1. Center for Blistering Diseases, Department of Dermatology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700 RB Groningen, the Netherlands
2. Department of Dermatology, Philipps University of Marburg, Marburg, Germany
3. Departments of Otorhinolaryngology
4. Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands