Positive Patch Test Reactions Research Articles

Contact allergy in children with atopic dermatitis: a systematic review.

The importance of contact allergy in children with atopic dermatitis is frequently debated. Previously, patients with atopic dermatitis were believed to have a reduced ability to produce a type IV immunological response. However, this belief has been challenged and authors have highlighted the risk of underestimating and overlooking allergic contact dermatitis in children with atopic dermatitis. Several studies have been published aiming to shed light on this important question but results are contradictory. To provide an overview of the existing knowledge, we systematically reviewed studies that report frequencies of positive patch test reactions in children with atopic dermatitis. We identified 436 manuscripts of which 31 met the inclusion criteria. Although the literature is conflicting, it is evident that contact allergy is a common problem in children with atopic dermatitis.

Patch testing in patients with suspected cosmetic dermatitis: A retrospective study.

Growing use of cosmetics has led to an increase in the incidence of allergic contact dermatitis (ACD) to cosmetics. Patch testing helps to confirm allergy to cosmetics and pinpoint the exact offending allergens. The study aimed to find the frequency of positive patch test reactions in cases with suspected ACD to cosmetics, and the common allergens responsible for it. This is a retrospective record-based study of 58 patients, with suspected ACD to cosmetics, who had undergone patch testing with Indian standard series and Indian cosmetic and fragrance series from January 2013 to December 2015. The majority of patients (60.34%) belonged to the age group of 20-40 years. The most common site of involvement was face (94.8%) followed by neck (22.4%). The most commonly implicated cosmetics in history were soaps (53.4%), and face creams (24.1%). The most common allergens detected on patch testing were cetrimide (20.7%) and thimerosal (15.5%) followed by paraphenylenediamine (6.9%), and fragrance mix (5.2). Positive allergic reactions were obtained in 2.12% of the patches. Most common cosmetic products implicated for causing ACD were face creams, soaps, and hair dyes. The principal culprit allergens were cetrimide and thimerosal.

Role of footwear allergens in juvenile plantar dermatosis

<p class="abstract"><strong>Background:</strong> Juvenile plantar dermatosis (JPD) is characterized by shiny dry fissured dermatitis of the plantar surface of the foot, affecting children aged 3-14years. The most accepted theory is that JPD is a frictional contact dermatitis of the forefoot in which atopics are more prone to develop. Allergic contact dermatitis remains a close differential diagnosis; it can aggravate the predisposing JPD. In this background we carried out a study among children aged fourteen years and below with clinically diagnosed JPD to know the age and sex profile, aggravating factors and clinical features in this part of the country<span lang="EN-IN">.</span></p><p class="abstract"><strong>Methods:</strong> All children aged 14 years and below with JPD attending our outpatient department from November 2006 to November 2007 were included in this study. Using a preset proforma, data regarding age and sex, information on any relation to footwear, past history of allergic disorders in person or family members was collected. All the 40 patients were patch tested using the footwear allergen series in petrolatum base. Patch test unit was removed after 48hours and the results were interpreted using criteria laid down by International Contact Dermatitis Group (ICDRG). The data was analyzed and made an attempt to understand the role of footwear allergy in JPD.</p><p class="abstract"><strong>Results:</strong> 22 girls and 18 boys attended our OPD with JPD between the age group of 4-14 years. 52.5% were using footwear made of plastic; 25%used leather; 12.5% rubber footwear. Patients presented with erythema and glazed appearance of foot along with fissuring. The areas of involvement were distal soles and toes in 70%, distal sole alone in 7.5% and distal sole and dorsum of toes in 22.5% of patients. Personal history of atopy was documented in 15% of patients and family history of atopy was present in 20% of cases. 20% of patients complained of exacerbation with footwear. Of the 40 patients who underwent patch testing, 10% only showed <span lang="EN-IN">positive patch test reaction mainly to potassium dichromate (5%). </span></p><p class="abstract"><strong>Conclusions:</strong> JPD is not an uncommon disease and it predominantly affects school going children. Seasonal variation was associated with aggravation of disease. Specific footwear was identified to cause flare ups in a significant percentage of study population (20%) and this was proven by patch test results in half of them. Though nearly one fifth of the affected had an atopic diathesis in person or family, the present data suggests that JPD is not exclusive to atopics. A large sized study is required to <span lang="EN-IN">evaluate the role of footwear in JPD.</span></p>

