Contact Dermatitis


Allergic contact dermatitis results in red, hot, extremely itchy swollen skin sometimes with blistering and peeling. Typically contact dermatitis, as the term infers, is due to allergens directly contacting the skin. However diffuse involvement of the skin may stem from ingested allergens. The reaction is termed "delayed" as they develop between 12-48 hours after the exposure. The classic example for this reaction is the rash of poison ivy or poison oak.  

Determining what is causing the reaction is sometimes difficult.  Allergy patch testing maybe helpful in indentifying about 2/3 of triggers.  For the rest, some rules of thumb are helpful to decrease the amount of reactions. 

  1. Try to identify any new vitamins, supplements, medications that you started in the recent months
  2. Avoid all organic oils or “natural” products as these are very sensitizing and may make your skin worse
  3. Avoid any scents or dyes in products used on skin
  4. Avoid dryer sheets
  5. Use only physical sun screens containing zinc oxide or titanium oxide as the major ingredient
  6. Keep skin well moisturized
  7. Avoid scratchy or rough materials on the skin such as wool
  8. Suspect products that you have used for many years without issue

For diagnosis and treatment seek out the care of a board certified allergist. 


Photo by Vilseskogen on / CC BY-NC-SA

Sandra A. Ho, MD

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