The red rash on the inner thighs may be caused by ringworm, eczema, allergic purpura, etc. It is recommended that the patient should first clarify the cause of the disease and do the corresponding treatment under the guidance of the doctor, such as fungal infections need antifungal medication, such as eczema need to use glucocorticosteroids, and such as allergic purpura need anti-allergic treatment. 1. ringworm: ringworm is caused by fungal infection in most cases, it is recommended that patients can use tretinoin econazole cream, ketoconazole cream, terbinafine hydrochloride cream and other drugs under the guidance of a doctor to alleviate the treatment and should pay attention to the process of recovery, change clothes, and keep the skin clean and hygienic. 2. eczema: patients due to infection caused by eczema, you can use zinc oxide ointment, Dinaid cream and other drugs under the guidance of the doctor for treatment, if there is a local oozing and other serious symptoms, you can use boric acid solution according to the condition of the local treatment. 3. Anaphylactic purpura: If the patient is caused by allergy, he can take anti-allergic drugs under the guidance of the doctor, such as cetirizine hydrochloride, chlorpheniramine maleate tablets, etc. If the itching is more serious, you can follow the doctor’s instructions for external use of haldolizine ointment and other medicines to relieve. It is recommended that patients should maintain local cleanliness and hygiene, and follow the doctor’s instructions to use medication, which can help the recovery of the condition.