Hyposensitization to poison ivy after working in a cashew nut shell oil processing factory

Plant Associated Irritant & Allergic Contact Dermatitis (Phytodermatitis)

With more than 350,000 plant species recognized and new species continually being identified, it is not surprising that humans contact plants or plant-containing products daily. The nearly endless list of potential exposures leaves us with a challenging task when attempting to categorize and study potential plant-related irritants and allergens. This article focused on laying a sound framework for understanding some of the more pertinent potential irritants and allergens.

Effects of diet on skin sensitization by nickel, poison ivy, and sesquiterpene lactones

Skin contact or exposure to sensitizers often occurs as a consequence of occupational exposures (e.g. poison ivy in forestry), wearing jewelry (e.g. nickel), or use of cosmetics (e.g. fragrances). However, many of the known skin sensitizers or their chemical variants are also consumed orally through foods or other sources. Since oral exposure to antigenic substances can lead to tolerance, consumption of sensitizers may impact the development and potency of skin sensitization, especially if the sensitizer is consumed early in life, prior to the first skin contact. To address this issue, we have reviewed human clinical and epidemiological literature relevant to this subject and evaluated whether early oral exposures to relevant sensitizers, or their chemical variants, are associated with reduced prevalence of skin sensitization to three main allergic sensitizers - nickel, urushiols of poison ivy, and sesquiterpene lactones of chrysanthemum and other plants.

Low patch test reactivity to nickel in unselected adolescents tested repeatedly with nickel in infancy

BACKGROUND

It is questionable how repeated patch tests with nickel sulfate in infancy affect nickel patch test reactivity at a later age.

METHODS

The Danish Allergy Research Center (DARC) cohort encompasses 562 infants invited to a clinical examination including patch tests with nickel sulfate six times during the first 36 months of life. At the follow-up investigation at 14 years of age (2013-2014), participants were offered re-patch tests with nickel sulfate. The Odense Adolescence Cohort Study TOACS cohort encompasses 1501 schoolchildren evaluated for the first time at 14 years of age (1995-1996) including clinical examination and nickel sulfate patch tests. The prevalence of nickel sensitization in the DARC cohort was compared to the prevalence in the TOACS cohort at 14 years of age.

RESULTS

Nickel sulfate sensitization was found in 1.2% of the participants from the DARC cohort tested repeatedly with nickel sulfate in early childhood and retested at 14 years of age compared to 8.6% of the participants from the TOACS cohort patch-tested for the first time at 14 years of age using the same patch test system and test concentration.

CONCLUSION

The significant difference in nickel patch test reactivity comparing the two cohorts may reflect an immunologic effect or the effect of nickel regulation.

Rhus (Toxicodendron) dermatitis

This article reviews the current fund of knowledge on poison ivy, poison oak, and poison sumac dermatitis. It is intended as a global summary to provide the primary care provider with the required information and sources for more esoteric academic pursuits. Toxicodendron characteristics, morphology, and biology are reviewed. The overall medical impact is delineated as well as the clinical manifestations, pathophysiology, prevention, and treatment. Historical perspectives are mentioned throughout, as are future trends in research.

A study of dermatitis in the lacquerware industry

Contact dermatitis from lacquer has been documented. The causative agent is a resin from a lacquer tree that can induce either irritation or sensitization. Thai and Japanese lacquer trees are 2 distinct species but are both members of the Anacardiaceae family. We report 3 cases of contact dermatitis from Thai lacquer resin. Observation and study of the lacquer plantation and working process at the factory were made to elucidate the aetiology of the dermatitis.

