Hi welcome to Health care magic forum.
Thanks for choosing H.C.M.F.
The straight line marks on the body of your son , If they are red must got them in them in the night, probably by scratching by his own nails,if black or brown they can be previous days happenings, still no matter how did they occur.
Now what you have to do is consult a doctor and let him have a tetanus toxoid injection
, to prevent tetanus infection. He should be given antibiotics to completely cure the scratchs. if you have a pet dog and is aquainted with the boy, he should be given anti rabies
Wishing for a qiick recovery.