The CXCR3 activating chemokines IP-10, Mig, and IP-9 are expressed in allergic but not in irritant patch test reactions.

Differentiation between allergic and irritant contact dermatitis reactions is difficult, as both inflammatory diseases are clinically, histologically, and immunohistologically very similar. Previous studies in mice revealed that the chemokine IP-10 is exclusively expressed in allergic contact dermatitis reactions. In the present study, we investigated whether the mRNA expression of IP-10 and the related CXCR3 activating chemokines, Mig and IP-9 are also differentially expressed in human allergic contact dermatitis and irritant contact dermatitis reactions. Skin biopsies from allergic (13 cases) and sodium lauryl sulfate-induced irritant patch test reactions (13 cases), obtained 1-72 h after patch testing, were studied by means of an in situ hybridization technique. Results of chemokine mRNA expression were correlated with clinical scoring, histology, and immunohistochemical data including the proportion of inflammatory cells expressing CXCR3, the receptor for IP-10, Mig, and IP-9, and ICAM-1 and HLA-DR expression on keratinocytes. IP-10, Mig, and IP-9 mRNA were detected in seven of nine allergic contact dermatitis reactions after 24-72 h, but not in sodium lauryl sulfate-induced irritant contact dermatitis reactions. ICAM-1 expression by keratinocytes was only found in allergic contact dermatitis reactions and correlated with chemokine expression. Moreover, up to 50% of the infiltrating cells in allergic contact dermatitis expressed CXCR3, in contrast to only 20% in irritant contact dermatitis reactions. In conclusion, we have demonstrated differences in chemokine expression between allergic contact dermatitis and irritant contact dermatitis reactions, which might reflect different regulatory mechanisms operating in these diseases and may be an important clue for differentiation between allergic contact dermatitis and irritant contact dermatitis reactions.     

Patch testing with methyldibromo glutaronitrile, a multicentre study within the EECDRG

Contact allergy to and allergic contact dermatitis from methyldibromo glutaronitrile (MDBGN) have frequently been reported. As there has been no agreement on which MDBGN test preparation to use, a study was initiated to help determine the optimal patch test preparation for MDBGN. 2661 consecutively patch tested patients at 11 test clinics representing 9 European countries participated. Petrolatum preparations with MDBGN at 1.0%, 0.5%, 0.3% and 0.1% were inserted in the standard series. Contact allergy rates were noted in the range 4.4-1.1% following decreasing test concentrations. Reactions not fulfilling all criteria to be classified as allergic reactions could represent either weak allergic or irritant reactions, and such reactions were noted in the range 8.2-0.5% with decreasing concentrations. A significant number of these reactions represented weak allergic reactions, as allergic reactions were obtained to higher patch test concentrations in the same individual. Morphologically irritant reactions were noted only for the highest test concentrations. In summary, the contact allergy rates and frequencies of doubtful and irritant reactions vary with the patch test concentration. The final decision on patch test concentration for MDBGN should not only rely on these factors but also include information on patch test concentrations required to diagnose individual cases with allergic contact dermatitis from MDBGN as well as results of repeated open application tests.     

Occupational contact allergy to cocamidopropyl betaine and its impurities

Background. Contact allergy to cocamidopropyl betaine has been attributed to its impurities dimethylaminopropylamine and cocamidopropyl dimethylamine. Objectives. To describe patients with positive patch test reactions to cocamidopropyl betaine‐related compounds in an occupational dermatology clinic. Methods. We reviewed the 2002–2009 patch test records at the Finnish Institute of Occupational Health for allergic reactions to cocamidopropyl betaine, dimethylaminopropylamine, cocamidopropyl dimethylamine, and oleamidopropyl dimethylamine. Results. Irritant reactions to at least one of the test substances were seen in 39% of the 1092 patients tested. Fifteen (1.3%) patients showed allergic reactions: 13 to cocamidopropyl dimethylamine, 11 to dimethylaminopropylamine, 8 to oleamidopropyl dimethylamine, and 2 to cocamidopropyl betaine. Concomitant reactions to cocamidopropyl dimethylamine, dimethylaminopropylamine and oleamidopropyl dimethylamine were common. Ten of the 15 patients were diagnosed with occupational allergic contact dermatitis caused by cocamidopropyl betaine‐related compounds. The sources of occupational exposure included hair care products, hair colours, perm wave solutions, and liquid soaps. Multiple contact allergies and exposure to several irritant factors were common, and all patients had hand eczema. Conclusions. Patch test reactions to cocamidopropyl betaine‐related compounds are difficult to interpret, owing to extremely common irritant reactions. Cocamidopropyl betaine itself is probably not an allergen. Occupational allergic contact dermatitis caused by cocamidopropyl betaine‐related compounds is relatively rare and, unlike non‐occupational cocamidopropyl betaine‐related allergy, typically manifests as hand dermatitis.     

