Cleanliness is not just wearing neat cloths it begins with your bedsheets and then the closest clothes to your skin.
Change your beddings every 3 - 7 days.
wash and aerate them in the sun every 7 days.
Iron your clothes always especially underpants (Boxers and vests.)
Always air your underpants, vests and socks in the sun to dry, not in the bathroom.
Scabies, Pinworms, Crab lice, Botfly & their eggs & maggots, hide in your beddings when moist is left in them exposing you to infections of different kinds.
Scabies are caused by a mite.
Pinworms causes anal itchiness.
Crab lice cause pediculosis pubis - symptoms include itchiness and discomfort in the scrotal and pubis area.
Bot fly cause myiasis.
All these are skin infestations and they can be very stubborn to go away.
The mysterious itchiness every morning or after a bath especially a cold bath could be a sign that you have some of the listed infestations above.
Clean up thoroughly especially underwear
Cheers