DRESS Long-Term — SCE Dermatology MCQ

Correct answer: B — Autoimmune thyroiditis — developing in 5-10% of DRESS patients months after resolution

The correct answer is B, autoimmune thyroiditis, developing in 5 to 10% of DRESS patients months after resolution. DRESS (drug reaction with eosinophilia and systemic symptoms) triggers profound T cell activation and cytokine dysregulation, often with reactivation of human herpesvirus 6, and as this immune response resolves patients can lose self tolerance and develop autoimmune endocrinopathy, most commonly Hashimoto thyroiditis, occurring weeks to months (even up to two years) after the acute eruption has settled. This is why thyroid function testing is recommended at intervals during follow-up after DRESS rather than a single test at discharge. The stem's discriminating features, a carbamazepine-induced DRESS with facial oedema, eosinophilia and hepatitis, is the classic scenario in which this delayed autoimmune sequela is described and specifically tested for on recovery. Why the other options are wrong: E. Chronic liver disease always: Hepatitis is common in the acute phase of DRESS and is usually the cause of death when severe, but liver function typically normalises after recovery and chronic liver disease is not an inevitable ("always") long-term outcome. C. None: This ignores well documented autoimmune sequelae reported after DRESS resolution, so it understates the need for ongoing monitoring. D. Recurrent DRESS: Recurrence is not the expected long-term issue once the culprit drug and cross-reactive agents are permanently avoided; the concern after avoidance is autoimmune sequelae, not repeat episodes of DRESS itself. A. Chronic kidney disease always: Renal involvement can occur acutely in severe DRESS but, like option E, "always" is incorrect as an absolute long-term outcome and it is not the classically monitored sequela. Key point: After DRESS resolves, monitor thyroid function (and other autoimmune markers) for months to years, because delayed autoimmune thyroiditis is a recognised and specifically anticipated sequela of the immune dysregulation caused by the reaction.

Reference: Medsafe New Zealand (Prescriber Update, 2020), 'DRESS syndrome: monitor for long-term sequelae', citing Kano Y et al. 2015 survey of autoimmune sequelae after DRESS/DIHS; concordant with British Association of Dermatologists guidance on long-term follow-up after severe cutaneous adverse drug reactions. https://medsafe.govt.nz/profs/PUArticles/September2020/DRESS-syndrome-monitor-for-long-term-sequelae.html