There are many ways to treat red bumps on thighs with allergies, mainly the following: first, to check the allergens and know what substances you are allergic to, so that you can make great efforts to avoid them in your future life and prevent the recurrence of allergies. Second, for the red bumps on the thigh allergy, you can use topical Furfuryl Glycolate lotion or Dermatoprene to apply, which can play a local role in relieving itching. Third, you can take oral anti-allergy drugs, mainly antihistamines, such as levocetirizine hydrochloride tablets, loratadine citrate tablets, epinastine hydrochloride capsules, etc. Oral anti-allergy drugs need to last for about a week before they can play a significant effect. Fourth, if the allergy itching is serious, do not scratch with your hands, once scratched and broken, it is easy to cause a large area of infection, you can use cool water wet compresses to reduce the itching.