My whole body itches, and my limbs are covered with rashes and blisters. What disease is concentrated in the joints of limbs?

According to your description, eczema is not excluded, which is caused by allergies. It is a common epidermal inflammation with complicated etiology, which is generally considered to be closely related to allergic reaction.

It is recommended to take oral antiallergic drugs such as triprolidine hydrochloride capsules or loratadine tablets, vitamin C and calcium gluconate, and topical ointments such as paeonol ointment and Likang cream. After treatment, you will recover gradually, don't worry. Try to avoid external stimuli and local stimuli in daily life. Do not eat hot and sour dishes or other irritating foods. During the attack, avoid eating foods that are easy to cause allergies, such as yellow croaker, shrimp and seafood.