A Helvetic Embraer ERJ-190 on behalf of Swiss, registration HB-JVN performing flight LX-1585 from Vienna (Austria) to Zurich (Switzerland) with 45 passengers and 5 crew, was on approach to Zurich maintaining FL200 near Kempten (Germany) when the crew received indication of loss of cabin pressure and initiated a rapid descent. The aircraft lost de-icing systems at the same time prompting the crew to declare emergency. The aircraft continued for a safe landing on Zurich's runway 14 about 23 minutes after the loss of cabin pressure. Switzerland's SUST rated the occurrence a serious incident and opened an investigation