I started with a small circular rash on the top
Eczematous rash or pityriasis rosea, topical steroid & antihistaminic
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I have gone through your complaints and reviewed the attached photographs.
It seems to be either an eczematous rash or pityriasis rosea which is an allergic reaction.
I would recommend you to apply topical steroid like cortisone cream on the affected areas twice daily and take antihistaminic like tablet cetrizine 10 mg once or twice daily depending on the intensity of itching and irritation.
I hope to have answered your query and would be happy to answer any further queries.