External irritants can sometimes cause a previously retractable prepuce to become non-retractable due to swelling of the tissues. If a child whose prepuce was retractable becomes non-retractable, environmental factors should be investigated. One known culprit is bubble bath. If a child is taking bubble baths and the prepuce becomes non-retractable, the bubble bath should be discontinued. See Penile Hygiene in the Intact Non-circumcised Male for comprehensive information on foreskin care.
I'm excited about the potential for outlier and anomaly detection. Picking the right method, one which complements the data can be a challenge. But as we see more and more real-world examples hopefully, the various use cases and applications of these algorithms will become more obvious. But beyond the algorithms, I hope that the potential applications of anomaly detection will see a shift in the way we talk about our data: what is normal, are we collecting the right data for this and what is interesting? One day very soon hopefully, all of our alerting thresholds will be data-driven, with a clear narrative for the customer about "what normal is for them", and a reduction in the number of charts on our dashboards by focusing on abnormalities - the things that are really interesting.