The itching of red stripes at the waistband of pants can be divided into physiological and pathological. Physiologic may be related to excessive tightness at the waistband. Pathologic may be related to contact dermatitis. If the physiological factors are excluded, it is recommended that the patient go to the hospital in time. 1. Physiological: the waistband of pants is too tight, squeezing the skin. This leads to transient strangulation and itching of the skin, which can usually be relieved on its own without special treatment. 2. Contact dermatitis: skin contact with certain exogenous substances, causing inflammatory reactions in the contact area or even the skin outside the contact area. It can be manifested as erythema, edema, papules and other skin lesions, and may appear to feel itching, burning, swelling and pain and other symptoms. If physiological factors are excluded, patients are advised to go to the hospital in time.