Background: Sensitization to topical treatments used in leg ulcers is common. Questioning and patch testing are used to identify causative drugs or dressings.
Objectives: To study the current frequency of sensitization in our centre, to analyse previously published studies, and to compare sensitization in recent years with studies published before 1990.
Methods: A retrospective study was undertaken of all patients admitted with leg ulcers in 2001 and 2002. Of the files of 235 patients with leg ulcers reviewed, we identified 106 patients (group A) who had been patch tested in our institution between 2001 and 2002 with the European standard series and an additional series. The frequency of sensitization was compared with an earlier unpublished retrospective study in our centre of 36 leg ulcer patients tested in 1988 (group B), with a group of unselected contact dermatitis patients tested between 1 January 1997 and 31 December 2000 in our centre (group C), and with results published in the literature. We performed a computerized database search of MEDLINE and compared results obtained in recent years with those obtained before 1990 to obtain evidence of changing trends.
Results: Seventy-five per cent of the 106 patients had at least one positive reaction, and 57% had two or more positive reactions. Balsam of Peru was positive in 40% of cases, followed by lanolin (21%), fragrance mix (18%), trichlocarban (13%), colophony (11%), Cetavlon (cetrimide cream) (9%) and neomycin (9%). Thirty-five of the 36 group B patients had at least one positive reaction. Lanolin was the most frequent (31%), followed by balsam of Peru (22%), Cetavlon (19%), colophony (14%), terebenthene (14%), quinoline mix (11%) and benzocaine (8%). Two hundred and eighty-six of 526 patients of group C were positive in at least one test (54.4%). Three allergens gave a sensitization rate >10%: balsam of Peru (12.5%), fragrance mix (15.2%) and nickel sulphate (21.1%). Review of the literature and calculation of sensitization rates in a pool of 3043 patients extracted from 24 series, plus our own, showed persistence of high sensitization rates and a significant (8.5%) increase in sensitization between the two periods compared. There was a decrease in sensitivity to lanolin, constant sensitization to aminoglycosides, a slight increase in sensitivity to thiuram mix and glucocorticoids, and a marked increase in sensitivity to balsam of Peru in France. Newer topical treatments and dressings showed very low rates of sensitivity with the exception of hydrogels.
Conclusions: Despite warnings, sensitization to topical treatments for leg ulcers is still frequent and, moreover, continues to increase, some variations reflecting local nursing practices and variations in topical treatment available. Although a decrease in sensitization rate with lanolin has been observed throughout the world, no decrease in sensitization rate has been demonstrated with aminoglycosides, and sensitization to glucocorticoids, thiuram mix and new products (hydrogels) is now increasingly being reported.