Contact allergy in chronic leg ulcers: results of a multicentre study carried out in 423 patients and proposal for an updated series of patch tests

Polysensitization in the Spanish Contact Dermatitis Registry (REIDAC): A 2019-2022 prospective study with cluster and network analysis

BACKGROUND

There is still limited clinical-practice data on specific clinical and patch test features, as well as on allergen clusters in polysensitization (PS).

OBJECTIVES

To determine the frequency, relevance, symptoms duration and risk factors in polysensitized patients and to assess possible allergen aggregation.

METHODS

Prospective multicentric study (January 2019-December 2022) conducted in setting of the Spanish Contact Dermatitis Register (REIDAC). Clinical and patch test data of polysensitized and oligosensitized patients were compared, and risk factors of PS were investigated with logistic multivariate regression. Unsupervised hierarchical clustering and network analysis were used to study allergen aggregation in PS.

RESULTS

A total of 10,176 patients were analysed. PS was found in 844 (8.3%). Current relevance was significantly higher in polysensitized patients (p < 0.01). Risk factors for PS were atopic dermatitis (OR: 1.58, 95% CI: 1.24-2.02), age (≥60 years vs. ≤24 years, OR: 1.75, 95% CI: 1.25-2.44) and some special locations (legs vs. face OR: 1.54, 95% CI: 1.05-2.25, hands vs. face OR: 1.46, 95% CI:1.15-1.85, arms vs. face OR: 1.49, 95% CI:1.01-2.20, trunk vs. face OR: 1.40, 95% CI:1.06-1.85). Cluster and network analyses revealed specific-allergen clusters and significant associations, including allergens belonging to metals group, fragrances and botanicals group, topical drugs group, rubber allergens and biocides.

CONCLUSIONS

This study confirms that PS is structured by discernible patterns of specific-allergen clusters and reinforces significant allergen associations in PS. Cross-reactivity and/or concomitant sensitization could explain the formation of allergen clusters in PS.

Potential Allergens in Wound Care Products

Background: Patients with chronic wounds have an increased risk of developing allergic contact dermatitis (ACD). Reports of ACD to wound care products are not uncommon. To minimize contact sensitization in patients with chronic wounds, allergenic ingredients should be avoided when possible. Objective: With more than 5000 wound care products available in the United States, it is essential to understand which products can be chosen to minimize allergen exposures. Methods: Ingredients in wound care products in 5 wound care clinics across 2 institutions were cross-referenced with the American Contact Dermatitis Society core allergen series 2020. Results: Of the 267 wound care products included, 97 (36.3%) contained at least one allergen, including 31 dressings/wraps (22.3%), 25 medications (69.4%), 12 cleaning supplies (36.3%), 16 tapes/glues (80%), 2 instruments (14.3%), 8 emollients and vehicles (61.5%), 1 ostomy product (11.1%), and 2 odor-eliminating products (66.7%). Thirty-four different allergens were identified across all products. The most common allergens present in the included items were acrylates and propylene glycol, followed by parabens, cetyl stearyl alcohol, tocopherol, fragrance, and phenoxyethanol. Conclusions: Many wound care products contain at least one contact allergen, highlighting the importance of clinician education on ACD in the context of wound care product selection.

Lanolin

Lanolin is a complex mixture of high molecular weight esters, aliphatic alcohols, sterols, fatty acids, and hydrocarbons that has been widely used for centuries for its emollient properties. The purification of crude lanolin into lanolin wax and the processing of this wax into various derivatives began in 1882 and continue to this day with newer highly purified anhydrous lanolins. Controversy as to lanolin's allergenicity began in the 1920s and remains an issue. The most appropriate patch test preparation(s) for detecting allergy remain disputed. Detection of lanolin-induced contact dermatitis in diseased skin by patch testing on normal skin may lead to false negative results. Patients with a positive patch test to lanolin may tolerate use of lanolin on normal skin. Although lanolin is a weak sensitizer and the frequency of contact allergy to it in the European population reportedly is 0.4%, there are high-risk concomitant conditions: stasis dermatitis, leg ulcers, perianal/genital dermatitis, and atopic dermatitis (AD). Children and the elderly are also at greater risk of developing contact allergy to lanolin, partly because of comorbidities (AD and stasis dermatitis/leg ulcers, respectively). Finally, in the United States, non-Hispanic white patients are more likely than their non-Hispanic black counterparts to be lanolin allergic.

