Thanks for your query
From the description of the skin lesion that you have developed, it looks like you have developed a lesion of insect bite or Vector dermatitis.
It is a peculiar, irritant contact dermatitis
characterized by a sudden onset of red lesions on exposed areas of the body.
The disease is provoked by an insect belonging to the genus Paederus.
Now you need to apply an antibiotic/steroid combination cream over the lesion twice a day.
Take oral antihistamine like levocetrizine once a day to decrease the swelling.
Do not use any moisturizer till the time the lesion heals .
Sometimes oral steroids
or antibiotics are needed if the lesion increases in size or persists.
Hope it helps
Wishing you speedy recovery
Dr Geetika Paul