North American Contact Dermatitis Group patch-test results, 1996-1998

Cross-Reactivity Between Propylene Glycol and Butylene Glycol

Background: Propylene glycol (PG) and butylene glycol (BG) are not known to be cross-reactors. However, no large-scale studies have assessed the cross-reactivity rate (CRR) between these 2 structurally and functionally similar compounds. Objectives: The aim of this study was to determine whether PG and BG demonstrate cross-reactivity. Methods: This is a retrospective chart review of 893 patients who underwent patch testing for both PG and BG from 2020 to 2022. The frequencies of positive reactions and concomitant reaction rates were calculated. Results: In our cohort, 53 (5.94%) patients reacted to PG and 13 patients (1.46%) reacted to BG. Of the patients who reacted to PG, 6 reacted to BG representing a CRR of 11.3%, whereas the CRR to PG in BG-allergic patients was 46.2%. Conclusions: For those allergic to BG, PG should be considered a cross-reactor. This relationship is somewhat unidirectional, as patients allergic to PG demonstrated a CRR to BG of only 11.3%, significantly lower than the 46.2% CRR to PG among BG-allergic patients.

The sesquiterpene lactone mix: A review of past, present and future aspects

The sesquiterpene lactones (SLs) are secondary plant metabolites, which are widespread in the Compositae/Asteraceae plant family. The first SLs were detected more than 100 years ago, and allergic contact dermatitis from Compositae has been reported since the beginning of the 1900s, but it was not until the late 1960s and early 1970s that a collaboration between dermatologists, chemists and botanists led to the detection of SLs as the main allergens of Compositae plants. In the 1980s, the SL mix, consisting of equimolar amounts of alantolactone, costunolide and dehydrocostus lactone, was developed as a screening agent for Compositae sensitisation. Today, after inclusion of SL mix in the baseline series, the mean prevalence of reactions in Europe is around 1%, and in North America 0.8%. In countries outside Europe and North America, the prevalence ranges between 0% and 10.7%. The detection rate of SL mix is lower than that of some plant extracts, and ideally, SL mix should be supplemented with a mix of SLs from locally prevalent allergenic plants. The prevalence of positive reactions to SL mix suggests continued baseline testing in most European countries, North America, New Zealand, Australia and probably some Chinese centres.

Patch Testing to Paraphenylenediamine: The North American Contact Dermatitis Group Experience (1994-2018)

Background/Objectives: Paraphenylenediamine (PPD) is an aromatic amine dye that may cause allergic contact dermatitis. This study examines the epidemiology of allergic patch test reactions to PPD. Methods: This retrospective analysis characterizes individuals tested to PPD (1% petrolatum) by the North American Contact Dermatitis Group (1994-2018). Demographics and dermatitis site(s) were compared between PPD-allergic and PPD-negative patients. PPD reactions were analyzed by reaction strength, clinical relevance, occupational relatedness, and source as well as coreactivity with structurally related compounds. Results: Of 54,917 patients tested to PPD, 3095 (5.6%) had an allergic patch test reaction. Compared with PPD-negative patients, PPD-allergic patients had significantly greater odds of age >40 years (odds ratio [OR] 1.55 [95% confidence interval; CI 1.43-1.69]) and female gender (OR 1.52 [95% CI 1.41-1.66]), but lower odds of being White (OR 0.66 [95% CI 0.60-0.71]). The most common primary anatomic sites of dermatitis were face (25.5%), hands (21.9%), and scattered/generalized pattern (15.5%). Over half (55.3%) of PPD reactions were ++ or +++ at the final reading and 60.9% were currently relevant. Common exposure sources included hair dye (73.5%) and clothing/shoes/apparel (3.9%). Occupationally related reactions occurred in 8.3%, most commonly in hairdressers/cosmetologists (72.8%). The most common coreactions were benzocaine (11.3%), N-isopropyl-N'-phenyl-p-phenylenediamine (6.7%), disperse dye mix (6.5%), and black rubber mix (5.1%). Conclusions: The 24-year percentage of allergic reactions to PPD was 5.6%. PPD allergy was associated with female gender and age >40 years. PPD allergic patients were less likely to be White. Allergic reactions were usually clinically relevant and hair dye was the most frequently identified source.

