Hello. Welcome to ask the doctor.
I have seen the attached photograph also.
As per details, the most likely possibility for your symptoms is pedrous dermatitis. It is also known as insect bite reaction.
It is always noticed suddenly and spontaneously usually in the morning .
In such cases, I prefer to advise a combination of antibiotic and steroid like hydrocortisone cream over the affected area. Take some antihistaminics like levocetirizine for symptomatic relief.
Visit your doctor so that he can examine you and give you prescription.
You can share my opinion with him.
I hope it helps.
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