Patch Test, Skin Allergies 

Patch testing is normally required to confirm an allergic or irritant reaction to a suspected allergen. However, if the physician's suspicion and the pattern of the inflammation on the skin (exposure pattern) support the association between an allergen and a patient's dermatitis, simply avoiding the suspected allergen may suffice. For example, if a patient has a rash only on the earlobe and wrist, perhaps a nickel allergy may be considered due to the use of earrings and watches.