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 Table of Contents  
Year : 2020  |  Volume : 4  |  Issue : 2  |  Page : 155-159

Changing allergen pattern in allergic contact dermatitis

Department of Dermatology, Sri Siddhartha Medical College, Tumkur, Karnataka, India

Date of Submission06-Aug-2019
Date of Decision23-Dec-2019
Date of Acceptance26-Mar-2020
Date of Web Publication18-Aug-2020

Correspondence Address:
Neethu Mary George
Sri Siddhartha Medical College, Tumkur, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/CDR.CDR_27_19

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Background: Allergic contact dermatitis (ACD), a T-cell mediated type 4 hypersensitivity reaction, occurs when skin get exposed to exogenous allergens. True incidence of ACD is difficult to estimate. Common sensitizers also vary with place, patient profile and time. With increasing complexity of human life, our skin gets exposed to a large spectrum of chemical and biological products, thereby increasing allergic sensitisation. Aim and objectives: To identify the common allergens causing allergic contact dermatitis in a tertiary health centre and to determine the clinical profile of patients presenting with the same. Settings and Design: A cross sectional study was conducted in a tertiary health centre in Tumkur. Materials and methods: Fifty patients with suspected allergic contact dermatitis were enrolled. Demographic data, clinical history, examination and patch testing with Indian standard series containing 19 allergens was done after subsidence of active eczema. Statistical analysis used: Descriptive statistics were reported using mean and standard deviation for continuous variables, number and percentage for categorical variables. The Chi-Square test was used and a 'p' value of 0.05 proportion or less was considered statistically significant. Results: Out of the 50, 35 were patch test positive. There was a slight male predominance(4:3) and majority belonged to the age group 31-50 years. The common allergens in decreasing frequency were parthenium, fragrance mix, PPD, potassium dichromate and chlorocresol. Conclusions: With changing lifestyle and urbanization, the allergens keep on varying. The clinical pattern also varies with the causative allergen/s. Such studies help to detect the common prevalent allergens in a locality and thereby avoid misdiagnosis and also in creating awareness.

Keywords: Allergens, contact dermatitis, eczema, fragrance mix, Indian standard series, Parthenium, patch testing

How to cite this article:
George NM, Gangaiah N, Thimmappa V, Potlapati A. Changing allergen pattern in allergic contact dermatitis. Clin Dermatol Rev 2020;4:155-9

How to cite this URL:
George NM, Gangaiah N, Thimmappa V, Potlapati A. Changing allergen pattern in allergic contact dermatitis. Clin Dermatol Rev [serial online] 2020 [cited 2023 Feb 5];4:155-9. Available from: https://www.cdriadvlkn.org/text.asp?2020/4/2/155/292471

  Introduction Top

Allergic contact dermatitis (ACD) is a T-cell-mediated type IV hypersensitivity reaction on the skin following contact with an exogenous antigen.[1] Patch test is the gold standard for the diagnosis of ACD,[2] and It is changed to “it should be used to exclude contact allergy in stubborn cases of eczematous diseases.”[3] With increasing complexity of human life, our skin gets exposed to a large spectrum of chemical and biological products, which keep on changing with time, thereby increasing allergic sensitization. However, true incidence of ACD in a society is difficult to estimate since its diagnosis depends on several factors, such as the demographic profile of patients, industrial development, index of suspicion of the physician, and availability of patch testing. ACD can present with manifestations adversely affecting one's physical, mental, and social well-being. The management lies in the avoidance of causative allergen without which they will have persistent or recurrent dermatitis. Patch test helps in the early diagnosis and timely intervention, thus reducing resources used and improving the quality of life of the patient considerably. The study was undertaken to determine the allergen pattern in our locality and to determine the clinical profile of patients who are patch test positive.

  Subjects and Methods Top

Fifty cases of suspected ACD who attended the outpatient section of the department of dermatology in a tertiary care hospital in Karnataka from November 2017 to November 2018 and who consented for the test were included in the study. A detailed history pertaining to the demographic data, occupation, duration of eczema, and external agents to which they are exposed day to day was taken using a questionnaire. Cutaneous examination to determine the involvement and morphology of the lesions was done. Patients with active disease, those less than 18 years of age, pregnant females, and those taking systemic steroids and antihistamines for the last 2 weeks were excluded from the study. Patients were subjected to patch testing with the Indian Standard Series from Systopic Laboratories, approved by the Contact and Occupational Dermatoses Forum of India, which contains 19 allergens and one control (Vaseline). Finn chambers with allergen in appropriate dilution were applied on the upper back mounted on a micropore tape. Day 2 and day 4 readings were taken and interpreted according to the International Contact Dermatitis Research Group grade, and only those reactions that persisted beyond day 2 were considered positive, to exclude irritant contact reaction.

  Results Top

Of the total 50 patients, with the age group between 18 and 85 years (mean 48.09 ± 14.7), 35 (70%) were found to be patch test positive.

