I've had (what I think) is a cyst on my back for years. Every so often DH will squeeze it and clear it out, then it's fine for ages. About a month ago he got loads of out it, far more than usual. He was very pleased with himself! Yesterday evening it suddenly started feeling bruised and hard, and now feels itchy. Would have to happen right before Christmas so I can't just book an appointment with the GP. What do I do with it?