In some cases, medicated patches can cause skin irritation . These phenomena occur especially in people who have very sensitive skin: the treated area may redden, itch or become covered with vesicles full of serum. This side effect could only depend on the application of the patches . In this case, it is sufficient to pay more attention during the handling and positioning of the product (the package insert attached to the drug indicates precisely how and where to make the patch adhere to the skin).
In the case of an allergic reaction to the active ingredient, however, the irritative skin phenomena are more extensive and do not disappear even when the place of application is changed. In this case, you must immediately remove the transdermal device, wash the part and consult your doctor, who can propose to ascertain the cause with the allergy tests and change the formulation of the drug.
Particular attention must be paid to ketoprofen- based pain relieving patches, as they can induce serious phototoxic and allergic reactions if associated with direct sunlight or exposure to artificial UVA sources. These effects seem to be caused by the interaction of the active principle with UV radiation, responsible for the formation of dangerous and harmful free radicals for the skin, including benzoylphenylethane. Skin reactions can manifest with severe itching, burning, erythema (redness), vesicles and blisters that can extend even beyond the area of application. In some cases, the consequences can be systemic and so severe as to require the person's hospitalization.
For this reason, the European health authorities have published a press release in which they recommend those who use ketoprofen-based drugs for topical use to wash their hands thoroughly after each application and to avoid exposing them to light during treatment and two weeks following the interruption of the same. To minimize the risk of such adverse reactions, doctors and pharmacists are also advised to inform patients about the correct use and possible risks of the patches that contain this active ingredient.