Evaluation of canine adverse food reactions by patch testing with single proteins, single carbohydrates and commercial foods.

Adverse food reaction (AFR) is an important differential diagnosis for the pruritic dog. It is usually diagnosed by feeding an elimination diet with a novel protein and carbohydrate source for eight weeks followed by subsequent food provocation. A previous study demonstrated that patch testing dogs with foods had a high sensitivity and negative predictability for selection of elimination diet ingredients. The aim of this study was to investigate patch testing with proteins, carbohydrates and dry commercial dog food in dogs to determine whether there was value in patch testing to aid the diagnosis of canine adverse food reaction. Twenty five privately owned dogs, with confirmed AFR, underwent provocation trials with selected food antigens and patch testing. For proteins, carbohydrates and dry dog food the sensitivity of patch testing was 100%, 70% and 22.2%, respectively; the negative predictive values of patch testing were 100%, 79% and 72%. The positive predictive values of patch testing for proteins and carbohydrates were 75% and 74%, respectively. This study confirmed that patch testing may be useful for the selection of a suitable protein source for an elimination diet in dogs with suspected AFR, but not as a diagnostic tool for canine AFR. Results for proteins are more reliable than for carbohydrates and the majority of positive patch test reactions were observed with raw protein. Patch testing with commercial dog food does not seem to be useful.

A multi-institutional joint study of contact dermatitis related to hair colouring and perming agents in Japan.

In Japan, allergic contact dermatitis caused by hair colouring agents is a considerable problem for those occupationally exposed and also for consumers. Over the last 20 years, p-phenylenediamine (PPD) has been a common allergen, with ∼7% positive patch test reactions. To investigate which ingredients caused allergic contact dermatitis related to hair dye and perming solutions in Japan, to assess whether PPD is suitable for screening for hair dye allergy, and to propose allergens for a Japanese hairdresser series. We selected 19 hair cosmetic allergens, including PPD, Bandrowski's base, cysteamine HCl, and ammonium thioglycolate. Altogether 203 patients (26 males and 177 females) with suspected contact allergy to hair colouring or perming solutions at 14 hospitals in Japan were included. The highest prevalence of positive reactions (35.1%) was for PPD. p-Methylaminophenol and o-aminophenol were often positive, both in the PPD-positive and in the PPD-negative patients. Moreover, cysteamine HCl often yielded positive test reactions. PPD is insufficient to diagnose contact allergy caused by to hair dyes. We recommend 13 allergens to be included in a Japanese hairdresser series.

Effect of allergens and irritants on levels of natural moisturizing factor and corneocyte morphology.

SummaryBackgroundThe irritant sodium lauryl sulfate (SLS) is known to cause a decrease in the stratum corneum level of natural moisturizing factor (NMF), which in itself is associated with changes in corneocyte surface topography.ObjectiveTo explore this phenomenon in allergic contact dermatitis.MethodsPatch testing was performed on patients with previously positive patch test reactions to potassium dichromate (Cr), nickel sulfate (Ni), methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI), or p‐phenylenediamine. Moreover, a control (pet.) patch and an irritant (SLS) patch were applied. After 3 days, the stratum corneum from tested sites was collected, and NMF levels and corneocyte morphology, expressed as the amount of circular nanosize objects, quantified according to the Dermal Texture Index (DTI), were determined.ResultsAmong allergens, only MCI/MI reduced NMF levels significantly, as did SLS. Furthermore, only MCI/MI caused remarkable changes at the microscopic level; the corneocytes were hexagonal‐shaped with pronounced cell borders and a smoother surface. The DTI was increased after SLS exposure but not after allergen exposure.Conclusions MCI/MI significantly decreased NMF levels, similarly to SLS. The altered corneocyte morphology suggests that skin barrier damage plays a role in the pathogenesis of MCI/MI contact allergy. The DTI seems to differentiate reactions to SLS from those to the allergens tested, as SLS was the only agent that caused a DTI increase.

