allergic contact dermatitis

Last reviewed 10/2020

Allergic contact dermatitis accounts for 20% of cases of all contact dermatitis

  • this requires prior sensitization of the skin to a specific allergen. T lymphocytes become specially sensitised to the allergen and upon fresh contact with it, mediate a dermatitis reaction typically within 48hours
  • it is an example of a type IV hypersensitivity reaction (1)
  • affects 1-2% of the population

It occurs twice as frequently in women as in men, and often starts at a young age (2).

The number of children with allergic contact dermatitis is increasing. It has been suggested that children with eczematous eruptions should be patch-tested, especially children with hand and eyelid eczema (3).

Prognosis for allergic contact dermatitis is usually worse compared to irritant contact dermatitis unless the allergen is identified and avoided (1).

A common cause of this type of dermatitis is nickel.