Recognizing and Managing Allergic Contact Dermatitis: Focus on Major Allergens

Patch testing is the reference standard for the diagnosis of allergic contact dermatitis. Identification and avoidance of culprit allergens are essential in the treatment of this disease. Each year, new allergens are identified as emerging or important. The authors discuss allergens that are common, enduring, emergent, incompletely recognized, and controversial for the practicing allergist and dermatologist. This Clinical Management Review will encompass a review of fragrances, preservatives, rubber, acrylates, metals, and medications; their common sources of exposure; controversies in diagnosis and patch testing; management and how to avoid those allergens. This review will also include practical aspects of diagnosis and management and will provide resources that can be used as guidance for physicians and patients on nickel, methylchloroisothiazolinone/methylisothiazolinone, and fragrance, the most common allergens positive on patch testing.

Henna Tattoo: From Cosmetic Purposes to Dermatological Reactions

Introduction

Henna, commonly used as a hair dye, is also used for temporary tattoos. It is commonly mixed with para-phenylenediamine (PPD) to enhance color intensity, which may induce cutaneous sensitization.

Aim

This study aimed to describe the clinicodemographic features of patients with dermatological reactions to henna tattoos.

Materials and Methods

This cross-sectional study, included patients with dermatological reactions to henna tattoos. All the patients were subjected to entire medical history including clinicodemographic data and general and dermatological examinations.

Results

This study included 17 female patients with a mean age of 26.88 ± 6.6 years. Of these 17 patients; 41.2% were suburban residents, 58.8% were housewives, 70.6% were married, and 47.1% were middle socioeconomic class and 53% had type IV Fitzpatrick skin. All used black color and commercial henna for cosmetic purposes, 41.2% used market henna, and 35.3% used coiffeur henna. Many (70.6%) had localized reactions with 23.5% presenting with reaction of hands, 64.7% had acute eczematous reactions, and all had a progressive course. The mean duration of the reaction was 6.76 ± 2.6 days. The mean latency time of the reaction was 2.7 ± 0.85 days.

Conclusion

This study concluded that public awareness of possible cutaneous reactions to henna tattoos should be increased. The health authority legislation should control the use of black henna to minimize the consequences.

Epicutaneous Patch Testing in Type IV Allergy Diagnostics: State of the Art and Best Practice Recommendations

This chapter summarises all relevant aspects of patch testing, closely following recommendations outlined in a recent European, and a German S3 guideline on diagnostic patch testing with contact allergens and medicinal products (drugs). Patch testing is indicated in patients suspected of suffering, or having been suffering, from delayed-type hypersensitivity leading to allergic contact dermatitis or other skin and mucosal diseases. Sections of this chapter include detailed indications, reasons for possibly postponing the test, considerations on choosing haptens (contact allergens) to test, various aspects of the application of patch test allergen preparations (storage, dosing) and of testing with individual materials provided by the patients. Special aspects of patch testing in cutaneous adverse drug reactions, children, or occupational contact dermatitis are outlined. Supplemental test methods, notably the repeated open application test, are briefly described. Finally, the final evaluation in terms of assessment of clinical relevance of reactions and patient counselling are outlined.

Contact Dermatitis: Overcoming Challenges of Specific Patients, Deciphering the Results and Reaching a Correct Diagnosis

Skin lesions caused by allergic contact dermatitis are an important occupational and environmental disease. Patch testing is the gold-standard procedure used to diagnose allergic contact dermatitis.The present chapter summarizes aspects of patch testing for the diagnosis of contact allergy: important working definitions, relevance of treating contact dermatitis, materials, technique, test result and interpretation, and special consideration regarding individual factors which influence the patch test outcome or necessitate special attention.Performing and interpreting patch tests requires know-how. Knowing how to perform them and the particularities of specific cases is essential to correctly interpret the results. A correct evaluation and diagnosis will significantly impact the natural history of the disease and significantly improve the quality of life of the patient.

