drug reaction,” Dr. Young said.
One reason to distinguish SJS or early TEN from later TEN is that high-dose steroids may play a role in the treatment of SJS or early TEN. “Once you get past about 10% total body surface area, there is good evidence that steroids actually increase morbidity and mortality,” she said.
If the eruption has occurred before, that factor suggests that a diagnosis of erythema multiforme or fixed drug reaction may be more likely than TEN.
An apparent lack of regulatory T cells in TEN could explain why patients with HIV infection are at much higher risk of developing SJS and TEN. Understanding the role that regulatory T cells play in severe drug eruptions may lead to new therapeutic options in the future, Dr. Young said.
Dr. Young had no disclosures.
EXPERT ANALYSIS FROM AES 2018