Diagnosing lanolin contact allergy with lanolin alcohol and Amerchol L101

Sensitization to Lanolin in North-Eastern Italy, 1997-2021: Prevalence, Risk Factors and the Impact of Occupation

Background: Direct skin contact with items containing lanolin can induce sensitization and development of contact dermatitis (CD). This multi-centric study investigated prevalence of lanolin sensitization among 30,269 outpatients from North-Eastern Italy patch tested during 1997-2021. Methods: European baseline and extended Triveneto series were applied on the upper part of patients' back and removed after 48 h. Risk factors for lanolin sensitization were investigated by multiple logistic regression analysis, reporting adjusted odds ratios (aOR) with 95% confidence interval (95%CI). Results. Overall lanolin patch test positive ratio (PTPR) was 1.64% (=501/30,629), with variability over time and by research center. The body area most frequently affected by CD were hands (36.32%), followed by face (19.52%) and legs (8.09%), with a lanolin PTPR of 1.68%, 1.37% and 3.07%, respectively. Prevalence of occupational CD was 8.24%, and 1.83% patients with occupational CD patch tested positive against lanolin. Lanolin sensitization was significantly higher in males (aOR = 1.34; 95%CI: 1.08; 1.65) and among patients with leg CD aged 49-60 years (aOR = 2.34; 95%CI: 1.20; 4.57) or older than 60 (aOR = 4.21; 95%CI: 2.59; 6.85). Sub-group analysis confirmed the significantly higher sensitization rate of older patients with leg CD, with much stronger effect size in females 61+ years old (aOR = 5.33; 95%CI 2.87; 9.89) than males in the same age group (aOR = 2.92; 95%CI: 1.34; 6.39). Moreover, female house painters were more likely to test positive to lanolin. Conclusions: The variability of lanolin PTPR over time and by research center endorsed the ongoing debate on the relevance of the respective skin reaction. Clinicians assessing patients with dermatitis should collect information on potential risk factors for lanolin sensitization, particularly use of skin care products containing the hapten. Occupational exposure to lanolin-containing varnishes should also be considered.

A review of the key ingredients in industrial formulations of baby wet wipes

The skin of newborns is classified as sensitive, with a higher risk of skin barrier disruption and irritation of a diapered area. Despite dermatologist recommendations to use only water and a cloth for cleaning, most of the population still relies on the comforts of modern parenting, which includes intensive daily usage of baby wet wipes. Novel baby formulations are designed following the concept of infant skin health, containing a gentle cleanser, suitable emollient, and buffer system enabling a slightly acidic pH value and they are free of ethyl alcohol. Thus, it is important to understand the chemical background of such a complex liquid formulation, with emphasis on its safety. In line with this, the present paper discusses the scientific background of various chemical compounds found in baby wipe formulations to improve the understanding of wet wipe designs and direct them toward more skin-friendly solutions.

Trends in contact sensitization, results, and implications from a contact dermatitis clinic in Israel

BACKGROUND

The baseline series includes common allergens, evolves over time, and differs by location. Our study aims to characterize allergen sensitization trends among the Israeli population during the last two decades, compare our results to American and European registries, as well as to highlight significant allergens in additional series outside the European baseline series (OEBS).

METHODS

We analysed patch test results of 2086 patients from a designated contact dermatitis clinic in Tel Aviv between 2019 and 2022, compared them to European and North American registries and to 2156 patch test results conducted in Israel two decades ago.

RESULTS

38.6% of patients had at least one positive reaction to an allergen in the European baseline series (EBS), nickel sulphate (14.6%), fragrance mix I (4.6%), and Methylchloroisothiazolinone methylisothiazolinone (MCI/MI; 3.7%) were the most common among them. N-Isopropyl N-Phenyl-4-Phenylenediamine (NIPPD; 0%), Propolis (0.1%), Sesquiterpene lactone mix (0.1%), and Budesonide (0.1%) elicited a sensitization frequency significantly lower than the proposed threshold for baseline inclusion. Chi-square test revealed a statistically significant decrease (p < 0.05) in the sensitization frequency of fragrance mix I, Formaldehyde, Potassium dichromate, Neomycin sulphate, Myroxylon pereirae, Sesquiterpene lactone, and NIPPD during the last two decades. The overall sensitization frequency to the majority of allergens was lower in our cohort in comparison to the North American and European registries.