Experimental patch testing with chromium-coated materials.

Chromium coatings on metal alloys can be decorative, and prevent corrosion and metal ion release. We recently showed that handling of a chromium-containing disc resulted in chromium deposition on the skin. To examine patch test reactivity to chromium-coated discs. We included 15 patients: 10 chromium-allergic patients, and 5 patients without chromium allergy. All were patch tested with potassium dichromate, cobalt chloride, nickel sulfate, and nine different metallic discs. The chromium-allergic patients were also patch tested with serial dilutions of potassium dichromate. Positive/weaker reactions were observed to disc B (1 of 10), disc C (1 of 10), and disc D, disc E, and disc I (4 of 10 each). As no controls reacted to any of the discs, the weak reactions indicate allergic reactions. Positive patch test reactions to 1770 ppm chromium(VI) in the serial dilutions of potassium dichromate were observed in 7 of 10 patients. When the case group was narrowed down to include only the patients with a current positive patch test reaction to potassium dichromate, elicitation of dermatitis by both chromium(III) and chromium(VI) discs was observed in 4 of 7 of patients. Many of the patients reacted to both chromium(III) and chromium(VI) surfaces. Our results indicate that both chromium(VI) and chromium(III) pose a risk to chromium-allergic patients.

Patch testing and cross sensitivity study of adverse cutaneous drug reactions due to anticonvulsants: A preliminary report.

AIMTo evaluate the utility of patch test and cross-sensitivity patterns in patients with adverse cutaneous drug reactions (ACDR) from common anticonvulsants.METHODSTwenty-four (M:F = 13:11) patients aged 18-75 years with ACDR from anticonvulsants were patch tested 3-27 mo after complete recovery using carbamazepine, phenytoin, phenobarbitone, lamotrigine, and sodium valproate in 10%, 20% and 30% conc. in pet. after informed consent. Positive reactions persisting on D3 and D4 were considered significant.RESULTSClinical patterns were exanthematous drug rash with or without systemic involvement (DRESS) in 18 (75%), Stevens-Johnsons syndrome/toxic epidermal necrolysis (SJS/TEN) overlap and TEN in 2 (8.3%) patients each, SJS and lichenoid drug eruption in 1 (4.2%) patient each, respectively. The implicated drugs were phenytoin in 14 (58.3%), carbamazepine in 9 (37.5%), phenobarbitone in 2 (8.3%), and lamotrigine in 1 (4.7%) patients, respectively. Twelve (50%) patients elicited positive reactions to implicated drugs; carbamazepine in 6 (50%), phenytoin alone in 4 (33.3%), phenobarbitone alone in 1 (8.3%), and both phenytoin and phenobarbitone in 1 (8.33%) patients, respectively. Cross-reactions occurred in 11 (92%) patients. Six patients with carbamazepine positive patch test reaction showed cross sensitivity with phenobarbitone, sodium valproate and/or lamotrigine. Three (75%) patients among positive phenytoin patch test reactions had cross reactions with phenobarbitone, lamotrigine, and/or valproate.CONCLUSIONCarbamazepine remains the commonest anticonvulsant causing ACDRs and cross-reactions with other anticonvulsants are possible. Drug patch testing appears useful in DRESS for drug imputability and cross-reactions established clinically.

Allergic contact dermatitis pattern in Kuwait: nickel leads the pack. In-depth analysis of nickel allergy based on the results from a large prospective patch test series report.

