Contact dermatitis in patients with leg ulcers

The incidence of contact allergy to 63 substances, including active principles and excipients used in a variety of topical preparations, has been studied by patch testing in 306 patients being treated conservatively for stasis dermatitis with or without ulceration. Positive reactions to one or more test compounds were recorded in 177 patients. The main offenders among drugs were neomycin, sulphonamide and promethazine; among the excipients, they were parabens, lanolins and benzoyl peroxide. Frequent reactions were observed to certain substances of the 'para' group, benzocaine, diaminodiphenylmethane, aniline and paraphenylendiamine, with the first three acting mainly as indicators of cross-sensitization. The extension and spread of allergic dermatitis can also be produced by drugs administered systematically. Recognition of the allergens responsible for allergic contact dermatitis arising at the lower leg site is a necessary condition if chronicity and spread of the dermatitis are to be prevented. For the same reason it is important to restrict topical applications to non-allergic substances.     

Contact dermatitis in patients with leg ulcers

100 patients with leg ulcers were patch tested against a standard battery of allergens. The readings were carried out daily from the 2nd to the 7th days. 55 patients showed positive reactions to one or more allergens. 32% of positive reactions developed for the first time after 48 h and 11% after 72 h. No single day or combination of two days gave 100% positive results. A single reading on the 4th day gave the highest number of positive reactions at 92%. The prevalence of positive patch tests was significantly higher in patients with surrounding eczema, and in patients with positive patch tests the ulcer duration was significantly longer than in those with negative patch tests. The total number of positive results in individuals increased linearly with the duration of the ulcer. Of allergens to which the ulcer was exposed, the occurrence of multiple sensitivity was significantly greater than predicted from the prevalence of individual sensitivities. However, there was no association between medicaments and metal sensitivity. This, together with the absence of an exponential rise in the number of allergens with the duration of ulcer, does not support the theory of systemic ampliative allergy.     

Contact sensitivity in patients with venous leg ulcers in Serbia: comparison with contact dermatitis patients and relationship to ulcer duration

Background: Contact hypersensitivity is a common occurrence in patients with chronic venous leg ulcers (CVLU) with allergen profiles depending upon the local treatment policies.
Objective: This study was to determine the frequency of contact sensitivity, prevalence of individual allergens, polyvalent sensitization, and/or their relationship to ulcers duration in the population of CVLU and contact dermatitis patients in Serbia.
Patients: 75 patients with CVLU and 82 patients with clinically suspected contact dermatitis were prospectively included in the study. The patients were patch tested with a series of 21 standard and 22 supplemental allergens.
Results: 73% ( n  = 55) of CVLU and 52% ( n  = 43) of control subjects had 1 or more positive patch test results ( P  < 0.01). Polysensitization was found in 53% of patients and 21% of controls ( P  < 0.01). CVLU patients run 2.5 and 4.3 higher risk for contact sensitization and polysensitization, respectively. The most common allergens were Balsam of Peru (21.3%), carba mix (18.7%), fusidic acid (17.3%), colophony (13.3%), paraben mix (12%), chloramphenicol (12%), silver nitrate (12%), and neomycin (10.7%). Polivalent sensitization and higher mean number of allergens were associated with ulcer duration >5 years.
Conclusions: The results confirm a high rate of contact (poly)sensitization in patients with CVLU and local variability in allergen prevalence.     

Contact sensitization in patients with chronic venous leg ulcers in Singapore

Contact sensitization rates are high in patients with chronic venous leg ulcers. Allergic contact dermatitis poses a significant hindrance to the healing of the wounds. There are no published studies examining the rate of contact sensitization in Asian patients. Our objective was to determine the rate of contact sensitization in patients with chronic venous leg ulcer in Singapore and the variation in the common allergens based on local practices in comparison with Western countries. 44 patients were patch tested to the National Skin Centre standard series, steroid series, medicaments, topical Chinese medicaments, and to modern wound dressings used. The overall rate of contact sensitization was 61.4%. The common allergen groups were topical antibiotics (18.2%) and topical traditional Chinese medicaments (TTCM) (15.9%). Individually, colophony (11.3%), Saw Hong Choon skin ointment (Kam Bo Med, Hong Kong, Hong Kong) (11.3%), Balsam of Peru (9.1%), and povidone iodine (9.1%) were among the most frequent allergens. The sensitization rate among users of TTCM was notably high (41%). A high rate of contact sensitization was found in our study, similar to previous reports from the West. TTCM play a major role as possible allergens in our patients. In Asian patients, a history of its usage should be elicited, and patch testing should include the commonly used TTCM where possible.     