CONCLUSIONS

MCI/MI and 2-hydroxyethyl methacrylate-2 (HEMA) are common, relevant allergens, with high SPIN (significance and prevalence index number) and should be better regulated by the authorities. While among the EBS, NIPPD, Propolis, Sesquiterpene lactone, and Budesonide usually do not elicit a positive reaction and therefore should be reconsidered in baseline series, among the OEBS, Chloramphenicol, Quaternium 15, Propyl gallate, and Amerchol L101 have elicited high SPIN values and should be vigilantly examined in the suitable clinical scenario. Significantly lower sensitization frequency to propolis raises the possibility of a protective effect due to early oral exposure among the Israeli population.

The new Italian SIDAPA Baseline Series for patch testing (2023): an update according to the new regulatory pathway for contact allergens

Allergic contact dermatitis (ACD) is a common inflammatory skin disease caused by delayed hypersensitivity to chemical and biotic contact allergens. ACD significantly affects the patients' quality of life negatively impacting both occupational and non-occupational settings. Patch testing is the gold standard diagnostic in vivo test to precise the ACD etiology and to correctly perform prevention. According to the Italian Medicines Agency (AIFA) legislative decree no. 178 of 29th May 1991, allergens are defined as medicines and therefore they are subject to strict regulation. In 2017, AIFA (decree no. 2130/2017) started a procedure to regulate contact allergens on the Italian market and actually the contact allergens temporarily authorized are reported in AIFA decree no. 98/2022, valid until November 2023. The availability on the market of contact allergens to diagnose ACD and continuous updating on the basis of new epidemiological trends are mandatory, jointly with the continuous update of the baseline and integrative series for patch testing. For this reason, the scientific community represented in Italy by the Skin Allergies Study Group of SIDeMaST (Italian Society of Dermatology and Venereology) and SIDAPA (Italian Society of Allergological, Occupational and Environmental Dermatology) are constantly working, in close relationship with the European scientific communities with large expertise in this important sector of the modern Dermatology. Herein, we report the setting up of regulatory legislation by AIFA and the new Italian Adult Baseline Series for patch testing.

Allergic Contact Dermatitis in the Older Adults: A Comparative Cross-Sectional Study

Background: Allergic contact dermatitis (ACD) is a significant health problem in older adults. Reports in the literature regarding the prevalence of ACD in older adults are various and inconsistent. In contrast, the data regarding contact irritant dermatitis are more consistent. Objective: To compare ACD characteristics in older adults versus the adult population aged 18-45 years. Methods: We conducted a retrospective controlled study. Data were obtained from the medical records of 4199 patients. We collected information regarding age, gender, atopic diathesis, anatomical distribution of the rash, reactions to patch tests, and final diagnosis. Results: The frequency of positive reactions in patch testing was lower in the older adult group than in the younger population, but the frequency of clinically relevant positive reactions was higher in the older adults. There was no statistically significant difference in the final diagnosis of ACD between the groups. The most common allergens among the older adult population were fragrance mix, preservatives (Methylchloroisothiazolinone/methylisothiazolinone [MCI/MI]), and nickel sulfate. Conclusion: This study, the first of its kind in Israel to include a large group of older adult patients, contributes to a better understanding of clinical parameters related to ACD among older adults. Consequently, it will hopefully contribute to lowering the disease burden.

Long-Term North American Trend in Patch Test Reactions: A 32-Year Statistical Overview (1984-2016)

Background: Allergic contact dermatitis (ACD) remains a public health issue worldwide, despite regulations intended to minimize sensitization. With up-to-date knowledge about which chemicals continue to have high allergenicity, the government/industry can refocus their efforts to be most effective. Objective: We reviewed updated data showing common allergens that elicit ACD to determine the progress in reducing sensitization to inform public health policy, government regulation, and industry standards. Methods: We compiled data from the North American Contact Dermatitis Group showing patch test results from 1984 to 2016 for 153 compounds. Using these data, we analyzed the trends over time of positive test reactions to determine whether they are increasing or decreasing. Results: Of the 47 compounds with sufficient data to analyze, 23 had a decreasing proportion of positive patch test results over the whole period. An additional 5 had a decreasing proportion over a shorter period. Finally, 4 had an increasing proportion over any period: compositae mix, methylchloroisothiazolinone/methylisothiazolinone, nickel sulfate, and thimerosal mix. Conclusions: The data strongly indicate decreasing and increasing frequency trends and challenge us to seek explanations, which are not yet clear. It is hoped that these data can be valuable in informing public health policy, government, and industry.