North American Contact Dermatitis Group Patch Test Results: 2019-2020

Background: Patch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD). Objective: This study documents the North American Contact Dermatitis Group (NACDG) patch testing results from January 1, 2019, to December 31, 2020. Methods: At 13 centers in North America, patients were tested in a standardized manner with a screening series of 80 allergens, and, as indicated, supplemental allergens. Results: Overall, 4121 patients were tested; 2871 (69.7%) had at least 1 positive/allergic patch test reaction and 2095 patients (51.2%) had a primary diagnosis of ACD. The most commonly positive allergens were nickel (18.2%), methylisothiazolinone (MI) (13.8%), fragrance mix (FM) I (12.8%), hydroperoxides of linalool (HPL) (11.1%), and benzisothiazolinone (BIT) (10.4%). Compared with that of 2017-2018, prevalence of top 20 allergens statistically increased for FM I, HPL, BIT, propolis, and hydroperoxides of limonene (3.5%). For the first time, MI positivity did not increase between reporting periods. Approximately one-fifth of patients (20.3%) had ≥1 clinically relevant reaction(s) to allergens/substances not on the NACDG series. Conclusions: The epidemic of MI contact allergy in North America may have reached a plateau. Patch testing using a robust screening series, and supplemental allergens as indicated, is necessary for comprehensive evaluation of ACD.

Systematic review on skin adverse effects of important hazardous hair cosmetic ingredients with a focus on hairdressers

BACKGROUND

The burden of occupational hand eczema in hairdressers is high, and (partly strong) allergens abound in the hair cosmetic products they use.

OBJECTIVES

To systematically review published evidence concerning contact allergy to an indicative list of active ingredients of hair cosmetics, namely, p-phenylenediamine (PPD), toluene-2,5-diamine (PTD), persulfates, mostly ammonium persulfate (APS), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG), concerning the prevalence of sensitization, particularly in terms of a comparison (relative risk; RR) between hairdressers and non-hairdressers.

METHODS

Following a PROSPERO-registered and published protocol, eligible literature published from 2000 to February 2021 was identified, yielding 322 publications, and extracted in standardized publication record forms, also considering risk of bias.

RESULTS

Based on 141 publications, the contact allergy prevalence to PPD was 4.3% (95% CI: 3.8-4.9%) in consecutively patch tested patients. Other ingredients were mostly tested in an aimed fashion, yielding variable, and partly high contact allergy prevalences. Where possible, the RR was calculated, yielding an average increased sensitization risk in hairdressers of between 5.4 (PPD) and 3.4 (ATG). Additional evidence related to immediate-type hypersensitivity, experimental results, exposures, and information from case reports was qualitatively synthesized.

CONCLUSIONS

An excess risk of contact allergy is clearly evident from the pooled published evidence from the last 20 years. This should prompt an improvement in working conditions and product safety.

Imidazolidinyl urea activates mast cells via MRGPRX2 to induce non-histaminergic allergy

Imidazolidinyl urea (IU) is used as an antimicrobial preservative in cosmetic and pharmaceutical products. IU induces allergic contact dermatitis, however, the mechanism has not yet been elucidated. Mas-related G protein-coupled receptor-X2 (MRGPRX2) triggers drug-induced pseudo-allergic reactions. The aims of this study were to determine whether IU activated mast cells through MRGPRX2 to further trigger contact dermatitis. Wild-type (WT) and Kit^W-sh/HNihrJaeBsmJNju (MUT) mice were treated with IU to observe its effects on local inflammation and mast cells degranulation in vivo. Laboratory of allergic disease 2 cells were used to detect calcium mobilization and release of inflammatory mediators in vitro. WT mice showed a severe local inflammatory response and contact dermatitis, whereas only slight inflammatory infiltration was observed in MUT mice. Thus, MRGPRX2 mediated the IU-induced activation of mast cells. However, histamine, a typical allergen, was not involved in this process. Tryptase expressed by mast cells was the major non-histaminergic inflammatory mediator of contact dermatitis. IU induced anaphylactic reaction via MRGPRX2 and further triggering non-histaminergic contact dermatitis, which explained why antihistamines are clinically ineffective against some chronic dermatitis.

Occupational contact dermatitis: Retrospective analysis of North American Contact Dermatitis Group Data, 2001 to 2016

BACKGROUND

Patch testing is an important diagnostic tool for suspected allergic contact dermatitis (ACD) in occupational settings.

OBJECTIVE

Provide an overview of occupational skin disease (OSD) and an analysis of occupational ACD in North American patients undergoing patch testing between 2001and 2016.

