The itchy redness on the inner side of the arms and thighs may be related to physiological factors such as dry skin, or eczema, hives and ringworm, etc., and can be improved by general treatment and medication. 1. Physiological factors: dry skin and other physiological factors may lead to a red itchy arms and thighs, it is recommended to drink plenty of water, keep the local clean, apply moisturizing lotion, avoid scratching the affected area, to help alleviate the symptoms. 2. Eczema: eczema may cause a red itchy inner arm and thigh, the patient should identify the causative agent, it is recommended that under the guidance of the doctor to apply Hasinide, Halometasone and other glucocorticoid ointment, with anti-inflammatory and anti-allergic effect. 3. Urticaria: arm and thigh a red itch may be caused by urticaria, it is recommended that patients follow the doctor’s instructions orally ibastine, cetirizine and other antihistamines, with anti-inflammatory and anti-itching effect. 4. ringworm: ringworm is a fungal infection, may also trigger the arms and thighs of a red itch, the patient should be diligent in changing clothes, need to be under the guidance of a doctor to use topical antifungal drugs, with antibacterial and bactericidal efficacy, such as miconazole, econazole, etc., to promote the recovery. There are many reasons for the red itchy inner arms and thighs, and after eliminating physiological factors, it is recommended that the patient consult a doctor for an examination, and under the guidance of the doctor, choose the appropriate treatment.