Lanolin

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

Long-Term North American Trend in Patch Test Reactions: A 32-Year Statistical Overview (1984-2016)

BACKGROUND

Allergic contact dermatitis (ACD) remains a public health issue worldwide, despite regulations intended to minimize sensitization. With up-to-date knowledge about which chemicals continue to have high allergenicity, the government/industry can refocus their efforts to be most effective.

OBJECTIVE

We reviewed updated data showing common allergens that elicit ACD to determine the progress in reducing sensitization to inform public health policy, government regulation, and industry standards.

METHODS

We compiled data from the North American Contact Dermatitis Group showing patch test results from 1984 to 2016 for 153 compounds. Using these data, we analyzed the trends over time of positive test reactions to determine whether they are increasing or decreasing.

RESULTS

Of the 47 compounds with sufficient data to analyze, 23 had a decreasing proportion of positive patch test results over the whole period. An additional 5 had a decreasing proportion over a shorter period. Finally, 4 had an increasing proportion over any period: compositae mix, methylchloroisothiazolinone/methylisothiazolinone, nickel sulfate, and thimerosal mix.

CONCLUSIONS

The data strongly indicate decreasing and increasing frequency trends and challenge us to seek explanations, which are not yet clear. It is hoped that these data can be valuable in informing public health policy, government, and industry.

A Review on Metabolic Paradoxes and their Impact on Metabolism

The current review paper portrays the important link of different nutrients like trace elements, proteins, fatty acids, vitamins, and amino acids with the immune system as well as information related to metabolic paradoxes. Optimum working of the metabolic system is essential because it gives various types of supplements to the human body and aid in chemical pathways. Here related data have been retrieved from two databases i.e., PubMed and Google scholar to grasp detailed knowledge about micronutrients and nutrients as well as their association in the metabolic system. Like protein play important role in the normal development of different immune components, amino acids including alanine, Arginine, and glutamic acid properly control the movement of neutrophils, macrophages, and cytokines. While fatty acids act as an anti-inflammatory agent because they possess the ability to inhibit the expression of the MHC class. Apart from these, many essential molecules like uric acid, proteins, calcium, lanolin are also obtained as end products after catabolic and anabolic reactions, and it was found that the uric acid paradox has a cancer inhibitory role. Additionally, TGF and IL-6 paradoxes have a role in the development of tumors, the onset of diabetes, and low-grade inflammatory disorders respectively. However, the entire functioning of metabolic processes depends upon daily diet because humans get the important nutrient from the diet which further vital role in the immune system. Moreover, it was also observed that calcium paradox is related to heart disorders because high calcium accumulation leads to cardiac disorders. Thus, the complete knowledge about these essential components as well as metabolic paradoxes is very important due to their antagonistic role to plan better and improved therapeutic strategies for various diseases.

The Added Value of Patch Testing Beyond the Baseline Tray

BACKGROUND

The patch test is the standard for diagnosing allergic contact dermatitis. Standardized trays allow the examination of the most prevalent allergens, whereas customized trays are more appropriate for addressing specific allergens and require expertise. They are therefore usually performed in specialized clinics.

METHODS

We assessed the results of 4355 patch tests performed between 2012 and 2020 in a contact dermatitis clinic located in a large tertiary medical center. All patients were tested using the European baseline series and additional trays as clinically indicated. We assessed the frequency of relevant positive reactions outside the European baseline series. We then examined the added value and number of tests (NNTs) that need to be performed to elicit one relevant positive reaction per tray and common allergens.

RESULTS

Nine hundred fifty-four patients (21.9%) had 1 or more positive relevant reactions; 43.3% tested positive for an allergen outside the European baseline series (OEBS). The acrylate and fragrance trays were highly represented among the positive and relevant reactions OEBS with NNTs of 4.4 and 6.8, respectively. 2-Hydroxyethyl methacrylate is the most prevalent allergen OEBS and is considered a marker for acrylate sensitivity with a high rate of cross-reactions and concordance rate of 85%, justifying its addition to the EBS in 2018. Other highly represented allergens include chloramphenicol, 2-hydroxyethyl acrylate, and Amerchol L-101, a lanolin derivative. The cosmetics and textile trays, although often tested, have relatively low added values of 3.7% and 2.3%, respectively. Surprisingly, the cutaneous adverse drug reaction series tray (CAD-1000) yielded no positive reactions, whereas testing the patients' medication yielded positive results in 10.9% of the cases.

