Itchy knees and bumps are usually caused by allergic dermatitis of the skin in the knee area due to external stimuli, resulting in localized rashes and itching. In this case, you can apply compound dexamethasone cream to the itchy spots, which has anti-allergic effect and can effectively reduce the local rash and itching symptoms. You can also apply the Miao medicine skin poisonous Kang cream, can also play a good therapeutic effect. You can also take oral prednisone acetate tablets and dexamethasone tablets, which can effectively play an anti-allergic role in reducing the inflammation caused by local allergies, can play a good therapeutic effect. However, care should be taken to avoid re-exposure of the knee area to external physical stimuli in the knee area, such as foreign objects and external stimuli around the knee area. And pay attention to eat light, avoid eating spicy, stimulating and fat, sweet, thick and greasy food, as well as seafood, can effectively prevent further aggravation of allergies.