Hi, You seem to have developed an allergic skin rash. Such a skin rash can occur due to many reasons. It can occur due to intake of some oral pain killers or antibiotics or due to some viral illness in body like after some sore throat or abdominal infection. You should avoid applying any kind of skin irritants like dettol, spirit over it. You might need to apply a topical steroid cream over the affected area twice a day for few days. Take some oral antihistamines along. See a nearby dermatologist if the condition tends to persist despite this therapy. You might need a course of oral steroids. Hope it helps, Dr Geetika Paul. MD(Dermatology)