Contact allergy to aeroallergens in children with atopic dermatitis: comparison with allergic contact dermatitis

Immediate and delayed cutaneous hypersensitivity are believed to be implicated in the physiopathology atopic dermatitis (AD). The purpose of this study was to evaluate Type I and Type IV allergy to aeroallergens in children with AD. 59 children (mean age 5.2 years), presenting with AD according to Hanifin and Rajka's criteria, were skin tested (patch and corresponding prick tests) with common environmental aeroallergens and a restricted panel of the European standard series over a 1-year period. History and clinical data were carefully recorded using a standardized evaluation sheet: total and specific IgE serum levels were evaluated 17 of 59 patients (28.8%) had at least 1 positive patch test, 32 of 59 patients (54.2%) had at least 1 positive prick test. Corresponding patch and prick tests were observed in 8 out of 17 patients. 5 children with positive patch tests had negative prick tests. Irritant pustular reactions (2/59, i.e. 3%), "angry back" reactions (6/59, i.e. 10%) and doubtful reactions (3/59, i.e. 5%) were excluded from the positive group. Positive patch tests observed included, in decreasing order: D. pteronyssinus and D. farinæ (26.8%) garden trees (12.2%), plantain (9.8%), timothy grass, mugwort and damp area trees (4.9% each), and orchard grass (2.44%). 6 children with positive aeroallergen patch tests and 11 children with negative aeroallergen patch tests had at least 1 positive patch test to standard allergens. All children with an irritant reaction to aeroallergens had no reaction to standard patch tests. The relevance of aeroallergens in upgrading the severity of AD lesions has still to be explored by challenge studies and by long-term follow-up.     

Contact allergy in patients with chronic venous leg ulcers-- possible role of chronic venous insufficiency

The purpose of this study was to evaluate frequency of contact allergy in patients with chronic venous leg ulcers (CVLU) and to estimate possible relationships between allergic contact reactions and characteristics of both chronic venous insufficiency (CVI) and CVLU. We performed patch tests with the European standard series, antibiotics, glucocorticosteroids and ointment vehicles in 50 patients with CVLU. Patients underwent detailed CVI diagnostics using colour flow duplex ultrasound examination, ankle brachial pressure index determination and leg ulcers area measurement. Positive patch tests results were found in 80% and polyvalent allergy in 56% of patients. Statistically significant correlations were recorded between CVI and CVLU duration, CVLU duration and CVLU area and between CVI duration and polyvalent allergy frequency. Statistically significant differences were observed between coexistence of superficial and deep system insufficiency and CVLU duration, characteristics of contact allergic reactions and CVI duration, frequency of allergic contact reaction and presence or absence of long saphenous vein insufficiency, incidences of vein thrombosis and characteristics of contact allergic reactions as well as between characteristics of contact allergic reactions and both CVLU duration and area. Complex pathophysiological processes, including inflammatory reactions, in course of CVI may influence development of allergic contact reaction in CVLU patients.     

Contact allergy to Dermatophagoides in atopic dermatitis patients and healthy subjects

To compare different house-dust-mite-derived allergenic materials and to correlate the presence of IgE LO Dermatophagoides with patch test results, 313 atopic dermatitis (AD) patients and 100 healthy volunteers (HV) underwent patch tests with: Dermatophagoides Pteronyssimus (DPT) lyophilized purified alpha fraction in buffered saline/glycerol 50% and or in petrolatum (Bayropharm); 540% DPT and 50% Dermatophagoides farinae (DF) whole bodies in petrolatum and petrolatum oil (Allergopharma-Bracco); DPT and DF whole bodies in petrolatum and petrolatum oil (Lofarma). We found 39% positive reactions among AD subjects and 13% in HV The presence of serum-specific IgE did not influence the patch test results. with of AD patch-lest-positive patients and 5 of 13 HV respectively, showed a positive prick less and or RAST lo Dermatophagoides. Similar sensitization rates were observed with the allergenic material from Bayropharm (54% positivities) and Allergopharma-Bracco (51% positivities), whereas the preparations from Lofarma gave a 20% response rate.     