Technical and ethical problems associated with patch testing

When relevant allergens are identified by patch testing, and patients can avoid them in their environment, improvement of dermatitis is the rule. Some forms of chronic dermatitis may not clear completely, but patients are usually satisfied with modification of their previously more severe problem. In 1981 when asked what he felt were the five most important advances in clinical dermatology during the 20th century, Dr. Marion B. Sulzburger, an icon in American dermatology, said that, "The increased use and usefulness of the patch test and the international standardization of test concentrations and methods" was number one. Those of us who are enthusiastic patch testers and fascinated by the evaluation of patients with irritant and allergic contact dermatitis would agree. It is a thrilling clinical experience to be able to tell a machinist that he need not stop his lifelong occupation, but instead will do fine if he will simply avoid the waterless hand cleanser he has been using which is preserved with glutaraldehyde. The woman whose facial dermatitis has embarrassed her for years and clears when she stops using the Quaternium-15 preserved moisturizer that you have identified in your patch testing is grateful to you forever, and again happy in her own life. In 1991, my research assistants, Patricia Norris and Mary Lou Belozer, and I studied 30 university hospital workers who answered our advertisement asking for individuals who believed they were troubled by their rubber gloves (unreported study). By evaluating these people through history, physical examination, and patch testing, we were able to prove glove relatedness in 14 of them. Nine of the 14 had contact urticaria to latex, and only 5 had allergic contact dermatitis to rubber glove ingredients. Fifteen of our patients had irritant dermatitis. In this study, none of the patients with allergic contact dermatitis to glove ingredients had contact urticaria. However, since that time, we have observed a number of patients who had both forms of allergic reaction. Three of our patients who presented with nummular (patchy) hand dermatitis also had contact urticaria to latex, but no positive patch tests. With latex glove avoidance, their dermatitis resolved; an example of how scratching urticaria can eventuate in longer lasting dermatitis in some people ("the itch that rashes"). The patients presented to their dermatologist with dermatitis, but their true initiating event was urticaria which lasted only hours. The gratifying part of this study was that patch testing and contact urticaria testing allowed us to discover the 5 patients with allergic contact dermatitis and the 9 patients with contact urticaria who could benefit from glove alternatives. We were also able to assure patients in the remainder of the group that their hand eczema was not glove induced, but rather was related to their wet work. In most instances, therapeutic intervention helped, but in several cases job changes were required. Patch testing, when done properly, produces exciting results. When done improperly, it confuses and misleads patients and results in embarrassment to physicians who cannot properly interpret their results. Should a physician choose to include patch testing in his or her evaluation of patients with contact dermatitis it is essential, in my view, that he or she have highly developed skills in the diagnosis and treatment of skin diseases, and that these physicians be elaborately trained in the techniques of application and the methods of interpretation of patch tests.

Loss of contact sensitization evaluated by laser Doppler blood flowmetry and transepidermal water loss measurement

Allergic contact dermatitis, which is mediated by activated T cells through a Type IV reaction, is usually believed to persist throughout life. There have been several reports of spontaneous loss of sensitization, e.g., loss of previous patch test reaction or loss of allergic contact dermatitis withal continuous exposure to the allergens. However, these have been well quantified. The aim of this study was to confirm the development of desensitization or hyposensitization with the aid of objective measurements. A total of 18 patients with alopecia areata, who received 4 months diphenylcyclopropenone (DPCP) contact immunotherapy, were patch tested and the responses were measured by laser Doppler blood flowmetry (LDF) and transepidermal water loss (TEWL). Patch tests were performed 2X, before and after 4 months of immunotherapy. To determine whether local desensitization developed, we compared change of DPCP concentrations producing mild contact dermatitis on the scalp. Our results showed that systemic and local hyposensitization occurred in human subjects by weekly applications of low concentrations of DPCP for 4 months. LDF seems to be more correlated with visual scores than TEWL measurement.

Hyposensitization in nickel allergic contact dermatitis: clinical and immunologic monitoring

BACKGROUND

In allergic contact dermatitis (ACD) previously sensitized T cells cause skin damage. If an ubiquitous allergen such as nickel is involved, no effective treatment is available. Down-regulation of this allergic response has been described after antigen presentation in the absence of adequate costimulatory signals. UV exposure can enhance such hyposensitization.

OBJECTIVE

The aim of this study was to establish the capability of a hyposensitization procedure to induce antigen-specific tolerance.

METHODS

Twenty-one patients with nickel ACD were randomly assigned to either a hyposensitized or control group. A schedule consisting of UVB treatment and subcutaneous nickel sulfate administration (hyposensitization) or UVB only (control) was applied. During the ensuing 2 years, several clinical and immunologic features were monitored.

RESULTS

During UVB treatment we observed a significant clinical improvement in both groups that persisted in the hyposensitized group. Except for increased slope variances of specific lymphocyte proliferation in time, no clear changes were seen in the immunologic findings.

CONCLUSION

Despite significant clinical improvement induced by UVB, hyposensitization did not induce significant changes in the immunologic findings in patients with nickel ACD.

Hyposensitization to urushiol among Japanese lacquer craftsmen: results of patch tests on students learning the art of lacquerware

8 subjects learning the art of lacquerware were patch tested to urushiol before and after contact with lacquer, in order to document whether hyposensitization to urushiol occurred among Japanese lacquer craftsmen. Simultaneously, we performed patch tests on 2 urushiol-sensitized controls who had no contact with lacquer during the investigation. Lacquer is made from the sap of the Japanese lacquer tree and raw lacquer is composed of 60-65% urushiol and its oligomer. 5 of the 8 subjects showed positive reactions to urushiol 1 month after their first contact. They became negative or less positive after prolonged (9 or 10 months) exposure to lacquer. As reactions to urushiol decreased, dermatitis became less severe. Controls showed consistently high reactions. However, 1 subject showed persistently strong reactions to urushiol. Unlike the other 7 subjects, he was previously sensitized to urushiol before the first contact with lacquer. The remaining 2 subjects showed no reaction throughout our investigation. These results strongly suggest that hyposensitization to urushiol does occur among Japanese lacquer craftsmen.