Occupational contact allergy to glyoxal

Glyoxal is a dialdehyde that is used as a disinfectant in health care and dentistry work. Allergic contact dermatitis from glyoxal has been described in these occupations. We analysed our patient data from 1998 to 2004 for allergic reactions to glyoxal. 20 patients had allergic reactions to glyoxal on patch testing. 5 of these patients worked in dentistry and 4 of them had present exposure to glyoxal. 9 patients were machinists without obvious exposure to glyoxal. A grinder with work-related facial dermatitis is described in detail. The chemical analysis of air samples from his workplace revealed 9.4-21 microg/m3 glyoxal. Glyoxal was also present in the used metal-working fluid, and apparently it had been formed during grinding. The remaining 6 patients worked in miscellaneous occupations and had no present exposure to glyoxal. Glyoxal is irritant on patch testing. Especially, solitary reactions to glyoxal 10% in aq. may be false-positive irritant reactions. 9 (45%) of our patients reacted to formaldehyde or glutaraldehyde. Glyoxal is an important allergen in dentistry and medical care, and we recommend it to be added to the antimicrobial patch test series. It also seems to be a 'hidden' allergen in the metal industry.     

Relationship of occupation to contact dermatitis: Evaluation in patients tested from 1998 to 2000

BACKGROUND: Both irritant and allergic contact dermatitis can be influenced by occupational and nonoccupational environmental exposures. OBJECTIVE: The aim of this study is to compare the occupations and allergens of occupational contact dermatitis cases with nonoccupational contact dermatitis cases. METHODS: Diagnostic patch testing was conducted with the 50 screening allergens of the North American Contact Dermatitis Group and occupational coding by the Surveillance Branch of the National Institute of Occupational Safety and Health. RESULTS: Of the 5,839 patients patch tested for contact dermatitis, 1,097 (19%) were deemed to be occupationally related. Of the occupational cases, 60% were of allergic and 32% were of irritant origin. The hands were the primary body part affected in 64% of allergic occupational cases and 80% of irritant occupational cases. Epoxy resin was the only allergen tested that was associated more with an occupational exposure than nonoccupational exposure. The allergens encountered most frequently in the occupational cases were carba mix, thiuram mix, epoxy resin, formaldehyde, and nickel. The medical field is overrepresented in the data compared with other occupations. CONCLUSIONS: Occupational contact dermatitis frequently was found to be multifactorial and associated with several specific allergens and occupations.     

Allergic contact dermatitis to topical minoxidil solution: etiology and treatment.

After more than a decade of use, topical minoxidil solution has proven to be a safe and effective treatment for androgenetic alopecia. However, some patients present with complaints of pruritus and scaling of the scalp. The most common causes of these symptoms include irritant contact dermatitis, allergic contact dermatitis, or an exacerbation of seborrheic dermatitis. Patients suffering from allergic contact dermatitis may benefit from patch testing to determine the causative allergen. Among the patients we patch tested, propylene glycol was found to be the contactant in a majority of cases, not the minoxidil itself. Many of these patients may be candidates for treatment with alternative formulations using other solvents, such as butylene glycol, polysorbate, or glycerol. Although predictive, patch testing results do not ensure that the compounded preparations will be tolerated. Unfortunately, patients found to be allergic to minoxidil are no longer candidates for topical treatment of their alopecia with any preparations of minoxidil.     

'Irritants' increase the response to an allergen in allergic contact dermatitis

We studied the effect of "irritants" on the response to an allergen in 15 patients. Dilutions of allergens were applied in duplicate, and 24 hours later they were removed and sodium lauryl sulfate (11 subjects) or anthralin (dithranol) (four subjects) was applied for a further 24 hours to one set of patches. Control dilutions of irritants alone were applied. Responses were measured objectively at 72 hours. The response to both allergen and irritant was greater than to either alone. Doses of allergen, which did not produce a response when applied alone, produced a response when an irritant was added. Irritants therefore increase the allergic contact dermatitis response and may explain the presence of contact dermatitis in patients with negative patch tests.     