Potential Allergens in Wound Care Products

BACKGROUND

Patients with chronic wounds have an increased risk of developing allergic contact dermatitis (ACD). Reports of ACD to wound care products are not uncommon. To minimize contact sensitization in patients with chronic wounds, allergenic ingredients should be avoided when possible.

OBJECTIVE

With more than 5000 wound care products available in the United States, it is essential to understand which products can be chosen to minimize allergen exposures.

METHODS

Ingredients in wound care products in 5 wound care clinics across 2 institutions were cross-referenced with the American Contact Dermatitis Society core allergen series 2020.

RESULTS

Of the 267 wound care products included, 97 (36.3%) contained at least one allergen, including 31 dressings/wraps (22.3%), 25 medications (69.4%), 12 cleaning supplies (36.3%), 16 tapes/glues (80%), 2 instruments (14.3%), 8 emollients and vehicles (61.5%), 1 ostomy product (11.1%), and 2 odor-eliminating products (66.7%). Thirty-four different allergens were identified across all products. The most common allergens present in the included items were acrylates and propylene glycol, followed by parabens, cetyl stearyl alcohol, tocopherol, fragrance, and phenoxyethanol.

CONCLUSIONS

Many wound care products contain at least one contact allergen, highlighting the importance of clinician education on ACD in the context of wound care product selection.

Quaternary ammonium compounds in hypersensitivity reactions

Quaternary ammonium compounds (QAC) are commonly used disinfectants, antiseptics, preservatives, and detergents due to their antibacterial property and represent the first used biocides before phenolic or nitrogen products. Their common structure consists of one or more quaternary ammonium bound with four lateral substituents. Their amphiphilic structure allows them to intercalate into microorganism surfaces which induces an unstable and porous membrane that explains their antimicrobial activity towards bacteria, fungi, and viruses. QAC are thus found in many areas, such as household products, medicines, hygiene products, cosmetics, agriculture, or industrial products but are also used in medical practice as disinfectants and antiseptics and in health care facilities where they are used for cleaning floors and walls. QAC exposure has already been involved in occupational asthma in healthcare workers or professional cleaners by many authors. They also have been suggested to play a role in contact dermatitis (CD) and urticaria in workers using cosmetics such as hairdressers or healthcare workers, inciting reglementary agencies to make recommendations regarding those products. However, distinguishing the irritant or sensitizing properties of chemicals is complex and as a result, the sensitizing property of QAC is still controverted. Moreover, the precise mechanisms underlying the possible sensitization effect are still under investigation, and to date, only a few studies have documented an immunological mechanism. Besides, QAC have been suggested to be responsible for neuromuscular blocking agents (NMBA) sensitization by cross-reactivity. This hypothesis is supported by a higher prevalence of quaternary ammonium (QA)-specific IgE in the professionally exposed populations, such as hairdressers, cleaners, or healthcare workers, suggesting that the sensitization happens with structurally similar compounds present in the environment. This review summarizes the newest knowledge about QAC and their role in hypersensitivities. After describing the different QAC, their structure and use, the most relevant studies about the effects of QAC on the immune system will be reviewed and discussed.

Allergies and COVID-19 vaccines: An ENDA/EAACI Position paper

BACKGROUND

Anaphylaxis, which is rare, has been reported after COVID-19 vaccination, but its management is not standardized.

METHOD

Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed.

RESULTS

No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine are excipients. The authors propose allergy evaluation of persons with the following histories: 1-anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2-anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine; and 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left-over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable.

CONCLUSIONS

These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated.

102 cases of sensitization to an antiseptic containing chlorhexidine digluconate/benzalkonium chloride/benzyl alcohol with different profiles of sensitization in adults and children

BACKGROUND

An aqueous antiseptic containing "chlorhexidine digluconate /benzalkonium chloride /benzyl alcohol" (CBB) is widely used in France. The only previous documented study dealing with allergic contact dermatitis to this antiseptic is one small case series in children. The French Vigilance Network for Dermatology and Allergy (REVIDAL-GERDA) has collected many cases in the last few years.

