Supplementary Material for: Pseudoephedrine-Associated Erythromelalgia: A Case Report of a Rare Drug Reaction

Introduction: Erythromelalgia is a rare disorder characterized by severe burning extremity pain, erythema and increased skin temperature. Symptoms are aggravated by warming and alleviated by cooling. It is known to be associated with multiple underlying conditions, as well as reactions in response to medications.
Case Presentation: A 38-year-old man experienced two distinct episodes of redness and swelling of his hands after taking “cold” tablets containing paracetamol and pseudoephedrine. His symptoms would peak 72 hours after onset despite discontinuing the medication. Upon being made aware that there was an association between pseudoephedrine and erythromelalgia, he avoided all pseudoephedrine-containing medications with no recurrence.
Conclusion: This case represents the second documented report of pseudoephedrine-associated erythromelalgia in the literature, with a proposed direct link due to the sympathetic adrenergic effects of pseudoephedrine on the vasculature.