What is responsible for her itchy rash?
A 47-year-old female presented for evaluation of an itchy rash of 3 days duration that started 4 days after starting a sulfa antibiotic for a urinary tract infection. She also has been wearing an ankle brace on her left ankle after having an ankle fracture. Of interest, the rash is worse on the side where she has been wearing the ankle brace.
What is responsible for her rash?
c. Allergic reaction to ankle brace with ID reaction (autoeczematization)
d. Leukocytoclastic vasculitis secondary to the bacterial infection
e. Thrombocytopenia secondary to antibiotic or the infection
(Answer and discussion on next page)
Answer: Sulfa antibiotic drug reaction
This patient had a sulfa drug reaction that responded to a short prednisone taper. The absence of fever suggested there was no ongoing infection, especially in the absence of urinary symptoms. Pityriasis rosea should be on the trunk and not lower extremity. It was felt the swelling of the broken ankle and the increased skin blood flow due to the ankle brace contributed to increased reaction in the affected leg.