00:00
In this lecture, we're going to discuss DRESS Syndrome or Drug Reaction with Eosinophilia and
Systemic Symptoms. This is a severe allergic reaction that we're seeing more and more in the
United States. So here's a classic example. "A 10-year-old boy comes in to the ER with a fever
and a widespread pruritic rash. His face is swollen and erythrodermic. He began taking
carbamazepine for his newly diagnosed epilepsy around 5 weeks ago." What's on your
differential diagnosis? Well, certainly you might be thinking about things like Stevens-Johnson
syndrome or just a bad allergic reaction like angioedema but we have to think about DRESS
syndrome in this case and there are a few clues and one of them is the drug he is on. So let's
get down into DRESS syndrome. DRESS syndrome is a drug reaction with eosinophilia and
systemic symptoms so we see eosinophilia and we see a variety of symptoms. It's a severe
drug-induced hypersensitivity reaction with a mortality of 8 to 10%. Children die of this
problem so we have to be aware it's happening. The pathophysiology of this disease is unknown.
01:20
We don't really understand why it's happening, it's a complex immune reaction. Patients
present with a number of clinical symptoms. They almost always will have fever. They will
almost always have rash. They will often have lymphadenopathy. You will notice generally
hematologic abnormalities and the one you want to look for is eosinophilia. They may also have
an atypical lymphocytosis. What's key here though is they can have organ involvement anywhere
from liver failure to renal failure to cardiopulmonary failure or even thyroid involvement and we
can get labs that show alterations of these various organ systems. So, here's an example of
the characteristic rash in these patients. It's a bright red, body-wide erythroderma. It's very
obvious. It's widespread and it's variable where it shows up the most. Generally, it's on the
core and then moves out to the extremities. There is a delayed onset between when the patient
is exposed to the antigen that causes DRESS and when they developed their symptoms, generally
2 to 8 weeks later. So it's not like their first dose of the new med, it's usually a substantial
number of weeks later. It's commonly morabiliform and you see that erythroderma. You may see
erythematous macules, it will be pruritic or itchy and you may see a variety of other things like
papules, pustules, vesicles, bullae, purpura. You shouldn't be stirred away from it as a diagnosis
because you see an unusual element to that rash but what's key is the erythroderma and they
may also get facial edema. So, when we draw blood on these patients if we are suspecting this
might be DRESS syndrome, we will see eosinophilia on a CBC. Often, they'll have atypical
lymphocytosis with large activated lymphocytes or lymphoblasts and you may notice increased
serum liver function tests as well as increased BUN and creatinine and other findings consistent
with organic failure. Let's look at those organs. Generally with the liver, there's a simple transaminitis
although fulminant hepatic necrosis is reported. Patients will often have a mild hematuria,
maybe even a microscopic hematuria although it can go all the way up through frank renal failure.
04:00
Patients may develop a pneumonitis, an inflammation of the lungs that can also drive up your
right-sided pressures. They may develop a pericarditis or an inflammation of the sac around the heart or
a frank involvement of the muscles of the heart leading to cardiac failure and patients may get
a thyroiditis as a result of the inflammation of the thyroid gland. So, what's key then is understanding
what are the drugs that are most likely to cause this problem. Well, most commonly we see it
with the onset of the administration of aromatic antiepileptic drugs. Examples are phenytoin,
carbamazepine, or phenobarbital. It's also seen fairly frequently with the tetracyclines:
tetracycline, minocycline or doxycycline. Remember those drugs are not benign and have quite
a few side effects. There are other medications too that can cause this problem. So examples
would be NSAIDs which is a rare but known complication of NSAIDs as well as beta-blockers,
ACE inhibitors, a variety of medications can do it even allopurinol although we really don't use that
in children very often. So how do we treat DRESS? Treatment is largely supportive but the first
step is obviously removing the offending agent and then waiting for resolution of symptoms.
05:28
This can be challenging in patients with severe seizure disorders as we now have to go find another
agent that will control their seizures while we wait for this reaction to resolve. We often will
give these patients systemic glucocorticoids. We give them some steroids that can help resolve
some of the symptoms and we provide supportive care, blood pressure support, dialysis if it's
severe renal disease, etc. So that's a brief summary of DRESS Syndrome in Children. Thanks for
your attention.