Drug-induced contact dermatitis: an update and advice concerning the prescriptions of systemic drugs.

Drug contact dermatitis can induce a systemic cutaneous adverse drug reacti on following systemic challenge with the drug. Clinical features of systemi c contact allergy are various e.g. generalized eczema, Baboon syndrome, pom pholyx, maculopapular rash... Systemic challenge with the drug responsible can also induce reactivation of contact eczema (flare-up). Systemic contact dermatitis has been described for example with corticosteroids, imidazoles , anti-metabolites, heparin, aciclovir or propacetamol. Thimerosal-positive patients, if sensitized to thiosalicylic acid (one of the sensitizing moie ties of this preservative) have a high risk of develvoping a photosensitiza tion to piroxicam. A review of the literature concerning contact dermatitis due to drugs, cross-reactions between drugs with chemical similarities and the risk of inducing systemic contact dermatitis with drugs is preserved. Knowledge about the risk of systemic contact dermatitis due to the excipien ts or the drug itself is important to keep in mind to advise he patients wh o have previously developed drug-induced contact dermatitis.