METHODS

Patients with OSD were analyzed for frequency of allergic reactions to a screening series of allergens, occupational relevance, location of skin disease, and exposure sources. Demographic, occupation, and industry information were recorded.

RESULTS

Of 38,614 patients evaluated, 4471 (11.6%) had OSD, of whom 3150 (70.5%) had ACD. The most common occupationally related allergens included rubber accelerators, preservatives, and bisphenol A epoxy resin. Hands (75.8%), arms (30.0%), and face (15.9%) were common sites of dermatitis. The occupations most affected were service workers and machine operators.

LIMITATIONS

Our cohort may not reflect the general working population.

CONCLUSION

This study identified common occupational allergens, exposure sources, and occupations/industries at risk. This information may help the clinician evaluate and manage patients with occupational contact dermatitis.

Positive Patch Test Reactions to Carba Mix and Thiuram Mix: The North American Contact Dermatitis Group Experience (1994-2016)

BACKGROUND/OBJECTIVE

This study characterizes concomitant reactions to carba mix (CM) and thiuram mix (TM) in a large North American population. Because thiurams and dithiocarbamates have structural similarity, concomitant reactions are expected.

METHODS

The 1994-2016 North American Contact Dermatitis Group data were analyzed. Patients with a final reaction interpreted as "allergic" to either CM or TM were included.

RESULTS

A total of 49,758 patients were tested to both CM and TM. A total of 3437 (6.9%) had positive reactions to CM and/or TM including the following groups: CM+ only (n = 1403, 40.8%), TM+ only (n = 1068, 31.0%), or both (n = 966, 28.1%). A total of 47.5% of TM+ patients were positive to CM and 40.8% of CM+ patients were positive to TM. Male sex, occupationally related dermatitis, and hand involvement were significantly more common in individuals positive to CM and/or TM as compared with those who were negative (P < 0.0001). More than 80% of CM+/TM+ reactions were currently relevant. Gloves were the most common source of CM and TM; clothing and footwear were also frequent.

CONCLUSIONS

Carba mix and TM remain important, clinically relevant allergens. Although significant concomitant reaction frequency was demonstrated, more than half of the patients reacting to either CM or TM would have been missed if both had not been tested, underscoring the importance of testing to both.

A perspective on the safety of parabens as preservatives in wound care products

Antimicrobial and/or preservative ingredients incorporated in wound care products are subjected to certain safety restrictions. However, several of those agents, and paraben preservatives in particular, have been criticised. Conflicting reports on the potential of parabens to induce allergic contact dermatitis, and their assumed oestrogen‐like activity, raised public health concerns about their overall safety. Here, we seek to provide a balanced perspective on the most significant purported adverse health effects, and thereby allay the many misconceptions regarding the safety of parabens. Extensive and long‐term monitoring of paraben allergy frequencies illustrate that allergic reactions are quite uncommon, especially when compared with other antimicrobial and preservative agents. The estrogenic potential of parabens was illustrated to be far less potent than that of natural oestrogen receptor ligands, and the etiological significance of their presence in human tissue has not been established. The general consensus based on investigations by both the scientific community and regulatory agencies indicates that, with current safety regulations regarding their use in place, this effective and well‐documented group of preservatives should not warrant drastic measures to replace them. As such, despite the ongoing concern, it is indicated that, when used at typical concentrations, parabens are unlikely to affect human health.

Thimerosal induces skin pseudo-allergic reaction via Mas-related G-protein coupled receptor B2

BACKGROUND

Thimerosal has been used as a preservative in many products which may cause contact dermatitis. It is the second most common allergen in positive patch test reactions, though being a clinical irrelevant allergen. Thimerosal-induced contact dermatitis is generally considered to be a delayed-type hypersensitivity reaction, but it is difficult to explain the fact that most patients develop an allergic reaction upon first encounter with thimerosal. Recent studies have demonstrated the association between Mas-related G protein coupled receptor X2 (MRGPRX2) and pseudo-allergic reactions which occur at the first contact with stimulation. This suggests the possibility that thimerosal may cause contact dermatitis via MRGPRX2 mediated mechanism.

OBJECTIVES

To investigate the role of Mas-related G-protein coupled receptor B2 (MrgprB2)/MRGPRX2 in contact dermatitis induced by thimerosal.

METHODS

Thimerosal induced pseudo-allergic reactions via MrgprB2/ MRGPRX2 were investigated using a novel skin pseudo-allergic reaction mouse model, footpad swelling and extravasation assays in vivo and mast cell degranulation assay in vitro.