CONCLUSIONS

Expanded patch testing is crucial to accurately diagnose allergic contact dermatitis and almost doubles the number of patients with relevant positive reactions. Acrylate sensitivity is an emerging epidemic with a high positive reaction rate and low NNT, as is sensitivity to the allergens in the fragrance tray. 2-Hydroxyethyl methacrylate is a reliable marker for acrylate sensitivity with a concordance rate of 85%. Chloramphenicol is a common culprit and should be added to the standard tray in countries with a high usage rate. A low NNT was also observed when testing the patients' own cosmetics and medications; this should, therefore, be encouraged. The textile tray yielded a relatively high NNT; however, it should be performed when clinically indicated in the absence of a reliable marker in the EBS.

Frequency of Allergenic Ingredients in Antifungal Creams

BACKGROUND

Allergic contact dermatitis (ACD) may occur secondary to topical antifungals containing potential allergens in their vehicles. Variation of allergenic ingredients among commonly used antifungal creams (AFCs) has not been well characterized.

OBJECTIVE

The study goal was to assess the frequency of allergenic ingredients in 4 commonly used topical AFCs.

METHODS

Topical AFCs (clotrimazole, ketoconazole, miconazole, and terbinafine) were selected, and the ingredient lists for these products were obtained from the US Food and Drug Administration's Online Label Repository via a proprietary name search. A systematic literature review was performed using the ingredient name on MEDLINE (PubMed) database to identify reports of ACD confirmed by patch testing.

RESULTS

Of the 20 ingredients analyzed, 6 had frequent allergenic potential. Propylene glycol was the most common cause of ACD identified in the literature and is an ingredient in ketoconazole 2% and miconazole nitrate 2%. Ketoconazole 2% and miconazole nitrate 2% creams contained the highest number of potential allergens (n = 3) among the 4 creams analyzed.

CONCLUSIONS

Of the 4 creams, terbinafine hydrochloride 1% and clotrimazole 1% contained the least number of potential allergenic ingredients. Awareness of the allergenic potential of commonly used AFCs may help health care providers when evaluating patients with ACD.

Environmental Causes of Dermatitis

Environmental, or exogenous, dermatitis is comprised of irritant and allergic contact dermatitis, which account for 80% and 20% of cases of contact dermatitis, respectively. Contact dermatitis is extremely common, and failure to diagnose this entity may result in overlooking a potentially curable driver of disease. In this review, we describe how clinical features, such as morphology or history, can assist in distinguishing exogenous from endogenous causes of dermatitis, and allergic from irritant contact dermatitis. Additionally, we provide an overview of common contact allergens and how dermatitis distribution can suggest possible culprit allergens. Patch testing is needed to confirm contact allergy.

Pediatric Allergic Contact Dermatitis

Allergic contact dermatitis (ACD) affects up to 20% of adults and children, although children are infrequently patch tested. Available data suggest that children and adults, with or without atopic dermatitis, have the same prevalence of ACD. Patch testing is the gold standard for evaluation of ACD. The Pediatric Baseline Series was recently published by expert consensus for use in pediatric patch testing, with additional allergens tested as guided by history. This article examines methods of patch testing and up-to-date data on pediatric ACD. The top allergens are reviewed, and avoidance strategies are discussed.

Prevalence and Trend of Allergen Sensitization in Adults and Children with Atopic Dermatitis Referred for Patch Testing, North American Contact Dermatitis Group Data, 2001-2016

BACKGROUND

The association between atopic dermatitis (AD) and allergic contact dermatitis (ACD) is controversial.

OBJECTIVE

To analyze the prevalence, reaction strength, and trends of the most commonly positive and relevant allergens in patients with AD referred for patch testing.

METHODS

This was a retrospective analysis of 38,482 patients from the North American Contact Dermatitis Group, 2001 to 2016.

