This is a symptom again of a bacterial infection. First of all Check your water, take a scrape from both the skin and the gills and observe these under a high power microscope and try and identify the parasite. As soon as you can treat for this parasite and if possible and if your ability stretches to it - obtain a good anti-biotic injection such as Baytril or Kefzol (but only use Kefzol if ithe fish is over 6 inches) If you are unable to do this job yourself then you should enlist the help of a professional such as your veterinary surgeon  You will lose the head-down fish within a week to ten days and then others will follow if you do not intercept the parasites which may have caused this condition.