You are seeing a 30-year-old female in primary care who has presented with a rash. On questioning, the patient informs you that the rash has been present for several days and it is getting worse. On examination you note the presence of well-delineated red, scaly plaques on the outside of the elbows and knees. The patient also informs you that this rash is itchy and burns throughout the day. What is the most likely diagnosis?