I just noticed that I have a strange rash that spans across my lower back. It looks as though I have been wearing very tight corduroy pants. Lots and lots of vertical, red lines that are evenly spaced. They are raised and somewhat itchy. (I have been wearing loose fitting clothes all day).I wonder if it is an allergic reaction?
Hello, Could be an allergic reaction to elastic in undergarments or clothing. I suggest you to use a moderately potent topical steroid e.g. triamcinolone acetone cream, twice daily for a few days.  In addition, I suggest you take an oral antihistamine e.g. Cetirizine tablet once a day for a few days.  Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor. , Dermatologist