RESULTS

Most adults (56.0%) and children (52.8%) with a history of AD had a final diagnosis of ACD. Adults (66.5% vs 65.6%; χ², P = .1459) and children (61.4% vs 62.3%, P = .7074) with or without a history of AD had similar proportions of one or more allergic patch test reactions. Adults with a history of AD had a greater number of allergic patch test positive reactions than those without it (2.0 ± 2.4 vs 1.9 ± 2.3; t test, P < .0001), whereas children did not (1.5 ± 1.8 vs 1.4 ± 1.6; P = .3839). Nickel sulfate, methylisothiazolinone, formaldehyde, fragrance mix I, sodium gold thiosulfate, and thimerosal were the most common allergens in adults and children with a history of AD. In multivariable logistic regression models, adults with versus without a history of AD had increased odds of reacting to 10 of the top 25 North American Contact Dermatitis Group screening allergens. Most allergens had similar strengths of reaction in adults or children with and without a history of AD or a current AD diagnosis; cobalt, fragrance mix I, and propylene glycol had weaker reactions. In multivariable logistic regression, adults with versus without an AD history had increased odds of relevance for 10 of the 25 most currently relevant allergens, whereas children with an AD history did not have increased relevance for any specific allergens.

CONCLUSIONS

Most patients referred for patch testing with AD history had a final diagnosis of ACD. Patients with AD history had a similar likelihood of having a positive patch test reaction as those without an AD history. Adults with an AD history had a higher number of positive patch test reactions.

Clinical relevance of positive patch test reactions to lanolin: A ROAT study

Background

Lanolin is often included when patch testing for common contact allergens. The clinical relevance of a positive patch test reaction to lanolin markers is, however, still a subject for debate.

Objectives

To evaluate Amerchol L101 as a marker of lanolin allergy and investigate the clinical impact of lanolin‐containing moisturizers on healthy and damaged skin using the repeated open application test (ROAT).

Methods

Twelve test subjects and 14 controls were patch tested with Amerchol L 101 and additional lanolin markers. Subsequently, a blinded ROAT was performed on the arms of the study participants for 4 weeks. Each participant applied a lanolin‐free cream base and two different lanolin‐containing test creams twice daily on one arm with intact skin and on the other arm with irritant dermatitis, induced by sodium lauryl sulfate (SLS).

Results

Eleven test subjects (92%) had positive patch test reactions to Amerchol L 101 when retested and one test subject (8%) had a doubtful reaction. None of the study participants had any skin reactions to the ROAT on intact skin and all participants healed during the ROAT on damaged skin.

Conclusions

Lanolin‐containing emollients do not cause or worsen existing dermatitis when performing ROAT in volunteers patch test positive to Amerchol L101.

Developing a cosmetic series: Results from the ESSCA network, 2009-2018

BACKGROUND

There is considerable variability across European patch test centres as to which allergens are included in local and national cosmetics series.

OBJECTIVES

To propose a standardized, evidence-based cosmetic series for Europe based on up-to-date analysis of relevant contact allergens.

METHODS

We collated data from the European Surveillance System on Contact Allergies (ESSCA) from 2009 to 2018 to determine which cosmetic allergens produce a high yield of contact allergy. Contact allergens with a prevalence of >0.3% that were considered relevant were included. Rare contact allergens were excluded if deemed no longer relevant or added to a supplemental cosmetic series for further analysis.

RESULTS

Sensitization prevalences of 39 cosmetic contact allergens were tabulated. Thirty of these allergens yielded >0.3% positive reactions and are therefore included in our proposed European cosmetic series. Six were considered no longer relevant and therefore excluded. Three were included in a supplementary European cosmetic series. An additional nine allergens were included in either the core or supplemental European cosmetic series following literature review.

CONCLUSION

We have derived a potential European cosmetic series based upon the above methods. This will require ongoing investigation based upon the changing exposure profiles of cosmetic allergens as well as new and evolving substances.

Pediatric contact dermatitis: what's new

PURPOSE OF REVIEW

Allergic contact dermatitis (ACD) was once thought to be rare in children but recent studies have demonstrated that the prevalence of ACD is common and appears to be increasing in children. Current trends including toys, hobbies, and personal care products may play a role in potentially new allergen exposure or resurgence of certain allergens, making ACD a moving target in children.

