P76 Allergic contact dermatitis vs. psoriasis

Abstract

Background: Psoriasis prevalence in the Spanish population is around 1.4%(2000). The last epidemiological enquire of the GEIDC (2001) showed that 55.11% of the patients revised in specialized units presented Allergic Contact Dermatitis (ACD). Concomitance of both processes has been widely studied being the opinions of the different authors controversial. Palmo‐plantar psoriasis seems to be the most frequent type in patients presenting delayed hypersensitivity.Aim and methods: A retrospective study (2002–2003) of the incidence of ACD in patients previously diagnosed of psoriasis was performed in the allergy unit of our hospital. The aim of our study was to investigate the delayed hypersensitivity among psoriatic patients as well as its clinical relevance in our influence area. 604 consecutive patients were studied. Standard batteries of the GEIDC as well as complementary series (True‐Test and Chemotecnique) were performed. Allergen application and posterior evaluation were done according to the ICDRG rules.Results: We studied 26 patients affected of Psoriasis, (4,3% of total). In contrast to the general population, 9 were female (mean age 49 years) and 17 male (mean age 48,4 years). ACD suggestive lesions were located in the hands of 15 patients, feet in three of them and in 4 patients both. Patch test was negative in 8 cases. The most detected allergens were Nickel and Fragrance‐mix. Occupational origin was discussed in 6 cases. Sensitivity to formaldehyde resins was demonstrated in several patients. Medicamentous origin due to ethylendiamine and Peru Balsam was also demonstrated.Comments: Several revisions about the relationship of ACD and psoriasis have been published in the last years and most of the authors think that there are no differences between healthy, psoriatic and atopic subjects. These studies have focused on adverse drug reactions or standard series of allergens, taking not in consideration an occupational origin. We suggest epicutaneous tests as a reliable method to diagnose ACD in psoriatic patients with chronic and/or refractory lesions in hands.