How to Differentiate Between the Contact Irritant Dermatitis and Allergic Contact Dermatitis?
Differentiating between the two types of contact dermatitis is important from the preventive and management point of view. • Contact irritant dermatitis is dose dependent: higher the amount of irritant, stronger the reaction. Allergic contact dermatitis is not dose dependent; once the individual is sensitized, even minute quantities can produce allergic reaction on the skin. • As contact irritant dermatitis is a toxic reaction, it involves only the area of contact with the irritant. The margins are sharply defined; the reaction does not extend beyond. In allergic contact dermatitis, the reaction can occur outside area of contact, even in remote areas of the body which never came in contact with the allergen. Thus generalized allergic reaction is possibly in ACD. • Anyone can get contact irritant dermatitis, but only sensitized individuals get allergic contact dermatitis. Contact dermatitis, both irritant and allergic, is the major cause for occupational skin disease in many industrial
