I would have to say that since it has been 3 weeks and you have been applying Hydrocortisone and it hasn't gone away, you should see a doctor. Using Hydrocortisone for too long can cause the skin to become very thin. The doctor will be able to prescribe a stronger derm cream if needed. If you are able to paste a picture or a link to a picture of this rash that would help me to confirm this also. If this answer is helpful please hit the accept button. Thank you.
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