skin reaction types in contact dermatitis

Last reviewed 03/2021

skin reaction types in contact dermatitis

Contact dermatitis may be classified into the following reaction types:

  • subjective irritancy
    • idiosyncratic stinging and smarting reactions occur within minutes of contact, usually on the face, in the absence of visible changes
    • cosmetic or sunscreen constituents are common precipitants

  • acute irritant contact dermatitis
    • often caused by
      • a single overwhelming exposure or
      • a few brief exposures to strong irritants or caustic agents

  • chronic (cumulative) irritant contact dermatitis
    • results from repetitive exposure to weaker irritants. These irritants may be either
      • wet - detergents, organic solvents, soaps, weak acids and alkalis
      • dry - low-humidity air, heat, powders, paper, cardboard and dusts

  • allergic contact dermatitis
    • this involves sensitization of the immune system to a specific allergen or allergens with resulting dermatitis or exacerbation of pre-existing dermatitis

  • phototoxic, photoallergic and photoaggravated contact dermatitis
    • some allergens are also photoallergens

  • systemic contact dermatitis (systemic allergic dermatitis)
    • occurs following systemic administration of a chemical, usually a drug, to which topical sensitization has occurred previously

  • protein contact dermatitis
    • repetitive handling of proteins, usually foods, results initially in immediate urticarial symptoms and signs, but later progresses to a dermatitic reaction
    • proteins may be
      • vegetables - potato, garlic
      • meats, fish - in food handlers
      • flour, enzymes - in bakers and pharmaceutical manufacture
      • animal dander and fluids - in veterinarians and abattoir workers

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