Diagnosis and Prevalence of Lanolin Allergy

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.

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.

Lanolin Allergic Reactions: North American Contact Dermatitis Group Experience, 2001 to 2018

BACKGROUND

Lanolin is an important cause of allergic contact dermatitis.

OBJECTIVES

The aims of this study were to describe the epidemiology of lanolin allergy and to assess trends in patch test reactions to lanolin over time.

METHODS

This study used a retrospective analysis of patients patch tested with lanolin alcohol 30% or Amerchol L-101 50% in petrolatum by the North American Contact Dermatitis Group between 2001 and 2018 (n = 43,691).

RESULTS

Overall, 1431 (3.3%) had a positive reaction, and 1238 (2.8%) were currently relevant. Prevalence of lanolin allergy was 4.63% between 2011 and 2018 (P < 0.0001). Most lanolin-allergic patients had + (52%) reactions; 18%, and 6% had ++ and +++ reactions, respectively. Common primary anatomic sites of dermatitis were the hands (20.7%), scattered/generalized distribution (19.6%), and face (17.0%). Allergic reactions to lanolin were more common in children (4.5%) than in adults (3.2%, P = 0.0018). Compared with nonallergic patients, lanolin-allergic patients were more likely to have history of eczema or hay fever, male sex, older than 40 years, or Black race (P < 0.05). Common lanolin sources were personal care products and drugs/medications. Only 2.24% of the positive reactions were linked to occupation.

CONCLUSIONS

Lanolin sensitivity was common. Reactions were often clinically relevant and linked to personal care products and medications.

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.

Lipsticks History, Formulations, and Production: A Narrative Review

A considerable amount of literature has been published on several aspects of lipsticks production. To date, there is no collation of studies related to lipsticks production that has been published. This review was conducted to examine information about the history of lipsticks; ingredients used in the preparation of lipsticks, focusing on the natural and chemical ingredients; methods of preparation for the lipsticks; and the characterization of the lipsticks. A literature search for English language articles was conducted by searching electronic databases including Web of Science, Scopus, PubMed, and Google Scholar. Overall, the evidence indicates that lipsticks have been used since ancient times and are among the highest demand cosmetics. The findings of this review summarize those of earlier studies that explained the use of different types of ingredients in the manufacturing processes of lipsticks. It highlights the importance of using green technology and ingredients to fabricate lipsticks to avoid potential side effects such as skin irritation and allergy reaction.

Contact Allergy in Canada Versus United States: Analysis of the North American Contact Dermatitis Group Data 2005-2016

Differences in consumer product availability, distribution, and use may lead to national differences in contact sensitization frequencies.

OBJECTIVE

The aim of the study was to describe the differences in contact allergy between the United States (US) and Canada.

METHODS

This is a retrospective cross-sectional analysis of the North American Contact Dermatitis Group data from 2005 to 2016. Frequencies of demographics, clinical characteristics, positive reactions, trends, and occupations were calculated.

RESULTS

A total of 28,640 patients underwent patch testing. At least 1 positive patch test was observed in 18,599 patients (US, 11,641 [66.5%]; Canada, 6958 [62.5%]). When comparing the 2 groups, US positive reactions were more likely to occur in male patients (odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.31-1.49), older than 40 years (OR = 1.30, 95% CI = 1.22-1.38), Black (OR = 2.67, 95% CI = 2.24-3.19) or Hispanic race (OR = 3.53, 95% CI = 2.61-4.78), and/or patients with scattered generalized dermatitis (OR = 1.96, 95% CI = 1.80-2.13). They were less likely to occur in patients with eczema (OR = 0.61, 95% CI = 0.57-0.65) and Asian race (OR = 0.50, 95% CI = 0.44-0.56). Nickel (US, 16.0%; Canada, 22.4%) and methylisothiazolinone (US, 13.4%; Canada, 11.0%) were the top allergens. The third most frequent was neomycin (US, 11.7%) and fragrance mix I (Canada, 10.2%).

