My 3 year old son had surgery about 3 weeks ago and woke up from the surgery with a lump on the back of his head , took him to the ER and they just said it was a sore bump from him being asleep for 4 hours but now he has a bald spot where the lump was . What could that be?
After prolonged surgery or prolonged position of the head in a same position, leading to ischemia and reduced blood flow a point on the head skin due to constant pressure, this kind of thing can happen. It is called as a pressure sore and may lead even to permanent baldness in that region. Presently, just observation is required, and you can apply an oil based ointment on it. Will reduce in size. It may long time to heal fully.