S3 Guidelines: Epicutaneous patch testing with contact allergens and drugs - Short version, Part 2

Epicutaneous patch testing is the diagnostic standard for the detection of allergic contact dermatitis. The present guidelines are aimed at residents and board-certified physicians in the fields of dermatology and allergology as well as other medical specialties involved in establishing the indication for patch testing and its execution in patients with contact dermatitis and other forms of delayed-type hypersensitivity. The target audience also includes other health care providers and insurance funds. Based on a systematic literature search and a formal consensus process (S3), the guidelines were developed by dermatologists in collaboration with pediatricians, occupational medicine physicians, nursing staff as well as patient representatives. The systematic methodological approach and appraisal of evidence upon which the recommendations are based are outlined in a separate method report that also contains evidence tables. The guidelines address general aspects of patch testing as well as medicolegal issues. The recommendations given relate to topics such as the indication for patch testing, informed patient consent, as well as the choice of test substances, test chambers and test site, duration of exposure, reading times and interpretation of test reactions. Furthermore, recommendations are provided with respect to endogenous and exogenous factors, specific patient groups (children, pregnant women, immunosuppressed individuals) as well as possible risks and adverse events associated with patch testing using contact allergens.

Practice Patterns of Dermatologists in the Pediatric Contact Dermatitis Registry

BACKGROUND/OBJECTIVES

U.S. adults and children are equally likely to have allergic contact dermatitis. Historically the narrow geographic location of data-reporting providers has quantitatively and qualitatively limited the pediatric contact dermatitis data. The Pediatric Contact Dermatitis Registry was used to evaluate self-identified pediatric patch test providers within the United States with regard to demographic characteristics, geographic location, and practice patterns.

METHODS

A wide range of U.S. providers were invited to join the registry by completing a secure online 11-question registration survey.

RESULTS

There were 252 respondents from 50 states and the District of Columbia; 28.6% were pediatric dermatologists and members of the Society for Pediatric Dermatology (SPD), and 38% were members of the American Contact Dermatitis Society. The cumulative range of pediatric patch-test evaluations performed each year was 1,726 to 4,613 children. SPD members had a significantly greater likelihood of performing a commercially available patch test (odds ratio 7.14 [95% confidence interval 5.11, 9.97], p < .001) than those who were not SPD members. SPD members also had significantly lower odds of performing North American Contact Dermatitis Group standard tests than nonmembers.

CONCLUSIONS

The frequency of patch test evaluations in children is significantly underreported. This study provides insight into the practice patterns of various providers who are patch testing children and makes recommendations for evidence-based modifications regarding these practices. Limitations of the study include survey responder selection bias and small sample size.

Temporary Black Henna Tattoos and Sensitization to para-Phenylenediamine (PPD): Two Paediatric Case Reports and a Review of the Literature

Background: The use of temporary henna tattoos has increased dramatically in recent years, especially in children and adolescents. To obtain a darker colour and prolong the life of the tattoo, red henna, a plant-derived substance, is typically added to para-phenylenediamine (PPD). The mixture is called temporary black henna tattoo (TBHT). Because of its molecular characteristics, PPD can induce skin sensitization that may cause various clinical manifestations with successive exposures, among which the most common is allergic contact dermatitis (ACD). This report describes two paediatric cases of PPD sensitization and ACD after the exposure to TBHT and summarizes the literature on this emerging clinical problem. Case Presentation: We describe two cases of childhood-onset ACD that occurred 2 and 10 days, respectively, after the application of a TBHT during the summer holidays. Patch tests showed an evident positive response to 1% PPD in both cases. Sensitization to PPD occurred in the first case because a previous henna tattoo did not result in overt symptoms; in the second case, the reaction occurred after the same tattoo was retouched. In both cases, hypopigmentation persisted and both the patients and their families were advised to avoid further contact with PPD-containing materials and substances that could lead to cross-reactions. Conclusions: Sensitization to PPD is a growing phenomenon in children. The most common cause appears to be exposure to TBHT in which PPD might be present at unknown or high concentrations. Once sensitization occurs, patients may experience severe clinical symptoms which can present with a persistent hypopigmentation when they are re-exposed to substances that contain or cross-react with PPD. Given the widespread use of PPD, TBHT could adversely affect the daily life of paediatric patients; thus, for this reason, this practice as a fashion accessory must be discouraged. In addition, it is extremely important to provide scientific information on the risks of TBHT to consumers, especially to adolescents and to the parents of younger children to prevent PPD sensitization.

