Since levocetirizine (Teczine) and hydroxyzine (Atarax) are not providing relief, the underlying cause might not be purely histamine-related. It is very reassuring that your blood tests are normal, as this helps rule out many serious systemic conditions. Sometimes, rashes can be triggered by contact allergies, viral infections, or localized skin reactions that require targeted treatments like topical anti-inflammatories rather than oral antihistamines. I highly recommend visiting a dermatologist for a physical examination to identify the exact cause and get you the right relief.