The redness of the scrotum may be abraded by walking, and may also be related to dermatitis, eczema, epididymitis, orchitis and other diseases. 1. Traumatic abrasion: underwear is too tight, or the material is uncomfortable, resulting in abrasion when walking, then it may lead to scrotal injury, and then the phenomenon of red scrotum. 2. Dermatitis: Clinical symptoms are varied, and some patients may experience localized scrotal redness, swelling, itching and other discomfort. 3. Eczema: its main symptom can be manifested as localized pimples, accompanied by redness, swelling, itching and other uncomfortable symptoms. 4. Epididymitis: it can lead to redness and swelling of the scrotum, accompanied by pain, swelling and other symptoms. 5. Orchitis: especially acute orchitis, which can lead to redness, swelling and pain in the testicles, and some patients may be accompanied by other symptoms such as chills, high fever and nausea. The persistent redness of the scrotum may also be related to other causes, it is recommended to seek medical examination as soon as possible, to be targeted treatment, do not be negligent, so as not to delay the condition.