The commonest reaction of the skin to penetration of the barrier layer by a substance on its surface is an inflammation referred to as eczema. The main signs of this condition are redness, swelling, blistering, flaking and cracking of the skin. The main symptom is itching. The type of eczema caused by contact with substances is called contact dermatitis.
It is important to make an accurate diagnosis of this condition as non-contact dermatitis and other skin conditions such as ringworm or psoriasis can result in similar signs and symptoms.