 [ Symptoms ] what cause lumps on a baby is leg the lump is are not ichiy and the skin is not red but he extends his leg is when you move your hand over the lump is on his leg is what could be causeing this [ Disease ] your description is really not sufficient for me to even make a wild guess i do not know your baby is age or the location of these lumps and obviously i have no way of feelingexamining 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