RESULTS

Thimerosal induced contact dermatitis in dorsal skin and footpad swelling in wild-type mice, but had no significant effect in MrgprB2-knockout mice. Thimerosal-induced dermatitis is characterized by infiltration of inflammatory cells and elevation of serum histamine and inflammatory cytokines, rather than elevation of serum IgE level. Thimerosal increased the intracellular Ca²⁺ concentration in HEK293 cells overexpressing MrgprB2/MRGPRX2. Downregulation of MRGPRX2 resulted in the reduced degranulation of LAD2 human mast cells.

CONCLUSIONS

MrgprB2 mediates thimerosal-induced mast cell degranulation and pseudo-allergic reaction in mice. MRGPRX2 may be a key contributor to human contact dermatitis.

Simultaneous Determination of Cysteamine and Cystamine in Cosmetics by Ion-Pairing Reversed-Phase High-Performance Liquid Chromatography

Cysteamine has been used in cosmetics as an antioxidant, a hair straightening agent, and a hair waving agent. However, recent studies indicate that cysteamine can act as an allergen to hairdressers. The objective of this study was to develop and validate a simple and effective reversed-phase high-performance liquid chromatography (RP-HPLC) method for the measurement of cysteamine and its dimer, cystamine. Sodium 1-heptanesulfonate (NaHpSO) was used as an ion-pairing agent to improve chromatographic performance. Separation was performed on a Gemini C18 column (250 mm × 4.6 mm, 5 μm particle size) using a mobile phase composed of 85:15 (v/v) 4 mM NaHpSO in 0.1% phosphoric acid:acetonitrile. UV absorbance was monitored at 215 nm. The RP-HPLC method developed in this study was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, and recovery. Cysteamine and cystamine were chromatographically resolved from other reducing agents such as thioglycolic acid and cysteine. Extraction using water and chloroform resulted in the recovery for cysteamine and cystamine ranging from 100.2-102.7% and 90.6-98.7%, respectively. This validated RP-HPLC method would be useful for quality control and monitoring of cysteamine and cystamine in cosmetics.

North American Contact Dermatitis Group Patch Test Results: 2015-2016

BACKGROUND

Patch testing is an important diagnostic tool for the assessment of allergic contact dermatitis (ACD).

OBJECTIVE

This study documents the North American Contact Dermatitis Group (NACDG) patch testing results from January 1, 2015, to February 28, 2017.

METHODS

At 13 centers in North America, patients were tested in a standardized manner with a screening series of 70 allergens. Data were manually verified and entered into a central database. Descriptive frequencies were calculated, and trends were analyzed using χ test.

RESULTS

A total of 5597 patients were tested. There were 3725 patients (66.6%) who had at least 1 positive reaction, and 2798 patients (50.2%) were ultimately determined to have a primary diagnosis of ACD. A total of 572 patients (10.2%) had occupationally related skin disease. There were 10,983 positive allergic reactions. Nickel remained the most commonly detected allergen (17.5%). Methylisothiazolinone, which was added to the screening series for the 2013-2014 cycle, had the second highest positive reaction rate of allergens tested (13.4%). Compared with the previous reporting periods (2013-2014) and (2005-2014), positive reaction rates for the top 35 screening allergens statistically increased for only 1 allergen: hydroxyethyl methacrylate (3.4%; risk ratios, 1.24 [confidence interval, 1.00-1.54] and 1.46 [confidence interval, 1.23-1.73]). Three newly added allergen preparations-ammonium persulfate (1.7%), chlorhexidine (0.8%), and hydroquinone (0.3%)-all had a reaction rate of less than 2%. Twenty-three percent of the tested patients had at least 1 relevant allergic reaction to an allergen not on the NACDG series; 12% of these were occupationally related. T.R.U.E. Test (SmartPractice Denmark, Hillerød, Denmark) would have hypothetically missed one quarter to almost 40% of reactions detected by the NACDG screening series.

CONCLUSIONS

These results confirm that the epidemic of sensitivity to methylisothiazolinone has continued in North America. Patch testing with allergens beyond a screening tray is necessary for a complete evaluation of occupational and nonoccupational ACD.

Contact Dermatitis Due to Local Cosmetics: A Study from Northern India

Background:

Majority of the cosmetics are synthetic in nature and capable of causing dermatitis among frequent users. Some cosmetics (bindi, sindoor, etc.) that cause serious skin inflammation are specific to Indian culture.

