Hi there...it would have been better if you had put up a photo of the lesion. It lesion is pus filled, then a plain antibiotic cream like mupirocin or fusidic acid cream is sufficient. If it is just red pimple, then it could be to a insect bite reaction. In that case a mild steroid like flutivate might be required. Sometimes even milaria can occur in this hit weather. In such a case just calamine lotion will be sufficient. it is important to diagnose the lesion as treatment for each varies. So kindly consult a dermatologist for further evaluation.