Case of allergic contact dermatitis due to 1,3‐butylene glycol

1,3‐Butylene glycol (1,3‐BG) is widely used in cosmetics, including low‐irritant skin care products and topical medicaments, as an excellent and low‐irritation humectant. We report a case of allergic contact dermatitis caused by 1,3‐BG. A 28‐year‐old woman suffered from an itchy erythematous eruption on her face. By 2 days of closed patch testing, her own cosmetics and many of the hypo‐irritant skin care products showed positive results. A second patch testing showed positive reaction to 1,3‐BG (1% and 5%). 1,3‐BG was a common component in most of the products that had elicited a positive reaction in the first patch testing. Although allergic contact dermatitis due to 1,3‐BG is not so common, we have to consider 1,3‐BG as a possible contact allergen in the patients presenting with allergic contact dermatitis due to various cosmetics.     

Phenotypic difference between allergic and irritant patch test reactions in man

Cellular responses in allergic and irritant contact dermatitis were analysed in situ using an immunohistochemical double staining technique with the aim of uncovering phenotypical differences of diagnostic importance. Allergic and irritant patch test reactions were elicited in 9 individuals using the Finn chamber technique. Thirty-nine skin biopsies from these reactions and from petrolatum controls were obtained 4 to 20 days after the test applications. Cell infiltrates were present throughout the observation period in both allergic and irritant reactions, but were usually greater in the former. In both types of reaction, anti-Leu 3a reactive cells predominated over anti-Leu 2a reactive cells. HLA-DR expression on keratinocytes was found in 9 of 14 allergic reactions, but not in irritant reactions or control areas. HLA-DQ antigens were not detected on keratinocytes. The presence of HLA-DR antigens on keratinocytes may reflect an immunological response of the allergic reactions, and thus be of diagnostic relevance.     

Contact dermatitis: a common adverse reaction to topical traditional Chinese medicine

Background Over the past decade, there has been an increase in the use of topical traditional Chinese medicine (TTCM). The most common adverse event seen in the use of TTCM is contact dermatitis. This retrospective study was designed to determine the types of commonly used TTCM in Singapore causing contact dermatitis. Methods We retrospectively reviewed the case notes of 10 patients seen at the National Skin Centre over a 4‐month period with a diagnosis of adverse cutaneous reactions to TTCMs. Results A total of 10 patients were diagnosed with contact dermatitis to TTCM at our institution over a 4‐month period. The clinical manifestation ranged from eczematous lesions to urticarial plaques and blisters. Five of these patients were patch‐tested to our standard series, our in‐house TTCM series, as well as to the TTCM they had used. The other five patients declined patch testing. The results of patch testing confirmed the diagnosis of allergic contact dermatitis in three of the tested patients. Negative patch testing results inferred the diagnosis of irritant contact dermatitis to TTCM in the other two patients. Two of the patients with positive patch tests also had a positive reaction to balsam of peru and fragrance mix. The three positive patch tests were all caused by medicated oils. Conclusions These results suggest it is likely that essential oils present as constituents of the medicated oils could be the possible allergen. The study also confirms that contact dermatitis is a common adverse event associated with the use of TTCM.     

Citral a fragrance allergen and irritant

Citral is a well known contact allergen and a contact irritant. Routine patch testing in the past may have been restricted because of possible irritant (IR) patch test responses. 586 consecutive patients, with hand eczema, were patch tested with a selection of fragrances including citral 2% petrolatum and the European standard series. 28 of the patients showed a positive patch test reaction (+ to +++) to citral and 82 at least 1 IR patch test reaction and no positive patch test reaction to citral. A statistically significant association between a positive patch test reaction to citral and positive patch test reactions to other fragrances compared with IR reactions (n = 82) was established. The difference regarding fragrance history found between those with IR and positive reactions to citral was not significant. Citral could be an allergen and/or irritant, worthy of further more extensive studies.     

Dermatitis in hairdressers

Contact dermatitis among hairdressers is common. In The Netherlands, registered sick leave for hand dermatitis among hairdressers rose from 21,050 days in 1986 to 54,293 in 1991. In a survey among 45 hairdressers in 5 different salons, 12 had a history of hand dermatitis and 16 showed moderate to severe hand dermatitis. After extensive investigations, 13 were classified as having allergic contact dermatitis and 3 cumulative irritant contact dermatitis, fn the past 4 years, 103 hairdressers were extensively patch tested and glyceryl thioglycolate (GTG), ammonium persulfate and nickel sulfate were responsible for the majority of positive reactions. Hair dyes and preservatives were responsible for a moderate % of the positive reactions. Positive reactions were also found to cocamidopropyl betaine and sodium coco hydrolyzed animal protein. These 2 allergens show a rather capricious patch test reaction pattern and irritant reactions may easily be confused with allergic. The relevance of positive patch test reactions to these chemicals should always be questioned. Atopy was not a frequent cause of hand dermatitis in this study. Chemicals with a thiol group can be demonstrated with a chemical spot test. With this test, contamination of the hairdressing salon with thioglycolates was demonstrated. It is emphasized that contamination of hairdressing salons with GTG is probably a significant factor in explaining the severe flare-ups in GTG-sensitized hairdressers who no longer use GTG permanent-waving solutions.     