OBJECTIVES

To evaluate the clinical and sensitization profiles of patients diagnosed with allergic contact dermatitis to CBB.

METHODS

We performed a retrospective study of patients with contact dermatitis to CBB and positive tests to CBB and/or at least one of its components. All patients had to be tested with all components of CBB.

RESULTS

Seventy-one adults and thirty-one children were included. The lesions were extensive in 63 % of patients and 55% had delayed time to diagnosis. CBB patch tests were positive in 93.8% of cases. The allergen was identified in 97% of patients, mainly benzyl alcohol in adults (81.7%), and chlorhexidine digluconate in children (54.8%). 32.4% of the patients were sensitized to several components.

CONCLUSION

CBB is a cause of allergic contact dermatitis at all ages. The antiseptic's components should be tested. The sensitization profile seems to be different between adults and children. This article is protected by copyright. All rights reserved.

Prevalence and trend of allergen sensitization in patients with a diagnosis of stasis dermatitis referred for patch testing, North American contact dermatitis group data, 2001-2016

BACKGROUND

Few studies explored the relationship between stasis dermatitis (SD) and allergic contact dermatitis (ACD).

OBJECTIVE

To examine trends, associations, and clinical relevance of ACD in patients referred for patch testing who had a final SD diagnosis.

METHODS

Retrospective analysis from 2001 to 2016 of 38,723 patients from the North American Contact Dermatitis Group.

RESULTS

After patch testing, 303 (0.7%) patients were diagnosed with SD; 46.7% had a concomitant diagnosis of ACD. Patients with vs. without a final SD diagnosis had similar proportions of ≥ 1 positive allergic reaction (59.7% vs. 64.7%; Chi-square, P = 0.0724) but higher odds of allergic reactions to fragrance mix I, bacitracin, quaternium-15, Myroxylon pereirae, benzalkonium chloride, ethyleneurea melamine formaldehyde, diazolidinyl urea, and propylene glycol. The most commonly relevant allergens in patients with final SD diagnosis were fragrance mix I, Myroxylon pereirae, bacitracin, quaternium-15, and formaldehyde. The most common allergen sources were personal care products, topical medications and other health aid products.

CONCLUSION

Nearly half of patients with a final SD diagnosis were also diagnosed with ACD, supporting the role of patch testing in select SD patients.

Allergic contact versus irritant contact dermatitis in patients with hard-to-heal leg ulcer: clinical and diagnostic approach

BACKGROUND

Dermatitis of surrounding skin may complicate hard-to-heal leg ulcers, delaying wound healing. The coexistence of hard-to-heal leg ulcers and irritant or allergic contact dermatitis may create difficulties for both diagnostic and therapeutic management.

OBJECTIVE

The aim of our study was to evaluate the incidence of dermatitis occurring in the surrounding skin in a population affected by hard-to-heal leg ulcers during treatment, and to differentiate between allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) with the use of a patch test. Furthermore, we investigated which medications were most probably related to these conditions.

METHOD

We conducted an observational study from 21 February to 21 July 2017, enlisting all patients affected by hard-to-heal leg ulcers who attended the Wound Care Service of the Dermatologic Department of ASST, Spedali Civili, Brescia, Italy.

RESULTS

We enrolled 95 patients; 81 patients did not develop dermatitis, while 14 patients developed dermatitis of the surrounding skin. These patients underwent a patch test which gave a positive result in seven patients, permitting the diagnosis of ACD.

CONCLUSION

Our study confirmed the incidence of dermatitis of the surrounding skin reported in the literature but reassessed the incidence of ACD as opposed to ICD.

Patch testing with sodium disulfite: North American Contact Dermatitis Group experience, 2017 to 2018

BACKGROUND

Sodium disulfite (SD), also known as sodium metabisulfite, is an increasingly recognized cause of allergic contact dermatitis.

OBJECTIVES

The objective of this work was to characterize individuals with positive patch test reactions to SD as well as analyse reaction strength, clinical relevance, and sources.