Aim:

To study the prevalence of contact dermatitis due to various cosmetics indigenous among Indian users.

Materials and Methods:

A cross-sectional study of 2,150 patients who attended dermatitis clinic at a regional hospital in north India. A total of 400 of these were suspected of cosmetic dermatitis based on clinical grounds and were subjected to patch test using Indian Standard Series and Cosmetic series kit.

Results:

Among the 400 patients identified for cosmetic dermatitis, 352 (88%) were female and 326 (81.5%) between 20 and 49 years of age. Bindi/kumkum (30%), hair dye (18%), and deodorant/perfume (14%) were primary cosmetics causing contact dermatitis. Patch test with the suspected cosmetics was positive in 52.75% cases. Patients who visited their doctor in the early stages of appearance of symptoms (<3 months) were more likely to have positive patch test.

Conclusion:

Higher incidence of cosmetic dermatitis is observed in adult females aggravated by use of inferior quality cosmetics. Early detection of the disease can be helpful.

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.

Medicinal Plants from North and Central America and the Caribbean Considered Toxic for Humans: The Other Side of the Coin

The consumption of medicinal plants has notably increased over the past two decades. People consider herbal products as safe because of their natural origin, without taking into consideration whether these plants contain a toxic principle. This represents a serious health problem. A bibliographic search was carried out using published scientific material on native plants from Mexico, Central America, and the Caribbean, which describe the ethnobotanical and toxicological information of medicinal plants empirically considered to be toxic. A total of 216 medicinal plants belonging to 77 families have been reported as toxic. Of these plants, 76 had been studied, and 140 plants lacked studies regarding their toxicological effects. The toxicity of 16 plants species has been reported in clinical cases, particularly in children. From these plants, deaths have been reported with the consumption of Chenopodium ambrosioides, Argemone mexicana, and Thevetia peruviana. In most of the cases, the principle of the plant responsible for the toxicity is unknown. There is limited information about the toxicity of medicinal plants used in Mexico, Central America, and the Caribbean. More toxicological studies are necessary to contribute information about the safe use of the medicinal plants cited in this review.

Computer-assisted design/computer-assisted manufacturing systems: A revolution in restorative dentistry

For the better part of the past 20 years, dentistry has seen the development of many new all-ceramic materials and restorative techniques fueled by the desire to capture the ever elusive esthetic perfection. This has resulted in the fusion of the latest in material science and the pen ultimate in computer-assisted design/computer-assisted manufacturing (CAD/CAM) technology. This case report describes the procedure for restoring the esthetic appearance of both the left and right maxillary peg-shaped lateral incisors with a metal-free sintered finely structured feldspar ceramic material using the latest laboratory CAD/CAM system. The use of CAD/CAM technology makes it possible to produce restorations faster with precision- fit and good esthetics overcoming the errors associated with traditional ceramo-metal technology. The incorporation of this treatment modality would mean that the dentist working procedures will have to be adapted in the methods of CAD/CAM technology.

Immunotherapy of allergic contact dermatitis

The term 'immunotherapy' refers to treating diseases by inducing, enhancing or suppressing immune responses. As allergy is an excessive, detrimental immune reaction to otherwise harmless environmental substances, immunotherapy of allergic disease is aimed at the induction of tolerance toward sensitizing antigens. This article focuses on the historical developments, present state and future outlook for immunotherapy with haptens as a therapeutic modality for allergic contact dermatitis. Inspired by the effectiveness of immunotherapy in respiratory allergies, attempts were undertaken at curing allergic contact dermatitis by means of controlled administration of the sensitizing haptens. Animal and human experiments confirmed that tolerance to haptens can be induced most effectively when the induction of tolerance precedes attempted sensitization. In real life, however, therapy is sought by people who are already sensitized and an effective reversal of hypersensitivity seems more difficult to achieve. Decades of research on Rhus hypersensitivity led to a conclusion that immunotherapy can suppress Rhus dermatitis, however, only to a limited degree, for a short period of time, and at a high risk of side effects, which makes this method therapeutically unprofitable. Methodological problems with most available studies of immunotherapy of contact allergy to nickel make any definite conclusions impossible at this stage.

Cutaneous Manifestations of Modern Technology Use

Background:

Modern-age technology is increasingly implicated in traditional dermatologic conditions.

