Just discovered this in my son’s hair. What is it? Not sure if we should go to doc

Other signs:
Pet is scratching excessively
Discover more
spice
Slow Cooker
Salsa
Egg
Science
Eggs
Spice
Slow cooker
Bites on child’s ankles or legs
 What to do:
Treat pets and home for fleas.
Discover more
Science
spice
Slow cooker
Eggs
Slow Cooker
Spice
Egg
Salsa
Wash child’s hair with regular shampoo.
See a doctor only if bites become infected or cause severe allergic reaction.
 4. Hair Product Residue or Hard Water Buildup
What it looks like:
White flakes or crust that rinses out with clarifying shampoo.
Discover more
Salsa
Slow Cooker
Slow cooker
Spice
Egg
Eggs
spice
Science
Often near hairline or where products are applied.
Other signs:
Hair feels stiff or dull
Discover more
spice
Spice
Egg
Eggs
Slow cooker
Salsa
Slow Cooker
Science
No itching or redness
 What to do:
Use a clarifying shampoo or apple cider vinegar rinse.
No medical concern.
 When to Call the Doctor Right Away
Discover more
Salsa
Slow Cooker
Egg
Science
spice
Slow cooker
Eggs
Spice
Seek medical attention if you notice:

Black or brown specks that move (could be mites or other parasites)
Discover more
Science