Patch testing in children and adolescents: Five years' experience and follow-up

Background: Allergic contact dermatitis in children is a significant clinical problem. Little information is available concerning the value of patch testing and the outcome in these children.Objective: Our purpose was to assess the value of patch testing in children and the outcome of allergic contact dermatitis in childhood.Methods: Clinical data on 83 children patch tested during a 5-year period were assessed. Clinical follow-up on 68 subjects was performed.Results: Overall, 41 children had one or more allergic reactions (49%). Reactions to metals, topical preparations, and food additives were common. The clinical outcome at 6 months was significantly better for 36 children with a relevant allergen on patch testing than in 32 with no allergen or no relevant allergen (p = 0.006).Conclusion: Patch testing is useful in the management of children suspected of having an allergic contact dermatitis. Patch testing and subsequent allergen avoidance may improve the prognosis in children with a relevant contact allergen. (J Am Acad Dermatol 1997;37:964-8.)     

Retrospective survey of patch testing at department of dermatology and venerology, zagreb university hospital center in zagreb, croatia

Epicutaneous (patch) test is a standard test to confirm contact allergy. During a six-year period (1998-2003), contact allergic dermatitis was diagnosed in 4132 (65%) of 6341 patients using standard patch test with a Croatian series of allergens according to the International Contact Dermatitis Research Group (ICDRG). The most common clinical diagnoses related to contact allergy (male; female) were contact allergic dermatitis (65.4%; 72.2%); atopic dermatitis (15.9%; 11.7%); contact irritant dermatitis (7.0%; 6.6%) and nummular eczematoid dermatitis (4.2%; 2.4%). According to occupation, positive patch test reaction was most commonly observed in workers, whereas 65% of patients showed positive reactions to one or more substances. There was an increased frequency of positive patch test reactions to potassium dichromate, nickel sulfate, thimerosal and neomycine sulfate, along with a significant decrease in the frequency of positive patch test reactions to cobalt chloride, carba mix, wood tars, detergents, parabens mixture, urushiol and rubber mixture. We strongly recommend keeping up-to-date with the epidemiology of contact allergy in Croatia.     

Minimum eliciting patch test concentration of thimerosal

Positive patch test reactions to thimerosal 0.1% pet. (40/690 subjects: 5.8%) were more common in younger age groups, in the allergic contact dermatitis group and in subjects who had used contact lens solutions. In the 40 thimerosal-positive patients, the minimum eliciting quantity of preservative was evaluated using different test concentrations: 0.05% and 0.01% pet. (patch testing) and 1:10,000 in saline (intradermal testing). Cross-reactions between thimerosal and other mercury compounds and sensitivity to thiosalicylic acid were also examined. The results of the investigation demonstrate that many of the reactions to 0.1% thimerosal are probably irritant, because only half the subjects studied had positive patch tests when allergen concentrations 5 to 10x lower than that conventionally used for patch testing, were utilized. In these subjects, the average strength of patch test reactions was higher, intradermal testing was more often positive and cross-reactions between mercurials more frequent. These data indicate that the optimal eliciting patch test concentration for studying thimerosal sensitivity is 0.05% pet.     

Alterations of epidermal lectin binding sites in acute contact dermatitis

We investigated alterations of epidermal lectin binding sites, as well as of pemphigus and bullous pemphigoid antigens, in 28 human patch test reactions, both allergic (nickel, formaldehyde, N,N'-1,3-dimethylbutyl-N'-phenylenediamine) and irritant (sodium lauryl sulfate). The epidermal reactivity to a panel of lectins and human antisera to pemphigus vulgaris and bullous pemphigoid antigens was compared with samples obtained from normal skin and from skin under tape occlusion. We observed selective perturbations of lectin and antibody binding in acute contact dermatitis, whether allergic or irritant. The main findings were a loss of terminal sialic acids and longer bi- and triantennary mannosyl residues as well as a loss of pemphigus vulgaris antigen. The only difference between allergic and irritant patch test reactions was in topography of loss of WGA binding sites: in the former, it was most pronounced in the lower and middle epidermis, whereas in the latter it was seen in the uppermost subcorneal layers. Our findings support a common pathway of cell membrane alterations of keratinocytes in acute contact dermatitis.     

