Clinical Features:

• Caused by direct damage to the skin by physical or chemical substances
• Clinically indistinguishable from allergic contact dermatitis, the distinction being made on the basis of history and skin allergen testing
• Unlike in allergic contact dermatits, no prior sensitization is required.
• Common inciting agents include those encountered through occupational exposure, such as detergents and motor oil
• Acute irritant dermatitis presents with scaling, erythema, vesicles or erosions. 
• Chronic irritant dermatitis presents with dryness and chapping without vesicles.

Histologic Features:

• The histologic features are basically identical to those of allergic contact dermatitis:
  • Spongiosis with intraepidermal vesicle formation
  • Dermal edema
  • Irregular psoriasiform hyperplasia (in subacute and chronic lesions)
  • Upper dermal perivascular lymphocytic infiltrate
• Features that may be more prominent in irritant than in allergic contact dermatitis are:
  • Epidermal necrosis
  • Neutophils
  • Acantholysis
• Features that may be present in allergic contact dermatitis but that are usually absent from irritant contact dermatitis are:
  • Eosinophils
  • Langerhans cell clusters
  • Extensive exocytosis of lymphocytes

Cases associated with this book:

Irritant contact dermatitis
Author: Artur Zembowicz M.D. Ph.D.

Conference: DermatopathologyConsultations.com Teaching Collection