That's not so easy, especially for clinical case studies. If any data points are irrelevant, they should not be stated at all, because they actually might not be irrelevant after all and by arbitrarily changing them, you could confound results. On the other hand, it has been shown that three or more indirect data points can already be enough to unmask you in an anonymized report. And most reports usually contain many more than that. So it's not surprising that journals would cover their backs by requiring consent, even if the law does not explicitly demand it.