A large red blister, two days, the feeling of hot, hot, hot.
According to the picture, the current thighs and chest reddening of this sign, and there are small blisters, the first suspected it is a manifestation of allergic eczema, normal with the application of ointment can be, no effect with oral medication
The local rash with blisters with pain is considered to be viral caused by herpes, it is recommended to go to the pharmacy to buy anti-viral creams to apply, like acyclovir cream 3 to 4 times a day, it is best to cooperate with oral anti-viral oral solution, avoid spicy and irritating food.
According to the picture you took, it may be caused by skin allergy. It is recommended that you can use Furfuryl lotion for cleaning, and at the same time you can apply some glucocorticoid ointment for relief.Normally, you must pay attention to the cleanliness of the skin and avoid scratching, so as not to cause skin breakage leading to infection.