ABSTRACT
Topical corticosteroids (CS) are widely used in dermatology because of their anti-inflammatory, anti-proliferative and immuno-suppressive properties. On the other hand, the prolonged application of corticosteroids may induce adverse reactions such as allergic contact dermatitis (ACD). Patch testing CS often poses methodological issues correlated to their drug properties that may hide the manifestations of a positive reaction. Furthermore, the ideal concentration to patch test corticosteroid is still a matter of study and some vehicles have some well-known limitations. This article is divided into two parts: the first one investigated vehicles that may efficiently dissolve the corticosteroids, according to the polarity of the latter; the second part compared the results of the patch tests with hydrocortistone-17-butyrate using two different vehicles: ethanol, which is the standard one, and another vehicle selected as suitable from our CS solubility test.
Subject(s)
Dermatitis, Allergic Contact/diagnosis , Hydrocortisone/immunology , Patch Tests/methods , Pharmaceutical Vehicles , Adult , Aged , Female , Humans , Male , Middle AgedABSTRACT
Allergic contact dermatitis (ACD) and photo-ACD are cell-mediated delayed hypersensitivity reactions of the skin caused by a wide range of substances. Topical ketoprofen (KP), a nonsteroidal anti-inflammatory drug (NSAID), can induce ACD and photo-ACD. Patients with ACD and/or photo-ACD to KP frequently show concomitant sensitization to other substances. The aim of this study was to identify the substances most frequently associated with sensitization to KP, and to evaluate, by means of computerized conformational analysis, whether this association could be due to cross-allergy. 15 subjects with ACD and photo-ACD to KP were tested with the SIDAPA (Società Italiana di Dermatologia Allergologica Professionale ed Ambientale) patch test standard series, including fragrance mix and its components (eugenol, isoeugenol, oak moss, geraniol, hydroxycitronellal, amylcinnamaldehyde, cinnamyl alcohol and cinnamaldehyde) and with the SIDAPA photopatch test series. Allergic reactions to cinnamyl alcohol were noted in all patients, whereas some patients also showed positive reactions to fenticlor, octocrylene and benzophenone-10. Computerized conformational analysis demonstrated that the structure of cinnamyl alcohol is similar to that of KP, whereas the structures of benzophenone-10, octocrylene and fenticlor are completely different. These results suggest that in patients with contact allergy to KP, concomitant positive reactions to cinnamyl alcohol are due to cross-sensitization, whereas simultaneous allergic reactions to fenticlor, octocrylene and benzophenone-10 should be regarded as co-sensitizations.
