Drug Hypersensitivity Syndrome (DHS) and DRESS

00:02 The terminology around this syndrome has evolved a lot over the past 50 years since it was first described.

00:08 Ultimately, the terminology is as follows. It's called drug hypersensitivity syndrome with drug reaction with eosinophilia and systemic symptoms.

00:17 Interestingly, though, it used to be called drug rash with eosinophilia and systemic symptoms syndrome, and that's because the vast majority of patients did present with a rash.

00:26 It was an exfoliative dermatitis or potentially even erythroderma.

00:31 It is a delayed type hypersensitivity reaction that has multi-organ involvement, but it doesn't present nearly as fulminantly as something like SJS or TEN.

00:41 Typically, it's occurring 2-8 weeks into exposure to the medication, uch more delayed than the other drug reactions we've talked about.

00:48 And the most common agents we see are anticonvulsants, allopurinol, antibiotics, and NSAIDs. The most important hematologic abnormality is going to be the eosinophils you see on the right top, and then in the bottom, you're seeing what's called reactive lymphocytes.

01:04 So, it's these atypical lymphocytes, that you can see here with the grouped-up borders, that are characteristic feature of DHS/DRESS syndrome.

01:13 In addition, you may see transaminitis, you could see lymphadenopathy, which could look all the world like lymphoma. You may have kidney involvement, lung involvement, and ultimately, you're going to treat these patients with high doses of glucocorticoids. And of course, you're going to stop the offending agent. It can take months of treatment before this condition resolves.

01:35 Lastly, I'll just briefly mention the host of other ways that immune-mediated acute cutaneous drug reactions can manifest: drug-induced lupus, erythema nodosum, psoriasiform eruptions and pemphigus, all of which have been discussed in other lectures.