Your symptoms of recurrent itching and rashes that improve temporarily with Ebast-20 suggest a likely allergic condition (such as urticaria/hives), and your raised IgE level (337) supports an underlying tendency toward allergy, which may be triggered by foods, dust, heat, stress, infections, or unknown factors. Since the relief is short-lived, this may be chronic or recurrent urticaria, which often requires longer-duration treatment rather than occasional tablets. You should try to identify and avoid triggers (common ones include seafood, eggs, packaged foods, dust, and tight clothing), keep your skin cool, avoid hot showers, use mild soaps, and apply moisturisers regularly. Instead of taking antihistamines only when symptoms appear, a doctor may advise a daily antihistamine for a few weeks, and in resistant cases, additional medicines may be needed after evaluation. Please avoid self-medicating frequently and consult a physician or dermatologist to rule out other causes and plan proper long-term control.