Itchy bumps on the joints may be caused by neurodermatitis, papular urticaria, eczema and other causes. 1. Neurodermatitis: the cause of neurodermatitis is still unclear, mainly associated with scratching and chronic friction, occurring in the neck, elbow joints, knee joints and other friction-prone parts of the skin surface for the appearance of reddish, normal skin color, tawny flat papules, that is, small bumps, the surface of the smooth or a little bit of a few scales, accompanied by intense itching symptoms. 2. Papular urticaria: small bumps appear when the joints are bitten by mosquitoes, accompanied by intense itching. 3. Eczema: easy to allergic patients, when the joints come into contact with allergens, such as animal fur, pollen, etc., may induce eczema, so that the surface of the skin appeared corn size pimples, pimples, accompanied by intense itching symptoms. Itchy bumps on the joints may also have other causes, it is recommended to go to the hospital in time to improve the examination, to clarify the cause of the disease to give targeted treatment.