Objective:

This review provides a concise overview of the cutaneous manifestations from modern technology use.

Methods:

We describe a case of laptop computer–induced erythema ab igne and provide a review of the literature pertaining to the etiology, clinical features, diagnosis, and management of reported cases of dermatoses resulting from the use of modern technology.

Results:

Sources of modern technology implicated in the reported cases include video games, laptop computers, personal computers and accessories, and smart and cellular phones. These presentations have primarily been localized to the extremities, particularly the hands and face. Diagnoses were associated with trauma or repetitive strain, irritant contact dermatitis, or allergic contact sensitivities. Removal of the offending agent was most often described as effective in symptom resolution.

Conclusion:

It is important to consider modern-age sources as part of the index of suspicion for diagnosing traditional dermatologic conditions. These manifestations will likely increase over time with the pervasive popularity and use of modern technology. Early recognition of the offending agent will be beneficial in differentiating the etiology for effective management.

Nanoparticles reduce nickel allergy by capturing metal ions

Approximately 10% of the population in the USA suffer from nickel allergy, and many are unable to wear jewellery or handle coins and other objects that contain nickel. Many agents have been developed to reduce the penetration of nickel through skin, but few formulations are safe and effective. Here, we show that applying a thin layer of glycerine emollient containing nanoparticles of either calcium carbonate or calcium phosphate on an isolated piece of pig skin (in vitro) and on the skin of mice (in vivo) prevents the penetration of nickel ions into the skin. The nanoparticles capture nickel ions by cation exchange, and remain on the surface of the skin, allowing them to be removed by simple washing with water. Approximately 11-fold fewer nanoparticles by mass are required to achieve the same efficacy as the chelating agent ethylenediamine tetraacetic acid. Using nanoparticles with diameters smaller than 500 nm in topical creams may be an effective way to limit the exposure to metal ions that can cause skin irritation.

Allergic triggers in atopic dermatitis

Food or environmental allergens play a significant pathogenic role in a subgroup of patients with atopic dermatitis (AD) and can trigger eczema flares. This review focuses on when and which diagnostic and allergen-avoidance measures are beneficial. Diagnosis of allergic triggers may be aided by skin-prick tests measuring serum-specific IgE and/or atopy patch tests (APT) based on the patient's history, and when necessary, oral food challenges (OFC). In a subset of patients, therapeutic measures, such as elimination of the incriminated allergen(s), can lead to marked improvement of AD; this is especially true for food allergens, but can also apply to inhalant allergens.

Results of patch testing to personal care product allergens in a standard series and a supplemental cosmetic series: an analysis of 945 patients from the Mayo Clinic Contact Dermatitis Group, 2000-2007

BACKGROUND

Patch testing to a standard screening series of allergens in combination with supplemental cosmetic allergens is often used to diagnose allergic contact dermatitis due to personal care products.

OBJECTIVE

To report results of patch testing to skin care product allergens contained in a standard series and a supplemental cosmetic series and to compare efficacy of this combined series in detecting positive reactions to personal care product allergens with the efficacy of various standard screening series.

METHODS

Positive reaction rates to skin care product allergens were tabulated for patients who underwent patch testing to both standard and cosmetic series allergens at Mayo Clinic between 2000 and 2007. Data were compared with skin care allergens detected on standard screening series, including the thin-layer rapid use epicutaneous (TRUE) test.

RESULTS

Of 945 patch-tested patients, 68.4% had at least one positive reaction and 47.3% had at least two positive reactions. Also, 49.4% of patients reacted to at least one preservative; 31.2% reacted to at least one fragrance/botanical additive. Compared with use of our standard series and cosmetic series, use of the TRUE test would have missed 22.5% of patients with preservative allergy, 11.3% with fragrance/botanical allergy, and 17.3% with vehicle allergy.

LIMITATIONS

Various allergens tested over time, patch test reading by residents, and lack of confirmation of allergen in personal care products.

CONCLUSION

Standard patch-test screening series miss a substantial number of patients with skin care product ingredient allergy.

p-Phenylenediamine sensitization and occupation

BACKGROUND

p-Phenylenediamine (PPD) is an extreme delayed-type skin sensitizer, and is relevant in both occupational and non-occupational exposures.

OBJECTIVES

To estimate the prevalence of PPD sensitization in a population of consecutive patients with suspected allergic contact dermatitis who attended units of dermatology or occupational medicine in north-eastern Italy and to investigate the association between their PPD sensitization and occupation.

