Sean Klepper M.D.
Artur Zembowicz M.D....
- 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.
- 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
- Features that may be present in allergic contact dermatitis but that are usually absent from irritant contact dermatitis are:
- Langerhans cell clusters
- Extensive exocytosis of lymphocytes