Welcome to healthcare magic
Tackle the itching and the bruising also will clear.
You should rule out a condition called meralgia paraesthetica
which can occur over the above site without any visible rash, just itching due to compression of cutaneous nerves especially in over weight individuals.
Also rule out common cause of rash like fungal infection
I will recommend you to consult a dermatologist
Get antihistamine prescribed by your primary care
physician till you get appointment.
Hope this helped