question: Hi, I have a reocurring allergy patch that comes up on the bottom of my back every now and then. It 1st came up about a year ago and has come up about 4 times since. It is extremely itchy and lumpy. It seems to weep slightly as it develops tiny scabs but I m not sure if this is due to the scratching . It always comes back in the same place and probably lasts about 2 to 4 weeks. It is around the same size as 2, 2penny coins (uk).