Thanks for your query
You seem to have developed a fixed drug eruption
It is a peculiar type of a drug reaction.
Round to oval bluish to purple spots or blisters can appear on body.
Try to recall all the drugs that you have taken prior to development of these lesions.
Take some oral antihistamines.
Apply some topical steroid
over the lesions.
take Care in future not to take the same offending drugs again as the reaction can be more severe next time.
Hope it helps
Dr Geetika Paul