Contact allergy to topical corticosteroids--results from the IVDK and epidemiological risk assessment.

Background: Contact allergy (CA) to topical corticosteroids (CS) is relatively rare; however, current data from Germany are not available. Furthermore, valid risk assessment needs to take into account of the actual exposure to CS in the population.
Patients and Methods: The reaction profile of 9 CS included in a "CS test battery" of the German Contact Dermatitis Research Group (DKG) in patients seen in German clinics belonging to the Information Network of Departments of Dermatology (IVDK; http://www.ivdk.org) between 01/1995 and 12/2004 was analyzed. Applying the "Clinical Epidemiology/Drug Utilization Research" approach, annual incidences of CA to CS in Germany were extrapolated. These estimates were used as numerator for a relative incidence (RI) estimate which used exposure in terms of "defined daily doses" (DDD) to the respective CS as denominator, the latter information collected by the AOK Research Institute (WIdO).
Results: On average, 7.4% of all patients were patch tested with the CS series, mostly yielding < 1% positive reactions. Exceptions included hydrocortisone 17-butyrate (1.5%), amcinonide (1.6%) and budesonide (2.6%). With a RI of 10.7, 23.6 and 4.9 per 100,000 DDD, respectively, the three CS mentioned classify as moderate topical drug allergens. Clobetasol 17-propionate and triamcinolone acetonide both yielded a RI of 1.4/100,000 DDD, indicating low sensitization risk. For hydrocortisone, betamethasone, prednisolone and dexamethasone (RI < 1/100,000 DDD) the risk of sensitization appears minute.
Conclusions: The results support and extend previous evidence on the CA risk of CS, adding to a therapeutic index and risk assessment.