RECENT FINDINGS

ACD and atopic dermatitis can coexist and certain clinical features can help differentiate ACD from endogenous atopic dermatitis in children. It is important to consider ACD in children with recalcitrant atopic dermatitis or dermatitis with atypical distribution. Patch testing has become a more common practice in children. In 2018, the first expert consensus-derived pediatric baseline series consisting of 38 allergens was proposed to aid in the diagnosis of ACD in children. Comparing recent patch testing data in the pediatric population, the top allergens ubiquitously identified were nickel, cobalt, neomycin, Myroxylon pereirae (balsam of Peru), fragrance mix I, fragrance mix II, methylisothiazolinone, methylchloroisothiazolinone/ methylisothiazolinone, formaldehyde, and lanolin.

SUMMARY

ACD is a common problem in children. Detection through patch testing, avoidance of offending allergens, and prevention of common allergens are the main focus of management of ACD in children.

Allergic Contact Dermatitis Secondary to Moisturizers

Background: Moisturizers are cosmetic products used routinely to manage various skin conditions. Even though moisturizers are often thought to have minimal or no adverse reactions, allergic contact dermatitis (ACD) to these products can develop in some cases. Methods: We studied ingredients included in 3 of the most commonly used moisturizer brands, identified their presence in standard patch testing series, and evaluated their allergenic potential, categorizing the allergens as frequent or infrequent. The standard patch testing series used as reference were the Thin-layer Rapid Use Epicutaneous patch test (T.R.U.E. test), the North American Contact Dermatitis Group (NACDG) screening standard series, and the American Contact Dermatitis Society (ACDS) core allergen series. Results: Aveeno, Cetaphil, and Cerave products had a total of 12, 14, and 9 potential allergens, respectively, the majority of which were infrequent and not included in standard patch testing series. Conclusion: Being aware of the allergenic potential of commonly used moisturizers may help healthcare providers when evaluating patients with ACD. Further testing is recommended in a targeted manner when suspecting ACD with negative standard patch testing series or when ACD is refractory to treatment.

Contact Allergy-Emerging Allergens and Public Health Impact

Contact allergy (sensitisation) and allergic contact dermatitis (ACD) resulting from it have a considerable public health impact. For the present review, all pertinent articles were systematically searched via Medline and Web of Science™; additionally, all available issues of the journals "Contact Dermatitis" and "Dermatitis" were manually searched, covering the years 2018-2019, thereby extending and re-focusing a previous similar review. New allergens, or previously described allergens found in a new exposure context or of other current importance, are described in sections according to substance classes, e.g., metals, preservatives, fragrances. As a common finding in many investigations, a lack of information on product composition has been noted, for instance, regarding a newly described allergen in canvas shoes (dimethylthiocarbamylbenzothiazole sulfide) and, most notably, absence of co-operation from manufacturers of glucose-monitoring devices and insulin pumps, respectively. These latter devices have been shown to cause severe ACD in a considerable number of diabetic patients caused by the liberation of isobornyl acrylate and N,N'-dimethylacrylamide, respectively, as demonstrated by an international collaboration between dermatologists and chemists. Improved and complete ingredient labelling for all types of products, and not just cosmetics, must be put on the legislative agenda.

Diagnosing lanolin contact allergy with lanolin alcohol and Amerchol L101

Background

The prevalence of lanolin contact allergy in dermatitis patients varies from 1.2% to 6.9%. Different lanolin derivatives are used in patch testing.

Objectives

To determine which combination of lanolin derivatives is most effective in patch testing for the diagnosis of lanolin contact allergy.

Methods

A retrospective analysis of patients patch tested between 2016 and 2017 was performed. Patients were eligible if they had been tested with lanolin alcohol 30% pet., Amerchol L101 50% pet., and a supplementary series containing other lanolin derivatives. Lanolin alcohol and Amerchol L101 were tested in duplicate.

Results

Of 594 patients, 28.6% (95% confidence interval [CI]: 25.1%‐32.3%) had a positive patch test reaction to at least one lanolin derivative. Reactions to lanolin alcohol (14.7%, 95%CI: 11.3%‐18.2%) and Amerchol L101 (15.0%, 95%CI: 11.5%‐18.5%) were common in the routinely tested series. Reactions to other test preparations were significantly less frequent (P < 0.05). The addition of Amerchol L101 to lanolin alcohol significantly increased the number of positive cases (odds ratio 1.79, P < 0.001).

Conclusions

The combination of lanolin alcohol and Amerchol L101 is effective in patch testing for the diagnosis of lanolin contact allergy. Routinely testing with other lanolin derivatives may not be worthwhile, as it detects only a few additional patients.