What is a contact allergy?

Within the context of an allergic skin disorder, if a dog reacts to certain foreign substances (=allergens) with symptoms such as wheal formation on the entire body, itchiness, particularly on the head, paws and axillae and numerous other forms of skin symptoms, one speaks of a so-called contact allergy. In particular these kinds of allergies are frequently the cause for considerable skin and coat problems.
Typical contact allergies found with dogs come from chemical substances for topical application (e.g. against parasites), chemical substances from detergents, carpets and materials or colours as well as from contact with plant protection agents, for instance after walking through freshly sprayed fields, and even epithelium allergies against the epithelium of mice, rats, chicken etc..