welcome to healthcare magic forum
thank you for your query
black itchy spot in scalp
may be due to lice
infection or fungal infection
it look like more of fungal infection.
you need to consult dermatologist
as treatment of both condition are different.
keep your scalp skin clean and do not let it wet.
avoid scratching and use separate comb.
for itching you can take anti histaminic medicine .
i hope i answered your question