The phenomenon of a small red rash at the base of the thigh may be due to eczema, ringworm, prickly heat and other factors, and can be relieved through general treatment, medication and other ways. 1. Eczema: some patients may be exposed to irritants or allergens, resulting in localized eczema phenomenon, manifested as a small red rash at the base of the thighs, can be treated with topical hydrocortisone, dexamethasone and other ointments coated. If necessary, you can take oral antihistamines such as loratadine. 2. ringworm: this is mainly due to dermatophyte infection of the skin, will be accompanied by symptoms of flaking and itching, can be treated with topical ketoconazole, econazole, clotrimazole and other antifungal drugs to improve the patient’s symptoms. If necessary, oral itraconazole and other drugs can be combined. 3. prickly heat: in the hot summer, the patient may be due to the thigh root area is not breathable, so the phenomenon of prickly heat, as a red rash, accompanied by itching phenomenon, through oral loratadine, cetirizine and other drugs, to improve the local itching symptoms. At the same time, external use of glycerine lotion, prickly heat powder and other drugs. In addition, you need to pay attention to the local skin dry and clean. A small red rash on the thigh root may also have other causes, it is recommended to consult a doctor to determine the cause before treatment. The above medications should be used in accordance with medical advice.