IntroductionContact dermatitis is a relatively common dermatosis reported among several population groups from all around the globe. However, the data from Kuwait is unavailable. Patch tests are essential for the diagnosis of contact sensitization.AimTo determine a relative frequency and pattern of sensitizers to different allergens in patients of suspected contact dermatitis in Kuwait and, also to study the role of the commonest sensitizer in detail.Material and methodsPatch tests were performed in 2461 consecutive patients with a clinical diagnosis of contact dermatitis seen at our hospital between September 1, 2014 and August 31, 2015. Out of the total of 1381 (56.1%) patients with positive patch test results to at least one allergen, 546 (22.2%) patients with a single positive reaction to nickel only (single largest sensitizer) were selected as the study population for further detailed analysis.ResultsAt least one positive patch test reaction was found in 1381 (56.12%) patients. Nickel was found to be the most common sensitizer seen in 546 (40%) patients. The mean age was 37.3 ±13.8 years and the mean duration of disease was 27.3 ±13.8 months. Most (387/546) patients sensitized were females. The forearms/hands and wrists were the most prevalent sites (52.56% of the participants). In 58.91% of women, dermatitis was more often confined to other sites, mostly ears and the neck due to earrings and necklaces. Just more than half of the number (51.09%) of nickel allergic patients were found in the age group of 15–25 years. Hairdressers/beauticians were the most affected group followed by house workers (housewives, cleaners, housekeepers).ConclusionsNickel is the single most common sensitizer found in our patients, and female sex, young age, occupation with long hours of contact to nickel are high risk factors. We recommend that a directive, which limits the release of nickel from products with extended skin contact, be approved in Kuwait.

Patch Testing in Patients with Suspected Footwear Dermatitis: A Retrospective Study.

Background:Footwear dermatitis represents a common but often undiagnosed or misdiagnosed condition. Patch testing aids in its confirmation and identification of the offending allergen.Aims:This study aimed to find the frequency of positive patch test reactions in cases with suspected allergic contact dermatitis (ACD) to footwear, as well as the common responsible allergens.Materials and Methods:This is a retrospective record based study of 37 patients, with suspected ACD to footwear, who underwent patch testing with Indian standard series and Indian footwear series from July 2012 to July 2015.Results:The majority of patients (45.94%) belonged to the age group of 20–40 years. Dorsal aspects of feet (81.08%) and soles (18.92%) were the common sites involved. Patch test was positive in 18.92% patients. The most common causative allergens were hydroquinone monobenzylether (8.11%) and 4-aminoazobenzene (5.41%).Conclusion:Common chemicals implicated in ACD were rubber, rubber additives, and dyes. The principal culprit allergens were hydroquinone monobenzylether and 4-aminoazobenzene.

Para-phenylenediamine allergy: current perspectives on diagnosis and management.

Para-phenylenediamine (PPD) is the commonest and most well-known component of hair dyes. Oxidative hair dyes and dark henna temporary tattoos contain PPD. Individuals may be sensitized to PPD by temporary henna tattooing in addition to dyeing their hair. PPD allergy can cause severe reactions and may result in complications. In recent years, frequency of positive patch test reactions to PPD has been increasing. Cross-sensitization to other contact allergens may occur, in particular to other hair dye components. Hairdressers are at a high risk for PPD allergy and require counseling regarding techniques to minimize exposure and protective measures while handling hair dye. We focus this review on the current perspectives of diagnosis and management of PPD allergy.

Wet Wipe Allergens: Retrospective Analysis From the North American Contact Dermatitis Group 2011-2014.

