Rashes after bath. Be cured permanently.

Hello, My kid 7 year old has been showing mild rashes right after bath since 12 days. Rashes appear on back, sometimes on arms near elbows, legs, forehead. Some rashes are small (1inch) and some are about 2-3 inches . Some have a pimple kind of dot in center. They disappear within 10--20 mins of applying lotion. But they have been occuring everyday since last 12 days. Rashes are showing up only after bath and not any other time. Tried changing soap and lotion but didn't help. She had a severe utricarial rash in January '22. It was cured by citrizine. Not sure why it is occuring now again. *She had covid in the month of November '21 Can someone please guide what this is and what is causing it. How this can be cured permanently. Thanks, Sandhya