The phenomenon of small bumps on the arms without pain or itching is very common, and there are many reasons that can cause small bumps on the arms without pain or itching, mainly the following: 1, follicular keratosis, follicular keratosis and genetic related, is caused by keratinization of the mouth of the hair follicles. The skin surface touch has a granular feeling, not smooth, like goose bumps, you can use salicylic acid for exfoliation for care. 2, chronic eczema, generally after the acute period itching pain will be relieved, but the limbs, especially the arms will appear papules.