Von Allmen, who started for SC Bex, took part in competitions of the Fédération Internationale de Ski from 1997 to 2013 . He ran his first World Cup race in December 1999 in Engelberg , which he finished in 80th place in the sprint. In December 2001 he got his first World Cup points in Cogne with the 27th place. In the following year he achieved his first top ten place in the World Cup with ninth place in the sprint in Linz . At the Nordic World Ski Championships in 2003 in Val di Fiemme , he finished 16th in the sprint. Two years later he achieved 44th place in the sprint and 19th place together with Christoph Eigenmann in the team sprint at the Nordic World Ski Championships 2005 in Oberstdorf . In March 2009 he achieved his best result in the World Cup with fifth place in the sprint in Stockholm . At the 2010 Winter Olympics in Vancouver , he came in 43rd place in the sprint.
Von Allmen competed in 75 individual World Cup races and was in the points 24 times and in the top ten twice. In 2004 , 2006 and 2007 he was the Swiss sprint champion. In 2002 he took second place.