METHODS

This is a retrospective analysis of patients patch tested with SD (1% petrolatum) by the North American Contact Dermatitis Group (NACDG), 2017 to 2018.

RESULTS

Of 4885 patients patch tested with SD, 132 (2.7%) had a positive reaction. Common primary anatomic sites of dermatitis were face (28.8%), hands (20.5%), and a scattered/generalized distribution (13.6%). Compared with SD-negative patients, SD-positive patients were more likely male (odds ratio 2.81, 95% confidence interval 1.98-4.00) and/or over 40 years (odds ratio 1.95, 95% confidence interval 1.30-2.94). Reactions were most commonly + (50.4%) or ++ (34.1%); 65.2% were considered currently relevant. About 15.2% were definitively confirmed in sources, commonly personal care products (18.9%, especially hair dye), and drugs/medications/alcoholic beverages (9.1%). Only 2.3% of positive reactions were linked to occupation.

CONCLUSIONS

Positive reactions to SD occurred in 2.7% of tested patients. Reactions were often clinically relevant and linked to personal care products and drugs/medications/alcoholic beverages.

Contact allergy and allergic contact dermatitis from benzalkonium chloride in a tertiary dermatology center in Melbourne, Australia

BACKGROUND

Benzalkonium chloride (BAK) is a quaternary ammonium compound that is used widely as an antiseptic and preservative. It is a strong irritant and considered a weak sensitizer.

OBJECTIVE

To analyze the temporal trend of BAK sensitization and the demographics of sensitized patients.

METHODS

We conducted a single-center retrospective study of 7390 patients who were patch tested with BAK between January 1, 2003 and December 31, 2019.

RESULTS

Of the 7390 patients who were patch tested to BAK, 108 (1.5%) had a positive reaction, with 21 reactions deemed clinically relevant (0.3% of total patch tested) and a further 5 doubtful reactions deemed clinically relevant, resulting in a total of 26 relevant reactions (0.4% of total patch tested). Common sources of exposure were ophthalmic drops (30.8%), topical antiseptic preparations (26.9%), cosmetics (15.4%), disinfectant solutions (11.5%), hand sanitizers (11.5%), and hand washes (7.7%). One fifth of patients with relevant reactions were health care workers. There has been a dramatic increase in the number of positive reactions since 2017, for reasons not totally clear.

CONCLUSION

Contact allergy (CA) and allergic contact dermatitis (ACD) in response to BAK are now increasing at our center. Awareness of this trend is important, given that the coronavirus disease 2019 (COVID-19) pandemic is likely to further expose people to BAK.

Surrounding skin management in venous leg ulcers: A systematic review

OBJECTIVES

Chronic venous insufficiency may lead to the development of venous leg ulcers, the most common form of chronic wounds in the lower extremity. Key to venous leg ulcer care is the maintenance of healthy skin surrounding the ulcer, as failure to maintain skin integrity may influence the healing outcome. We thus reviewed the scientific literature looking for assessment and management instruments regarding this common but often neglected issue.

METHOD

The search included all studies published between 2000 and May 2019. Keywords used were: "peri-wound skin care", "surrounding skin venous ulcers", "surrounding skin management leg ulcers", and "peri-lesional skin management".

RESULTS

Management of moisture-balance with the selection of appropriate dressings is the most important target in surrounding-wound skin care. Moreover, contact dermatitis related to products and the dressings themselves is a neglected problem in patients with chronic leg ulcers which clinicians increasingly have to manage. The literature search revealed that there is an increasing interest in the use of noninvasive assessment tools in the field of wound care, and focusing on the surrounding-wound skin plays a role in assessing the potential of wound healing. Transepidermal water loss measurement (TEWL) and ultrasonography are two of the measurement techniques available.

CONCLUSION

The integrity of the surrounding skin is necessary for wound healing, and appropriate management is needed to address this aspect which is part of an overall approach to treating wounds.

