My 10 year old son has striped bruising on both sides of face coming from temples. what are the causes as i doctor cannot seem to find a cause.

Let's think: If a full evaluation has been done without revealing any pathology, there must be a logical explanation. Does he lay on his side with headphones on? Does he lay on the floor in front of the tv with his hands on his head? Does he wear a helmet that fits too tight in those areas? It could be something simple -- good luck.

See below: Difficult to suggest possibilities without seeing the condition. Has he had recent dental work? Any history of trauma (e.g. From wrestling)? Baseball helmet too tight? See pediatrician for evaluation & options for treatment. Good history may provide the answer.

Due to trauma: Since your son sounds overall healthy and without other conditions, i think the bruising is due to very mild friction/trauma. This happens because his skin has become thin & the tissues that support the underlying blood vessels are more fragile. Mild friction or rubbing may induce this. If this were a trend for something more serious-he might have bleeding gums/frequent nosebleeds.