These erythema grow on my body these days, itch a bit, what skin disease is this

The appearance of long erythema and itching is usually considered to be the cause of urticaria, which may be caused by genetic factors, insect bites, hot and cold stimulation, sun exposure, hormone abuse, etc. Antihistamines such as loratadine are generally required for treatment, and immunosuppressants may be added for severe cases.