PATIENTS/MATERIALS/METHODS

A total of 14,464 patients (67.6% women and 32.4% men) with suspected allergic dermatitis underwent patch testing. The associations between patch test results and occupations were studied by multivariate logistic regression analysis.

RESULTS

In both sexes, PPD sensitization was significantly associated with hairdressing and beauty occupation [women, odds ratio (OR) 6.58, 95% confidence interval (CI) 3.76-11.50; men, OR 22.3, 95% CI 4.18-119]. In the female group, PPD sensitization was also significantly higher in professional drivers (OR 5.31, 95% CI 1.76-16.1), barmaids (OR 1.89, 95% CI 1.04-3.44), and cleaners (OR 1.82, 95% CI 1.24-2.68). In the male group, PPD sensitization was significantly higher in bakers and waiters (OR 13.0, 95% CI 1.38-123), household workers (OR 8.46, 95% CI 1.68-42.8), and printers (OR 5.68, 95% CI 1.50-21.5).

CONCLUSIONS

Our study showed that workers in several occupations may be at higher risk of developing sensitization to PPD. It is of importance to reduce possible exposure to PPD-crossreacting substances in these occupations.

Occupational dermatosis

Occupational Dermatosis is described as any alteration in the skin, mucosa or annexes that is directly or indirectly caused, conditioned, maintained or aggravated by agents present in the occupational activity or work environment. The authors of the present study describe the importance of the topic and the epidemiology and etiopathogeny of the main forms of occupational dermatoses: allergic and irritative contact dermatitis, phytodermatitis, acne (elaioconioses and chloracne), keratosis, cancers, foreign body granuloma, infections, onychias, and ulcerations. Clinical findings of occupational dermatosis are presented in relation to various professions. Laboratory tests used to diagnose this condition are analysed, with special emphasis on patch testing, which is the gold standard. Information about the treatment and prevention of this disorder is provided. Collective and individual measures, especially regarding the proper use of individual protection equipment for the prevention of occupational dermatosis, are detailed.

Frequency of sensitization to common allergens: comparison between Europe and the USA

BACKGROUND

Previously, contact allergy to formaldehyde and quaternium-15 was found to be more prevalent in the United States than in Europe. No such data have been assessed for other contact allergens.

OBJECTIVE

Determine any differences in frequencies of sensitization to contact allergens in the United States and Europe.

METHODS

Literature study. Comparison of reported frequencies of sensitization to contact allergens routinely tested both in the United States and Europe in recent, large, multicentre studies. Because of the heterogeneity of studies and background parameters, statistical evaluation was not attempted.

RESULTS

Major differences were found only for neomycin (USA 10.0-11.8%, mean 11.4%; Europe 1.2-5.4%, mean 2.6%). Most allergens had somewhat higher prevalence in the United States, with rates versus Europe ranging from 1.3 to 1.9.

CONCLUSIONS

Contact allergy to neomycin is much more prevalent in the United States. Stricter selection of patients for patch testing in United States tertiary referral centres may result in 50% more positive reactions compared to European studies.

Allergic and Non-Allergic Drug Hypersensitivity Reactions in Children

Adverse drug reactions (ADR) are an important medical problem. The aim of this study is to investigate the clinical characteristics of children with ADR and to assess the tolerability of alternative drugs in children (under 16 yrs of age) with a history of ADR. We studied 278 children (132 males and 146 females). Patients were studied by recording personal history and performing in vivo skin testing, in vitro laboratory tests and challenge tests. Patients who had experienced mild adverse reactions underwent challenge tests without any premedication; patients with a clinical history of moderate reactions, received a premedication with sodium cromolyn 30 min before the oral challenge; patients with a clinical history of severe reactions or undergoing parenteral challenges, were given an antihistamine 30 minutes before. A total of 660 adverse events were reported with 126 different drugs involved. Antimicrobial agents were the most involved drugs (51.7%). Non-steroidal anti-inflammatory drugs were involved in 22.7% of episodes. The most reported symptoms were cutaneous. Allergy testing was negative in 272 patients. A diagnosis of drug allergy was reported for 6 patients. A total of 669 challenge tests were performed. 639 were negative at first attempt while 22 were positive. Eight were repeated using a different premedication and resulted negative. Hypersensitivity drug reactions in children are mainly non-allergic. A premedication with sodium cromolyn or with oral H1-antihistamines may be useful in preventing ADR.