History: These images show the multiple brown red macules and papules that developed on this young lady's back over a period of several years.She occasionally had itch when she showered and rubbing the skin would cause the lesions to urticate because of histamine release from the excessive number of mast cells. The histology shows excessive numbers of mast cells around the blood vessels in the upper dermis.The Toluidine blue stain shows the mast cells more clearly. Treatment of this condition is very difficult but is summarised in the DermnetNZ reference.