Patch-test results in children and adolescents: systematic review of a 15-year period

The number of studies on patch-test results in children and adolescents has gradually increased in recent years, thus stimulating reviews. This paper is a systematic review of a 15-year period devoted to studying the issue. Variations pertaining to the number and age groups of tested children and/or adolescents, the number of subjects with atopy/atopic dermatitis history, the quantity, type and concentrations of the tested substances, the test technique and type of data regarding clinical relevance, must all be considered in evaluating these studies, as they make it harder to formulate conclusions. The most common allergens in children were nickel, thimerosal, cobalt, fragrance, lanolin and neomycin. In adolescents, they were nickel, thimerosal, cobalt, fragrance, potassium dichromate, and Myroxylon pereirae. Knowledge of this matter aids health professionals in planning preventive programs aimed at improving children's quality of life and ensuring that their future prospects are not undermined.

European Society of Contact Dermatitis guideline for diagnostic patch testing - recommendations on best practice

The present guideline summarizes all aspects of patch testing for the diagnosis of contact allergy in patients suspected of suffering, or having been suffering, from allergic contact dermatitis or other delayed-type hypersensitivity skin and mucosal conditions. Sections with brief descriptions and discussions of different pertinent topics are followed by a highlighted short practical recommendation. Topics comprise, after an introduction with important definitions, materials, technique, modifications of epicutaneous testing, individual factors influencing the patch test outcome or necessitating special considerations, children, patients with occupational contact dermatitis and drug eruptions as special groups, patch testing of materials brought in by the patient, adverse effects of patch testing, and the final evaluation and patient counselling based on this judgement. Finally, short reference is made to aspects of (continuing) medical education and to electronic collection of data for epidemiological surveillance.

Side-effects of henna and semi-permanent 'black henna' tattoos: a full review

Henna, the dried and powdered leaf of Lawsonia inermis, is widely used as a dye for the skin, hair, and nails, and as an expression of body art, especially in Islamic and Hindu cultures. As it stains the skin reddish-brown, it is also called red henna. Black henna is the combination of red henna with p-phenylenediamine (PPD), and is used for temporary 'black henna tattoos'. This article provides a full review of the side-effects of topical application of red and black henna, both cutaneous (allergic and non-allergic) and systemic. Red henna appears to be generally safe, with rare instances of contact allergy and type I hypersensitivity reactions. In children with glucose-6-phosphate dehydrogenase deficiency, topical application of henna may cause life-threatening haemolysis. Black henna tattoos will induce contact allergy to its ingredient PPD at an estimated frequency of 2.5%. Once sensitized, the patients may experience allergic contact dermatitis from the use of hair dyes containing PPD. There are often cross-reactions to other hair dyes, dyes used in textiles, local anaesthetics, and rubber chemicals. The sensitization of children to PPD may have important consequences for health and later career prospects. Systemic toxicity of black henna has been reported in certain African countries.

Severe allergic reactions to para-phenylenediamine in children and adolescents: should the patch test concentration of PPD be changed?

BACKGROUND

Semipermanent henna tattoos containing para-phenylenediamine (PPD) are a well-known cause of severe contact dermatitis, mainly in children. Another relevant exposure source to PPD are hair dyes, which are increasingly used by children and have also been reported to cause intense facial and scalp dermatitis. German patch test guidelines for children recommend that PPD should only be tested in patients who have had a henna tattoo, and then at a reduced concentration of PPD 0.5 % for 24 hours.

PATIENTS AND METHODS

We report on patch test results in four patients, three children and one adolescent, with a history of contact dermatitis to henna tattoos or hair dye. We used the recommended or even lower patch test concentrations of PPD with 24-hours exposure in all patients.

RESULTS AND CONCLUSION

All patients showed very strong patch test reactions to PPD and cross-reactions to related compounds even after dilution of PPD to as low as 0.05 %. Therefore, we suggest that in children with a history of allergic reactions to this compound, a titration test should be performed beginning at a concentration of maximal 0.05 %. This procedure has also been proposed previously based on a larger cases series in adults.