| | • | vs.pemphigus vegetans (distribution = intertriginous) | 
| • | pathogenesis – appears to be an allergic phenomenon | 
| • | once sensitized, eruption can occur within a few days of re-administration | 
| • | good response to corticosteroids | 
  Iododerma: | • | begins as a rule with multiple pustules that rapidly coalesce into vegetating plaques (often ulcerate) | 
| • | frequently associated with severe systemic symptoms | 
| • | iodine containing compounds:  IV pyelogram, urography, lymphography | 
  Fluoroderma: | • | described after the frequent application of a fluoride gel to the teeth for the purpose of preventing caries during ionizing radiation to the face | 
| • | scattered papules and nodules on the neck and on the preauricular region | 
  Bromoderma: | • | distribution = lower extremities | 
| • | vegetating, papillomatous plaques with pustules at the periphery | 
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