Hi 
Welcome to Healthcare Magic Forum 
Looks like you have developed a lesion of Vector dermatitis, also known as 
Paederus dermatitis.. 
Paederus dermatitis 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. 
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 or oils till the time the lesion heals .
If the lesions continue to increase inspite of the above treatment, then you might have to see a 
dermatologist as in severe cases, short term courses of 
oral antibiotics or oral 
steroids may be required.
Hope it helps 
Wishing you speedy recovery 
Dr Geetika Paul