Can a laser treatment for bruising 4 days after injection cause Radiesse to form hard lumps in the skin?

This is difficult to answer without pictures. It is unlikely that the laser caused lumps to form. Discoloration or hyperpigmentation can be improved with a combination of lasers, Aerolase, microneedling/prp, skin lightening, peels, and skin care. Sun protection is essential. Venus legacy and/or 5/FU steroids can help reverse Radiesse. I recommend getting a formal evaluation with a scarring expert. Best, Dr. Emer

I would not think that a laser treatment for bruising 4 days after a Radiesse injection would cause hard lumps to form in the skin.  It is difficult to say what might be causing that problem for you or the discoloration.  An examination of you and the details of your treatment would be needed to try and determine the cause.      

Really need photos to evaluate but if the lumps are inside and you only feel them with your tongue this is not unusual and will resolve. If the lumps are visible outside then steroid injection may help. Discoloration probably made worse by laser and can be treated with topical. Be sure you see a board certified dermatologist.