Case Study: Pruritic Rash Diagnosis

Jonathan Sim, a 32-year-old management consultant, presents with a 3 month history of an unremitting pruritic rash on his arms and legs. He denies changing soaps or laundry detergent. He has tried over-the-­counter topical hydrocortisone without improvement. On further history, he reports that 2 months ago he returned from Singapore, where he had been living for the past several months for work. He found living in Singapore quite stressful as he was away from his wife and young son, who were living in Penang while he was overseas. Jonathan has no significant past medical history. His travel immunisations are all up-to­date. He considers himself quite active and has been training for his first half marathon, however this has been curtailed due to recent right knee pain. He has been using Ibuprofen 400 mg PO TDS for the last few weeks to help. Jonathan smokes 5 cigarettes a day, and drinks 2 standard drinks on an average weekend. On examination, his vital signs are within normal limits. Examination of the rash on the right arm is as shown below (see image).