If i have a shower i have no problems. if i have a bath , after 10 min , my head itches very strong. why? is it a symptom of dermatitis seborroic?

?: I can't think of a mechanism for this since showering would involve your scalp but bathing likely not. There is a condition known as cholinergic urticaria in which intensely itchy red bumps would develop after a rise in core body temperature, but this does not fit your picture. It is also not suggestive of seborrhea. Suggest you see a dermatologist.