The Treatment of Low Leg Nonischemic Ulcers With a Traditional Chinese-Pharmaceutical Medium: A Randomized Controlled Multicenter Clinical Study

The aim of this study was to observe the curative effect and mechanism of Shengji Yuhong ointment in the healing of chronic ulcer of lower limbs. 400 patients were equally divided into treatment group and control group. The treatment group was covered with a piece of Shengji Yuhong ointment gauze, while the control group was covered with a piece of Vaseline gauze. Both groups changed dressings every other day for 4 weeks. On the 3rd, 7th, 14th, 21st, and 28th days of treatment, the reduction rate of wound area and the growth of wound granulation were observed and the levels of hydroxyproline and hemoglobin in wound granulation tissue were measured. The total effective rate was 99.00% in the treatment group and 71.00% in the control group. The treatment group was significantly better than the control group ( P < .01). The ulcer area reduction rate of the treatment group was significantly higher than that of the control group ( P < .01). The scores of ulcer depth, granulation color, and coverage area on the 7th, 14th, 21st, and 28th days after treatment in the treatment group were significantly lower than those before treatment ( P < .05). After treatment, the levels of hydroxyproline and hemoglobin in granulation tissue of wounds in both groups were significantly higher than those before treatment ( P < .01), and the levels in the treatment group were significantly higher than those in the control group ( P < .01). Shengji Yuhong ointment can improve the healing rate of chronic ulcer of lower limbs.

[Frequency of contact sensitization to modern dressings used to treat chronic leg ulcer]

INTRODUCTION

Allergic contact dermatitis around chronic leg ulcers (CLU) is a common complication in patients presenting CLU and prolongs healing times. The aim of this study was to describe the rate of sensitization to modern dressings (MD) used in these patients and to assess whether there is a relation between the number of sensitizations and ulcer type, the time from onset of the ulcer, and patient age and gender.

PATIENTS AND METHODS

We conducted a retrospective study at Reims University Hospital between 2010 and 2014 that included all patients with CLU of vascular etiology surrounded by eczematous lesions, and who had one of the patch-tests in the following 3 series: European baseline±leg ulcers±corticosteroids.

RESULTS

Among the 73 patients included, 43 % were polysensitized. Thirty-three patients (45 %) were sensitized to MD (38 % to hydrocolloids, 18 % to hydrogels, 7 % to hydrocellular dressings, 7 % to hydrofiber dressings, 5 % to contact layers and 3 % to alginates). Median age and sex did not differ between "polysensitized" patients and "non-polysensitized" patients (P=0.84 and P=0.25, respectively). Polysensitization was more frequent among patients presenting ulcers for more than 5 years (P=0.032).

CONCLUSION

Practically half of all patients presenting CLU with surrounding contact dermatitis had sensitization to modern dressings (mostly hydrocolloids and hydrogels). The rate of sensitization increased with the length of presence of CLU.

An unusual presentation of a common condition: Allergic contact dermatitis

Allergic contact dermatitis commonly affects patients with chronic venous leg ulcers and can contribute to impaired wound healing. Many allergens have been identified, and despite the use of advanced dressings, the incidence of allergy has remained high. We discuss an unusual presentation of allergic contact dermatitis in a patient with a chronic wound. The patient's history was consistent with a recurrent venous leg ulcer, but on this occasion, the wound continued to deteriorate despite optimal treatment. This prompted further investigation, which included patch testing. Although the clinical features were not suggestive of allergy, the patch test was positive for several allergens, including Atrauman^® dressings, which the patient was using at the time. This case highlights the importance of regular reassessment and accurate diagnosis for the management of chronic wounds. It also demonstrates that allergic contact dermatitis can contribute to delayed wound healing without causing the classical clinical features of inflammation of the surrounding skin, and even hypoallergenic, non-adherent dressings can be sensitising.

Contact sensitivity in patients with venous leg ulcer: A multi-centric Indian study

Venous leg ulcers are the most common form of non-healing leg ulcers. They are subjected to treatments such as topical medications, dressings, and compression therapies. This can lead to exposure to a number of allergens with subsequent sensitisation and contact dermatitis of the regional skin. This may contribute to the poor ulcer healing. To detect the various contact sensitisers in patients with venous leg ulcers through patch testing, patients from 6 centres across India with venous leg ulcers of longer than 6 weeks duration were enrolled for the study. They were patch tested using a special parch test kit with 27 antigens. A total of 172 patients were included in the study; 82 (48.2%) tested positive for at least 1 antigen. Among them, polyvalent sensitisation was noted in 71% of patients. Wood tar mix (10.4%) and the framycetin (8.7%) were the most common allergens. There is a high frequency of allergic sensitisation to various ingredients of topical therapies used in the venous ulcer management, which may interfere with wound healing. Avoiding them can help obtain a better therapeutic outcome.