The frequency of contact allergy in atopic patients with dermatitis

A prospective study was performed to establish the frequency of contact allergy in atopic patients presenting with dermatitis, compared with non-atopics suffering from dermatitis. During 1987-1988, all new patients aged 15 years or older, who consulted us for dermatitis, were investigated. They were patch tested with the European standard series, methyl(chloro)isothiazolinone and other relevant allergens. In addition, they were prick tested with 24 inhalant and 11 food allergens. Patients having at least 2 positive prick tests, and patients with 1 positive prick test and a (family) history of atopic diseases were defined as atopics, as were those who presented with classic atopic dermatitis but with negative prick tests. 499 patients were evaluated: 159 men and 340 women. 214 patients (43%) were atopic, the other 285 (57%) were non-atopic. In the atopic group, 79 persons (37%) had at least 1 positive patch test reaction. In the group of non-atopics, 149 patients (52%) had contact allergies. The difference is statistically significant (chi 2; p less than 0.05). It is concluded that adult atopics seen in dermatological practice who present with dermatitis are less frequently contact sensitized than such patients who are non-atopic. Nevertheless, a yield of nearly 40% positive patch test reactions in this group still makes routine patch testing necessary.     

Allergic contact dermatitis in venous leg ulcer patients

Our aim was to determine the frequency and nature of contact sensitivity in venous leg ulcer patients in Lanarkshire. We performed patch testing with the European standard series, antimicrobials and medicaments on 200 patients referred to our leg ulcer clinics. Positive patch tests were found in 136 (68%) patients. Multiple allergies occurred in 102 (51%). The most frequent allergen groups were fragrances (30.5%), antimicrobials (19.5%), topical excipients (19.5%), rubber accelerators (13.5%) and topical corticosteroids (8%). We also found a high prevalence of positive patch tests to Intrasite gel (9.5%) and Hioxyl cream (8.5%), medicaments which are commonly used to treat leg ulcers in our area. Contact sensitivity is common in venous leg ulcer patients and has important implications for patient management. The allergens involved vary depending on local nursing practice. We suggest that all venous leg ulcer patients be patch tested with a locally relevant patch test series.     

Contact allergens in patients with leg ulcers

Background Contact dermatitis can complicate the treatment of leg ulcers and is an acquired phenomenon resulting from the use of topical medications.
Objective To show the incidence of contact dermatitis reactions to topical medications applied to leg ulcers and to evidence changing trends in such reactions through comparison of two case series about 20 years apart.
Subjects and methods We studied two groups of patients with leg ulcers that were patch tested with contact allergens in 1973–1974 and in 1994–1995.
Results One or more positive patch tests was present in 75% and 40% of the patients, respectively. A decrease in the incidence of positive reactions to neomycin, local anesthetics and parabens mix was seen in 1994–1995. The most important contact allergens in 1994–1995 were fragrance mix, colophony and the excipients wool alcohols and amerchol. Other relevant sensitizers were formaldehyde, neomycin and gentamycin.
Conclusion The changing trends in contact allergens over the last 20 years may be explained by changes in the components of topical agents used for treatment.     

The role of contact allergy to aeroallergens in atopic dermatitis

In some patients with atopic dermatitis (AD), delayed-type allergy to aeroallergens, such as house dust mite, can be demonstrated by patch testing. Positive patch tests can be expected only in patients with AD and, in them, only to aeroallergens to which type 1 reactions have also been demonstrated. In an as yet unknown number of such cases, aeroallergens appear to play a role in AD. Studies to date have varied too widely in experimental method and design to allow more definite conclusions to be drawn. It is essential that future studies are standardised with regard to patch test system and designed to include adequate controls and assessment of relevance.     

The spectrum of contact allergy in elderly patients with and without lower leg dermatitis

BACKGROUND: There is a strong influence of lower leg dermatitis on the spectrum of allergic contact sensitivity in elderly patients. OBJECTIVE: To quantitatively assess the impact of this factor which confounds the age-related pattern of allergic contact sensitivity. METHODS: Stratified analysis of allergic contact sensitivity data collected between 1996 and 1999 in the 32 centres of the Information Network of Departments of Dermatology (three age groups: < or =60, 61-75, > or =76 years), both as crude and as directly standardised (for sex and leg dermatitis) proportions. RESULTS: Among the 36,070 patients tested with the German standard series, allergic contact sensitivity to neomycin, lanolin, cetostearylic alcohols, colophony, fragrance mix and balsam of Peru, among others, was (much) more common in the elderly, with proportions more or less affected by standardisation. CONCLUSION: The comparison of crude and standardised proportions provides evidence that allergic contact sensitivity to several allergens strongly depends not only on age itself, but on age-related and thus confounding co-morbidity.