Majority of the patch test positives belonged to the age group of 31–50 years and had slight male predominance (4:3). Majority in the study were farmers (42.9%) followed by homemakers and elderly (25.7%), shop owners (14.3%), and manual laborer/construction workers (8.6%). Duration of the symptoms for majority (42.9%) was between 6 months and 2 years, with most of them having an episodic rather than continuous course. 32 (91.4%) of them presented with pruritus and 2 (5.7%) with burning pain. Only one patient was asymptomatic. 9 (25.7%) out of total 35 patients mentioned above had a history of atopy.

Thirty-four patients (97.14%) had taken some treatment before presenting to us with ACD, the common ones being antihistamines, topical steroids, and Ayurvedic medications. Nineteen (54.3%) of ACD-positive patients showed a morphology of papules and plaques with minimal scaling followed by erythematous papules and hyperkeratotic/lichenified plaques. The distribution of the lesion is given in [Graph 1].

Allergen pattern

Thirty-five out of the total 50 patients showed positivity to either one or more of the allergens. Seventeen had single-allergen positivity while others had multiple-allergen positivity. However, the number of allergens positive in different age groups or sex was not found to be statistically significant (P = 0.289 and 1.0, respectively). The most common allergen found was Parthenium followed by fragrance mix. At least one of the suspected allergens from history and clinical examination was positive in 25 (71.4%) cases. The following allergens were found positive by patch testing [Graph 2].

In the 21 Parthenium-positive patients, males (12) were more involved than females (9). Thirty-three percent of the 21 patients had only Parthenium positive while rest of them had one or more other allergens positive along with it: cobalt sulfate (2), paraphenylene diamine (PPD) (5), fragrance mix (6), thiuram mix (3), chlorocresol (5), nickel sulfate (1), neomycin sulfate (2), paraben (2), black rubber mix (1), and potassium dichromate (1) [Figure 1]. Sunlight aggravation was present in 62%. In the total 21 patients, 90.5% gave a history of Parthenium exposure and the clinical presentation was suggestive of Parthenium dermatitis. 65% had involvement of photoexposed sites and 35% airborne sites [Figure 2].
Figure 1: Multiple allergen positivity - Parthenium, neomycin sulfate, and thiuram mix

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Figure 2: Airborne distribution of lesions in Parthenium-positive patient

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Ten out of the total 35 patients showed fragrance mix positivity; however, in none of the patients, it was suspected as the causative allergen. Only in two patients, fragrance mix alone was positive. Rest of them had other allergens positive along with fragrance mix, which included Parthenium (6), PPD (3), paraben (3), chlorocresol (3), cobalt sulfate (1), potassium dichromate (1), neomycin sulfate (1), thiuram mix (1), nitrofurazon (1), and black rubber mix (1).

Although the patch test demonstrated multiple allergens, significant allergen responsible for their symptoms was elicited using detailed history and clinical examination, which included Parthenium (17), fragrance mix (6), potassium dichromate (5), PPD (3), neomycin sulfate (1), mercaptobenzothiazole (1), nickel sulfate (1), and colophony (1). 15 (43%) people developed some side effects after application of the patch. In 11 of them, side effects appeared after day 2 reading, with itching being the predominant symptom. Twenty-six percent had itching at the site of eczema, 6% had exacerbation of the lesion, and 11% had itching at patch test site.

  Discussion Top

ACD occurs when an allergen comes into contact with the previously sensitized skin due to cell-mediated hypersensitivity or immunity. Prevalence of ACD and the allergens are found to vary in different studies. In recent years, due to urbanization and increased usage of cosmetics, the trend of ACD is rising. The allergens included in standard series vary from country to country as well in the different regions of the same country.

The study included a total of 50 patients who presented with a clinical history suggestive of ACD of whom 35 were found to be patch test positive. The rest could be having either a different diagnosis or positivity to any other allergen which is not present in the Indian Standard Series of Allergens. 71.4% of the patients were positive to at least one of the “suspected” allergens based on history, which points to the importance of a detailed present and past history, including hobbies, daily activities, and habits. Patch test positivity in our study (70%) was much higher than that obtained by Bajaj et al. (60%) and Mehta (51.33%).[4],[5]

There was a slight male predominance in the ACD-positive patients, with the major allergens in them being Parthenium, fragrance mix, and potassium dichromate.[Table 1] This male predominance was in concordance with other studies.[5],[6] This could probably be based on social and occupational factors which make them prone to get exposed to multiple allergens. This could also be dependent on the place of study, ours being a semi-urban setup with majority farmers, which could have limited women seeking medical help. Moreover, only a few among the total clinically diagnosed men and women were ready to participate in the test which required a 2-day follow-up out of financial, occupational, or social reasons.
Table 1: Sex distribution of the allergens

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Majority of patch test-positive patients belonged to 31–50 years, the working and earning age group which make them prone to get exposed to multiple allergens.[7],[8]

Fifty-one percent gave a history of sunlight aggravation which points to the importance of photopatch test in these patients. 25.7% gave a history of atopy. Defective epidermal barrier in those could be the possible reason which will help in easy entry of allergens and hence more of ACD. The role of defective barrier as an initiating event was explained by De Benedetto et al.[9]

Considering the allergen pattern, the most common allergen was Parthenium followed by fragrance mix. Nickel and potassium dichromate, though common in other studies conducted on ACD, were found in only 5.7 and 20%, respectively.