Although there are several case reports of wet wipe-associated contact dermatitis, the prevalence of wipes as a source of allergic contact dermatitis in larger populations and the responsible allergens are largely unknown. The aim of the study was to determine the prevalence of wet wipes as a source of contact allergy and the most commonly associated allergens in a North American tertiary referral patch test population. Data collected from 2011 to 2014 by the North American Contact Dermatitis Group was used to conduct a retrospective cross-sectional analysis of patient demographics and patch test results associated with the triple-digit source code for "wet wipe." Of the 9037 patients patch tested during the study period, 79 (0.9%) had a positive patch test reaction to an allergen identified with a wet wipe source. The most commonly associated allergens were preservatives, including the following: methylisothiazolinone (MI) (59.0%), methylchloroisothiazolinone (MCI)/MI (35.6%), bronopol (2-bromo-2-nitropropane-1,3-diol) (27.4%), and iodopropynyl butylcarbamate (12.3%). Fragrance (combined) represented 12.3%. Anal/genital dermatitis was 15 times more likely (P < 0.0001) in those with wet wipe allergy. More than 92% of patients with wipe-associated contact allergy had their contact allergens detected by the North American Contact Dermatitis Group screening series. Wet wipes are an important source of contact allergy. Preservatives are the main allergens, especially isothiazolinones.

Is there a role of food additives in recurrent aphthous stomatitis? A prospective study with patch testing.

Recurrent aphthous stomatitis (RAS) is a common disease of the oral mucosa with an unknown etiology. This study aimed to determine if food additives play a role in the etiology of RAS as well as to determine if patch testing can be used to detect which allergens cause RAS. This prospective study included 24 patients with RAS and 22 healthy controls. All the participants underwent patch testing for 23 food additives. In total, 21 (87.5%) RAS patients and 3 (13.6%) controls had positive patch test reactions to ≥1 allergens; the difference in the patch test positivity rate between groups was significant (P<0.05). The most common allergen that elicited positive patch test results in the patient group was cochineal red (n=15 [62.5%]), followed by azorubine (n=11 [45.8%]) and amaranth (n=6 [25%]). The present findings show that food additives might play a role in the etiology of RAS and that patch testing could be a method for determining the etiology of RAS.

The epidemic of methylisothiazolinone: a European prospective study.

The use of methylisothiazolinone (MI) in cosmetic products has caused an unprecedented epidemic of MI contact allergy. Current data concerning exposures at a European level are required. To describe demographics and MI exposures for European patients with MI contact allergy. Eleven European dermatology departments from eight European countries prospectively collected data between 1 May and 31 October 2015 among consecutive patients who had positive patch test reactions to MI (2000 ppm aq.). A total of 6.0% (205/3434; range 2.6-13.0%) of patients had positive patch test reactions to MI. Dermatitis most frequently affected the hands (43.4%), face (32.7%), arms (14.6%), and eyelids (11.7%); 12.7% had widespread dermatitis. For 72.7% (149/205), MI contact allergy was currently relevant mainly because of exposure to cosmetic products (83.2%; 124/149). Of these 124 patients, 19.5% were exposed to leave-on and rinse-off cosmetic products, 24.8% only to leave-on cosmetic products and 38.9% only to rinse-off cosmetic products containing MI or methylchloroisothiazolinone/MI. The majority of these (79%) noted onset of their dermatitis between 2013 and 2015. Fifteen patients (7.3%) had previously experienced allergic reactions when they were in newly painted rooms. Clinically relevant MI contact allergy remains prevalent across European countries, mainly because of exposure to rinse-off and leave-on cosmetic products.

Long-term reproducibility of positive patch test reactions in patients with non-immediate cutaneous adverse drug reactions to antibiotics.