Wound-Related Allergic/Irritant Contact Dermatitis

PURPOSE

To provide information from a literature review about the prevention, recognition, and treatment for contact dermatitis.

TARGET AUDIENCE

This continuing education activity is intended for physicians and nurses with an interest in skin and wound care.

OBJECTIVES

After participating in this educational activity, the participant should be better able to:1. Identify signs and symptoms of and diagnostic measures for contact dermatitis.2. Identify causes and risks for contact dermatitis.3. Select appropriate treatment for contact dermatitis and its prevention.

ABSTRACT

Contact dermatitis to wound care products is a common, often neglected problem. A review was conducted to identify articles relevant to contact dermatitis.A PubMed English-language literature review was conducted for appropriate articles published between January 2000 and December 2015.Contact dermatitis is both irritant (80% of cases) or allergic (20% of cases). Frequent use of potential contact allergens and impaired barrier function of the skin can lead to rising sensitization in patients with chronic wounds. Common known allergens to avoid in wound care patients include fragrances, colophony, lanolin, and topical antibiotics.Clinicians should be cognizant of the allergens in wound care products and the potential for sensitization. All medical devices, including wound dressings, adhesives, and bandages, should be labeled with their complete ingredients, and manufacturers should be encouraged to remove common allergens from wound care products, including topical creams, ointments, and dressings.

The current spectrum of contact sensitization in patients with chronic leg ulcers or stasis dermatitis - new data from the Information Network of Departments of Dermatology (IVDK)

BACKGROUND

Patients with lower leg dermatitis, chronic venous insufficiency or chronic leg ulcers have a high prevalence of contact sensitization.

OBJECTIVES

To identify the current spectrum of contact allergens in these patients.

PATIENTS AND METHODS

Data of the Information Network of Departments of Dermatology on 5264 patients with the above diagnoses from the years 2003 to 2014 (study group) were compared with data on 4881 corresponding patients from 1994 to 2003 (historical control group) and with a current control group without these diagnoses (n = 55 510).

RESULTS

Allergic contact dermatitis was diagnosed less frequently in the study group than in the historical control group (25.9% versus 16.9%; p < 0.001), and contact sensitization to most allergens had declined. The allergen spectrum, however, was largely unchanged. Important allergens are Myroxylon pereirae (balsam of Peru) (14.8% positive reactions), fragrance mix I (11.4%), lanolin alcohol (7.8%), colophonium (6.6%), neomycin sulfate (5.0%), cetearyl alcohol (4.4%), oil of turpentine (3.1%), and paraben mix (2.6%). Patch testing with additional series showed sensitization to Amerchol L-101 (9.7%), tert-butyl hydroquinone (8.7%), framycetin sulfate (5.0%), and gentamicin sulfate (3.1%).

CONCLUSIONS

Topical preparations for treating the above-mentioned conditions should not contain fragrances, Myroxylon pereirae, and colophonium. The special allergen spectrum has to be considered in patch testing.

Contact Dermatitis for the Practicing Allergist

This article provides an overview of important practice recommendations from the recently updated Contact Dermatitis Practice Parameter. This updated parameter provides essential recommendations pertaining to clinical history, physical examination, and patch testing evaluation of patients suspected of allergic contact dermatitis. In addition to providing guidance for performing and interpreting closed patch testing, the updated parameter provides concrete recommendations for assessing metal hypersensitivity in patients receiving prosthetic devices, for evaluating workers with occupational contact dermatitis, and also for addressing allergic contact dermatitis in children. Finally, the document provides practical recommendations useful for educating patients regarding avoidance of exposure to known contact sensitizers in the home and at work. The Contact Dermatitis Parameter is designed as a practical, evidence-based clinical tool to be used by allergists and dermatologists who routinely are called upon to evaluate patients with skin disorders.