CONCLUSIONS

National differences in allergen prevalence and trends exist in North America.

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.

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.

Natural ingredients in cosmetic products-A suggestion for a screening series for skin allergy

BACKGROUND

Naturally derived cosmetic product ingredients of both plant and animal origin are being included increasingly in product formulations in order to cater to consumer preferences. They may be an overlooked cause of reactions to cosmetic products in some patients with dermatitis.

OBJECTIVES

To identify naturally derived cosmetic product ingredients with allergenic potential (type I and type IV) and propose a cosmetic screening test series.

METHODS

The study was conducted in two steps. The first step was a market survey using a nonprofit application helping consumers avoid problematic substances in cosmetic products. The application contained 10 067 cosmetic products that were label checked for naturally derived cosmetic product ingredients. The second step was a literature search to examine how frequently the naturally derived ingredients were described and related to allergic reactions in cosmetics or other topically administered products.

RESULTS

We identified 121 different naturally derived cosmetic product ingredients that were included in at least 30 cosmetic products. In total, 22 ingredients were selected for a screening test series.

CONCLUSIONS

We propose a supplemental patch test and a prick test screening series with naturally derived cosmetic product ingredients for patients with skin reactions to cosmetic products, aiming to identify a cause in more patients than is currently possible.

Allergic Contact Dermatitis to Operating Room Scrubs and Disinfectants

BACKGROUND

Both surgical personnel and patients undergoing procedures are exposed regularly to different antiseptic chemicals in various forms. Little is known about the ingredients in these antiseptics and the risk these products may provoke allergic contact dermatitis.

OBJECTIVE

The aim of the study was to identify and characterize common allergens in surgical scrubs and patient surgical cleansers that health care workers and surgical patients may encounter in the perioperative period.

METHODS

DailyMed website was searched using numerous terms for surgical disinfectants. Products used for health care worker handwashing/scrubbing or patient surgical cleansing/disinfecting were included. Each product's ingredients were recorded; those found on the 2017 American Contact Dermatitis Society (ACDS) Core Allergen Series were noted from each product.

CONCLUSIONS

A total of 1940 products were identified, of which 267 were included in the analysis. A total of 66.3% contained iodine, 25.8% contained chlorhexidine digluconate, and 2.6% contained chloroxylenol. Within the group analyzed, 1586 ingredients were identified. Of these, 241 were ACDS Core Series allergens. Most products contained a single ACDS allergen. There were significant differences in allergens based on product type and active ingredient, with iodine-containing products having the fewest number of allergens. The most common ACDS allergens found were cocamide diethanolamide (22.5%), fragrance (21.7%), lanolin (19.5%), propylene glycol (6.7%), alkyl glucosides (6.0%), and sorbic acid derivatives (5.6%).

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.

Emollient treatment of atopic dermatitis: latest evidence and clinical considerations

Aim

To review current classes of emollients in the market, their clinical efficacy in atopic dermatitis (AD) and considerations for choice of an emollient.

Methods

PubMed Clinical Queries under Clinical Study Categories (with Category limited to Therapy and Scope limited to Narrow) and Systematic Reviews were used as the search engine. Keywords of ‘emollient or moisturizer’ and ‘atopic dermatitis’ were used.

Overview of findings

Using the keywords of ‘emollient’ and ‘atopic dermatitis’, there were 105 and 36 hits under Clinical Study Categories (with Category limited to Therapy and Scope limited to Narrow) and Systematic Reviews, respectively. Plant-derived products, animal products and special ingredients were discussed. Selected proprietary products were tabulated.

Conclusions

A number of proprietary emollients have undergone trials with clinical data available on PubMed-indexed journals. Most moisturizers showed some beneficial effects, but there was generally no evidence that one moisturizer is superior to another. Choosing an appropriate emollient for AD patients would improve acceptability and adherence for emollient treatment. Physician’s recommendation is the primary consideration for patients when selecting a moisturizer/emollient; therefore, doctors should provide evidence-based information about these emollients.

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.