As in contact allergy, T cell-mediated hypersensitivity in non-immediate (NI) cutaneous adverse drug reactions (CADRs) to antibiotics is considered to be lifelong, but, in this setting, patch tests have rarely been repeated after long time intervals. To evaluate the long-term reproducibility of positive patch test reactions to antibiotics in patients with NI CADRs. Fifty-six patients with NI CADRs to antibiotics who had relevant positive reactions during patch testing were invited to repeat patch tests with a similar antibiotic series 2-15 years thereafter. Twenty patients were included (9 males and 11 females; mean age 54.6 years): 18 with maculopapular exanthema, 1 with drug hypersensitivity syndrome, and 1 with acute generalized exanthematous pustulosis. Results were reproducible in 17 of 20 patients after a mean interval of 6.0 years (range 2-14.7 years). Concerning β-lactams, 7 of 8 patients remained positive for aminopenicillins, 4 of 4 for isoxazolyl penicillins, and 1 for cefoxitin. Patch test results were also reproducible for clindamycin in 5 of 7 patients, for vancomycin in 1 patient, and for spiramycin in 1 patient. Reproducibility was not affected by the time interval between tests, sex, or age at testing. In the context of NI CADRs, we showed high reproducibility of positive patch test reactions to various antibiotics, even after several years.

Contact sensitization to limonene and linalool hydroperoxides in Spain: a GEIDAC* prospective study.

Limonene and linalool are common fragrance terpenes widely used in cosmetic, household and hygiene products. Their primary oxidation products formed after air exposure, the hydroperoxides, have been recognized as important contact haptens. To investigate the prevalence of contact allergy to hydroperoxides of limonene (Lim-OOHs) and hydroperoxides of linalool (Lin-OOHs) in Spain, and to define the optimal concentration for screening in consecutive patients. Three different concentrations of Lim-OOHs (0.1%, 0.2% and 0.3% pet.) and Lin-OOHs (0.25%, 0.5% and 1.0% pet.) were simultaneously tested in 3639 consecutive patients at 22 departments of dermatology in Spain. Lim-OOHs at 0.1%, 0.2% and 0.3% yielded positive patch test reactions in 1.4%, 3.4% and 5.1% of the tested patients, respectively; and Lin-OOHs at 0.25%, 0.5% and 1.0% yielded positive reactions in 1.3%, 2.9% and 4.9% of the tested patients, respectively. Few irritant (1.5-1.9%) and doubtful reactions (0.4-0.5%) to both terpene hydroperoxides were registered at the highest concentrations tested. Lim-OOHs and Lin-OOHs can be considered as common causes of contact allergy, and their inclusion in an extended baseline patch test series therefore seems to be appropriate. The patch test preparations of Lim-OOHs 0.3% pet. and Lin-OOHs 1.0% pet. are useful tools for screening of contact sensitization.

Environmental exogenous factors and facial dermatitis: A case control study

Abstract Background/objective Facial dermatitis is common and the roles different exogenous factors play between facial and nonfacial dermatitis is unknown. The study aim was to investigate the etiology and self-reported exogenous aggravation factors in facial dermatitis. Methods There were 89 facial dermatitis patients patch tested in a tertiary hospital during a 1-year period, and 112 patients with nonfacial dermatitis tested in the same period who served as a control. Association of exogenous factors was investigated by multivariate analyses. Results Of the cases of facial dermatitis, 30.3% were confirmed allergic contact dermatitis, which was higher than that (23.2%) in controls. Cosmetic allergy was much more common in facial than nonfacial allergic contact dermatitis (96.3% vs. 19.2%); 51.9% of facial allergic contact dermatitis cases were caused by facial creams; 6.7% of facial dermatitis were irritant contact dermatitis, compared with 2.7% for controls; 9.0% of cases were seasonal facial dermatitis. The positive patch test reactions to at least one standard allergen were 65.2% in facial dermatitis and 58.0% in controls. Self-reported exogenous aggravation factors in facial dermatitis were spicy food ingestion (24.7%), low moisture (22.5%), sunlight (19.1%), alcohol ingestion (15.7%), seafood ingestion (14.6%), beef or lamb ingestion (12.4%), and high humidity (5.6%). Multivariate logistic regression analysis adjusting for sex, age, disease duration, atopic diathesis, and contact allergy showed that more patients reported aggravation by sunlight exposure ( p = 0.008), ingestion of spicy food ( p = 0.025), or alcohol ( p = 0.044). Conclusions Contact factors play an important role in facial dermatitis. Aggravation by sunlight exposure, ingestion of spicy food, or alcohol are more reported in facial dermatitis compared with nonfacial dermatitis.

