Sores

Patient: Hi, i have a 5 yr old daughter who has been complaining of an itchy foott since last night. I told her to put lotion after her bath. But this morning she came crying to me that her foot was really itchy. There were 4-5 hard sores under the foot of irregular shapes. They are all under thick skin and look like they have fluid in them. She went swimming and to the park on that day that she started complaining. I took her to the doc and he said that it might be an allergic reaction to an insect bite or something. He prescribed a cream “Advantan”. The cream is not helping at all and the sores are getting bigger. I don’t really know what are the cause of these sores and what i should do to soothe the itchiness

Doctor: