your description is really not sufficient for me to even make a wild guess. i don't know your baby's age or the location of these lumps and obviously i have no way of feeling/examining them to give you a definitive answer. any chance that they are related to the vaccine administrations (on the upper thigh area). children often bleed a tiny bit under the skin from the injection. this area can form a tiny innocent lump that can take a while to self-resolve.
what cause lumps on a baby's leg. the lump's are not ichiy and the skin is not red but he extends his leg's when you move your hand over the lump's on his leg's what could be causeing this