Clearance of Erythroderma in a Patient on Apremilast and Positive Patch Test Reactions While on Treatment.

Clearance of Erythroderma in a Patient on Apremilast and Positive Patch Test Reactions While on Treatment.

The Association of Race/Ethnicity and Patch Test Results: North American Contact Dermatitis Group, 1998-2006.

The North American Contact Dermatitis Group patch tests patients with suspected allergic contact dermatitis (ACD) to a broad series of screening allergens and publishes periodic reports. We have previously reported on the association of race and ethnicity with the rates of positive responses to standard patch test allergens. This report extends those observations. The aim of the study was to report the North American Contact Dermatitis Group patch testing results from January 1, 1998, to December 31, 2006, comparing the frequency of positive reactions between white and black subjects. Standardized patch testing with 45 allergens was used at 13 centers in North America. χ analysis of results in black subjects as compared with whites was examined. A total of 19,457 patients were tested; 92.9% (17,803) were white and 7.1% (1,360) were black. The final diagnoses of ACD (whites, 45.9%; blacks, 43.6%) and irritant contact dermatitis (13.0%/13.3%) were similar in the 2 groups. The diagnosis of atopic dermatitis was less common in the white patients (8.9%) as compared with the black patients (13.3%). Positive patch test reactions rates were similar for most allergens. However, statistically, blacks reacted more frequently to p-phenylenediamine (7.0% vs 4.4%, P < 0.001), bacitracin (11.6% vs 8.3%, P = 0.0004), as well as specific rubber accelerators mercaptobenzothiazole (2.7% vs 1.8%), thiuram (6.2% vs 4.3%), and mercapto mix (1.9% vs 0.8%, P < 0.001). Whites had an increase in positive reactions to fragrances (12.12% vs 6.77%, P < 0.0001), formaldehyde (9.25% vs 5.45%, P < 0.0001), and some formaldehyde releaser preservatives used in personal care products and textile resins (9.80% vs 6.18%, P < 0.0001). There were statistically different rates of positive patch test reactions to specific allergens between black and white patients suspected of having ACD. The etiology of these differences is unclear but probably relates to culturally determined exposure patterns rather than genetic differences.

Contact dermatitis in patients with chronic leg ulcers: a common and neglected problem: a review 2000-2015.

Contact allergies can occur frequently in patients with chronic leg ulcers (CLUs), even in those with a short duration of ulcerative disease. The wide spectrum of therapeutic products promotes development of the delayed type of hypersensitivity and continuous changes in the allergens pattern, which make the diagnosis and treatment extremely difficult in many cases. A prompt diagnosis and treatment of allergic contact dermatitis (ACD) in patients suffering from CLUs is very important for a best clinical outcome of these two common diseases. Thus, this review aims to highlight a common, challenging and often neglected problem. The search included all studies published between 2000 and September 2015. Keyword used were: 'allergic contact dermatitis leg ulcer', 'contact dermatitis leg ulcers' 'contact dermatitis wound care' 'contact dermatitis non-healing wounds' 'contact sensitisation non-healing wounds'. Contact allergy and polysensitisation are very frequent in patients suffering from CLUs. Although it is believed modern dressings have a lower potential for inducing cutaneous sensitisation, positive patch test reactions to modern dressing are becoming common: hydrogels, followed by hydrocolloid and the ionic silver-containing wound dressing seem to be the principal causes of ACD. This review wanted to highlighted ACD in CLUs as a common and neglected disease whose economic and social burden has not previously been estimated, giving new insights for clinical and therapeutic management.