Wound dressings, does it matter and why?

Compression therapy and treating venous insufficiency is the standard of care for venous leg ulcers. The need for debridement on healing venous leg ulcers is still debated. Dressings are often used under compression bandages to promote faster healing and prevent adherence of the bandage to the ulcer. A wide range of dressings is available, including modern dressings with different kinds of biological activity. Microbial burden is believed to underlie delayed healing, but the exact role of microbiofilm in wound healing is uncertain. Before choosing a specific wound dressing, four main functions should be considered: (1) cleaning, (2) absorbing, (3) regulating or (4) the necessity of adding medication. There is no clear evidence to support the use of one dressing over another, as demonstrated by many Cochrane review studies. In addition, the prescriber should enquire about contact allergies that may also develop during wound treatment. It is shown that early intervention and early investment may reduce the cost of treatment. The choice of wound dressings should be guided by cost, ease of application and patient and physician preference and be part of the complete strategy. The role of the medical specialist is evident. Wound dressings matter as part of the optimal treatment in VLU patients.

Contact dermatitis: a practice parameter-update 2015

This parameter was developed by the Joint Task Force on Practice Parameters, which represents the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Contact Dermatitis: A Practice Parameter-Update 2015." This is a complete and comprehensive document at the current time. The medical environment is changing and not all recommendations will be appropriate or applicable to all patients. Because this document incorporated the efforts of many participants, no single individual, including members serving on the Joint Task Force, are authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information or interpretation of this practice parameter by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by the pharmaceutical industry in drug development or promotion. Previously published practice parameters of the Joint Task Force on Practice Parameters for Allergy & Immunology are available at http://www.JCAAI.org or http://www.allergyparameters.org.

Contact sensitisation in patients with chronic leg ulcers

The aim of our study is to identify the allergens in patients with leg ulcers who have contact dermatitis surrounding the skin of the ulcer and compare them with a control group consisting of patients with lower extremity contact dermatitis. A total of 40 patients with chronic leg ulcers (CLU) and contact dermatitis around the skin of ulcer were included in the study. As a control group, 20 patients with contact dermatitis of lower extremity without leg ulcers were included. The patient and control groups were patch tested with 37 allergens of the European Standard Series. Of the 40 patients, 31 (77·5%) had positivity to one or more allergens, and 10 (50%) of the control group patients had positivity to one or more allergens. The number of patients who had positivity to at least one allergen was significantly higher in the patient group (P < 0·05). Positivity to the balsam of Peru and benzocaine was significantly higher in the patient group than that in the control group (P < 0·05). Contact sensitisation to benzocaine and balsam of Peru was found to be associated with the presence of CLU. The efficacy of therapy in patients with leg ulcers might be increased by avoiding these allergens.

Risk factors of polysensitization to contact allergens

BACKGROUND

'Polysensitization' (PS) is usually defined as contact sensitization to three or more unrelated haptens of the baseline patch test series. Despite PS being an important clinical phenotype indicating increased susceptibility to contact allergy, statistical approaches to analyse PS have hitherto been preliminary.

OBJECTIVES

To apply an appropriate regression model for count data, namely, negative binomial hurdle regression, to a large set of clinical patch test data with the aim of estimating PS risk in more detail than previously achieved.

METHODS

The detailed information provided by the hurdle model includes a separate estimation of an 'increment factor' quantifying the likelihood of further positive reactions, i.e. PS. Clinical data of 126 878 patients patch tested by departments comprising the IVDK (Information Network of Departments of Dermatology) network (www.ivdk.org) between 1995 and 2010 were included.

RESULTS

Regarding anatomical sites as exposure (surrogate), the axillae and the feet were found to be strong PS risk factors. Moreover, age was a strong PS risk factor, and less so, female sex. In comparison, atopic eczema and occupational dermatitis were less important risk factors. Single allergens contributed to PS to a varying extent.

CONCLUSIONS

The data presented point to some, very likely exposure-related, risk factors which need to be considered in future PS research, e.g. addressing the genetic basis for PS.