What is a common result of contact with irritants or allergens?

Contact with irritants or allergens commonly leads to the development of a red, itchy rash, which is a manifestation of the body’s inflammatory response. When the skin is exposed to substances that either irritate or provoke an allergic reaction, the immune system responds by increasing blood flow to the area and activating immune cells, such as mast cells. This process releases chemicals like histamines, resulting in symptoms such as redness, swelling, and itching. The rash that occurs can be a sign of conditions like contact dermatitis, where the skin reacts to the irritant or allergen.

The other options do not accurately describe the most typical immediate reaction to such contact. Increased collagen production is more associated with wound healing and not a direct response to irritants. Color changes in the skin can occur but are secondary to the inflammatory response, and decreased skin sensitivity does not align with the body's reaction to irritants, as the skin is often more sensitive and reactive in these situations.