Patch testing by other studies demonstrates a gradual change in allergen pattern over years [Table 2].
Table 2: Comparison of studies to analyze the changing allergen pattern

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Parthenium being a weed is quite common in our locality, and majority of our patients being farmers could be the possible cause of a high Parthenium positivity. In patch test-proven Parthenium dermatitis patients (57%), men were more involved and majority were farmers suggesting their possible exposure to weeds at farms.

28.5% of the patients showing fragrance mix positivity were unlike any similar studies, except for a study by Mehta et al., which showed a positivity of 11.66%.[5] Fragrance mix is commonly seen in soaps, perfumes, shampoos, cosmetics, or any fragrant substance. Fragrance mix positivity was mainly seen among men (60%), farmers, and shop owners. This indirectly points to the change in lifestyle practices and quality of living and may further increase in the future. Both Parthenium and fragrance mix are known to cause sunlight aggravation, and it was in concordance with our patients who gave a history of sunlight aggravation.[15]

Patch test is a relatively safe procedure, and only 43% of our patients developed side effects following the test, majority being itching over previous existing lesions. 51.4% showed positivity to more than one allergen similar to Mehta et al. (54.83%).[5] Patients having contact dermatitis are intrinsically hyperresponsive and thus prone to develop multiple allergies as seen in various studies. The main reasons for multiple patch test reactions are nonspecific hyperreactivity, multiple primary hypersensitivities, and cross-reactions. Nonspecific hyperreactivity is the cause for multiple strong positives in a person with active dermatitis anywhere on the body; either distant body sites or a strong-positive reaction on the back induces other nonspecific false-positive reaction, which is known as “spillover,” “excited skin,” or “angry back.” Neither did any of the patients have active eczema anywhere on the body when the patch was applied nor any strong-positive allergic reactions in those with multiple allergens. Cross-reaction/cross-sensitization is the phenomenon where sensitization engendered by one compound, the primary allergen, extends to one or more other compounds, the secondary allergens, as a result of structural similarity. Multiple concomitant primary hypersensitivities to substances that are chemically unrelated can be seen in those with long duration of contact dermatitis. In this study, the two allergens commonly occurring together were Parthenium and fragrance mix, both of them have not been shown to produce cross-sensitization in the literature, and hence, it could be due to multiple concomitant sensitization. However, other allergens which we commonly found together also had evidence of possible cross-sensitivities, viz., PPD-sesquiterpene lactone[16] and PPD-paraben mix.

Based on clinical history and lesion morphology, the predominant allergens were determined, but patch test positivity to other allergens indicates that they are sensitized and they could probably get a clinical manifestation on further exposure to those. COADEX scale is a practical tool which helps to assess the clinical relevance of positive patch test results [Table 3]. Out of the total 21 Parthenium-positive and 10 fragrance mix-positive patients, 14 and 2 had current relevance, respectively.
Table 3: The COADEX scale to assess the clinical relevance

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Considering the limitations, the sample size was much lower in this study. Day 7 reading which is important in cases of metal, antibiotics, fragrance, etc., was not taken for any of the patients, and in none of the patients, a photopatch test could be done which would have proven the photoaggravation.

In this era of urbanization and cosmetics, it is necessary to patch test every suspected patients as the clinical appearance can be varied based on allergens. Such studies at large scale will help in establishing the prevalence of particular allergen in that area and may be useful from community point of view for spreading awareness. It helps to assess the relevance of the “standard series” and helps to update the same. Moreover, it also helps us not to miss the diagnosis as the clinical manifestation can also vary with changing allergens. Those patients who are allergic should be counseled regarding the occupational and lifestyle modifications for avoidance of allergen and the need for the same. In cases where there is unavoidable exposure, they must be advised regarding protective measures and when possible a change in occupation if the symptoms are not getting relieved. Moreover, it helps in saving healthcare resources and financial burden for the patient.

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Conflicts of interest

There are no conflicts of interest.

  References Top

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Wilkinson M, Orton D. Allergic contact dermatitis. In: Barker J, Bleiker T, Chalmers R, Creamer D, Griffith C, editors. Rooks Textbook of Dermatology. UK: Wiely-Blackwell 2016. p. 128.64.  Back to cited text no. 3
Bajaj AK, Saraswat A, Mukhija G, Rastogi S, Yadav S. Patch testing experience with 1000 patients. Indian J Dermatol Venereol Leprol 2007;73:313-8.  Back to cited text no. 4
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  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3]


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