The red itchy inner thighs, consider the following possibilities: 1, contact dermatitis, mainly due to contact with chemical fiber underwear or lining pants, and caused by an allergic reaction. The rash is clearly defined, with edematous erythema and accompanied by a certain itching. In this case, you can take oral loratadine capsules 1 time/day, 1 capsule/time, combined with compound glycyrrhizin capsules 3 times/day, 2 capsules/time, and apply wet rubs of compound Phellodendron japonica 2 times/day. After the color has darkened, then apply dextran ointment 1:1 mixed with zinc oxide borate ointment, 2 times/day topically. 2. Consider the possibility of ringworm, which is mainly caused by fungal infection and can appear as flaky erythematous patches with slightly elevated edges, with fine scales and some itching, which can be treated with topical compound ketoconazole ointment.