Results of evaluating health care workers with prick and patch testing.

BACKGROUND: Health care workers are exposed to many agents that can cause irritant or allergic contact dermatitis. Recently, much attention has been focused on latex sensitivity, which commonly causes contact urticaria. Most studies have examined the conditions of irritant or allergic contact dermatitis and contact urticaria independently. Therefore, we have little information about the possible occurrence of these conditions in the context of combined assessment including both prick and patch testing. OBJECTIVE: To determine the prevalence of irritant and allergic contact dermatitis and contact urticaria in a group of health care workers presenting with skin problems. METHODS: Retrospective review of health care workers assessed by both prick and patch testing in an occupational health clinic. RESULTS: The diagnoses included 61% with irritant contact dermatitis, 31% with allergic contact dermatitis, and 27% with contact urticaria to latex. Eleven percent had both allergic contact dermatitis related to thiuram and contact urticaria to latex. Ninety five percent were deemed to be work-related. CONCLUSION: Health care workers presenting with skin complaints should be assessed with both prick and patch testing.     

Non-invasive evaluation of the kinetics of allergic and irritant contact dermatitis

Reflectance confocal microscopy (RCM) allows non-invasive visualization of human skin in vivo. It has been used to describe the histopathological features of acute contact dermatitis (CD). This work was designed to investigate the kinetics of both allergic and irritant CD (ACD and ICD) in vivo. Eighteen subjects with a prior diagnosis of ACD were patch tested with the specific allergen sodium lauryl sulfate as an irritant, and appropriate controls. RCM, transepidermal water loss (TEWL), and fluorescence excitation spectroscopy (FES) were performed at several time points within 2 wk after patch removal. After removal of the Finn chambers at 48 h, superficial epidermal changes, primarily involving the stratum corneum, and increased epidermal thickness were mainly present in ICD. ACD, on the other hand, showed microvesicle formation peaking at 96 h following patch removal. Both ACD and ICD showed exocytosis and similar degrees of spongiosis on RCM. TEWL and FES demonstrated a significant difference between ACD and ICD. RCM, TEWL, and FES are valuable non-invasive tools to quantitatively study the kinetics of the pathophysiology of acute CD reactions in vivo and monitor the changes at a cellular level.     

Occupational contact dermatitis in nurses with hand eczema

Occupationally related dermatitis is a common problem in nurses, who are exposed to a wide variety of allergenic and irritant substances. In a group of 44 nurses with hand dermatitis (40 female, 4 male), 18 were thought to have a predominantly allergic contact dermatitis, 15 an irritant dermatitis, 7 other form of eczema, 3 atopic dermatitis and one pompholyx. 10 of the 15 irritant cases were diagnosed as occupational. Of the 18 patients with allergic contact dermatitis, the allergens were thought to be occupationally relevant in 8 cases. In 6 of these 8 the dermatitis was due to natural rubber latex (3) or other rubber chemicals (3). 2 had additional evidence of immediate-type hypersensitivity to natural rubber latex (one was patch test allergic to latex, the other to thiuram mix). Natural rubber latex allergy, both delayed and immediate, is a significant problem, and nurses at risk should be tested for both types of hypersensitivity, as well as being patch tested to standard, rubber and medicaments series.     

Propylene glycol dermatitis: re-evaluation of an old problem

Evaluation of dermatitis associated with propylene glycol application or ingestion remains a challenge. The research dealing with skin reactions to propylene glycol is revisited and new aspects for future research are outlined. Based on literature review and our own observations, we propose classifying skin reactions to propylene glycol into 4 mechanisms: (a) irritant contact dermatitis, (b) allergic contact dermatitis, (c) non-immunologic contact urticaria, and (d) subjective or sensory irritation. This concept allows a partial explanation of effects observed by different authors. Despite attempts to define objective criteria, biologically, histopathologically, or clinically, the distinction between irritant and allergic reactions remains unclear. Furthermore, the irritation threshold of propylene glycol, and likewise the optimal standard concentration in patch tests, is subjudice. Future studies on propylene glycol dermatitis should include repeated patch tests with serial dose dilutions, repeated open application tests/pro vocative use tests, oral challenge tests, and biopsies for a more complete evaluation of mechanisms and clinical significance.