|Year : 2022 | Volume
| Issue : 1 | Page : 32-37
Correlation of Contact Sensitization to Common Allergens with Disease Severity in Discoid Eczema: An Analytical Observational Study
Aishwarya Raheja1, Ajay Kumar1, Avinash Jadhav1, Mahendra Singh Deora1, Dipti Mathias1, Prachi Agrawal2, Rahul Ranpariya1
1 Department of Dermatology, Dr DY Patil Medical College, Hospital and Research Centre, Pune, Maharashtra, India
2 Department of Dermatology, Ravindra Nath Tagore Medical College, Udaipur, Rajasthan, India
|Date of Submission||26-Jan-2021|
|Date of Decision||30-May-2021|
|Date of Acceptance||11-Jul-2021|
|Date of Web Publication||25-Feb-2022|
U1/7 AWHO Enclave, Hadapsar, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: Discoid eczema, defined by well-demarcated round or oval plaques, is a form of endogenous eczema in which the role of contact allergens is not clearly established. Objectives: This study aims to assess the role of contact allergens in discoid eczema by patch testing, determine clinical relevance and correlate patch test reactivity with the severity of disease and atopy. Materials and Methods: Sample characteristics including occupation, atopic diathesis and clinical details were recorded. Disease severity was assessed by the Eczema and Area Severity Index (EASI) and patch testing carried out with the Indian Standard Battery. Relevance of patch tests was determined by a history of exposure and patch testing with patients' own materials. Results: Fifty-one patients having a median age of 38 years were enrolled out of which 31 (60.8%) were male. Patch tests were reactive in 25 (49%) patients, common sensitizers being fragrance mix in 9 (31.0%), potassium dichromate in 4 (13.8%), paraphenylenediamine in 4 (13.8%), and nickel in 3 (10.3%) cases. Clinical relevance was established in 11 (37.9%) cases. In patch test reactive patients the mean EASI score was 3.4 as compared with 4.5 in nonreactors. Patch tests were positive in 3 (25%) atopic as compared with 22 (56.4%) nonatopic patients. Conclusion: Contact sensitization to common allergens may not contribute to disease severity in discoid eczema. Patch test reactivity is low in atopic as compared with nonatopic patients with discoid eczema.
Keywords: Atopic diathesis, clinical relevance of patch tests, discoid eczema, Eczema and area Severity Index, Indian standard battery
|How to cite this article:|
Raheja A, Kumar A, Jadhav A, Deora MS, Mathias D, Agrawal P, Ranpariya R. Correlation of Contact Sensitization to Common Allergens with Disease Severity in Discoid Eczema: An Analytical Observational Study. Clin Dermatol Rev 2022;6:32-7
|How to cite this URL:|
Raheja A, Kumar A, Jadhav A, Deora MS, Mathias D, Agrawal P, Ranpariya R. Correlation of Contact Sensitization to Common Allergens with Disease Severity in Discoid Eczema: An Analytical Observational Study. Clin Dermatol Rev [serial online] 2022 [cited 2022 May 22];6:32-7. Available from: https://www.cdriadvlkn.org/text.asp?2022/6/1/32/338595
| Introduction|| |
Discoid eczema, also known as nummular eczema, characterized by round or oval plaques with clearly demarcated edges is considered to be a morphological pattern and not a disease per se. It is classified as a form of endogenous eczema. It has a multifactorial etiology in which contact sensitivity may play a role.,
Although initially described by Rayer, the term “nummular eczema” was coined by Devergie in the year 1857., Discoid eczema may be associated with an atopic diathesis, staphylococcal colonization and normal immunoglobulin E levels., Low environmental humidity may predispose to an exacerbation of eczema.
The primary objective of our study was to evaluate the role of contact allergens in discoid eczema by assessing the clinical relevance of patch testing with the Indian Standard Battery while the secondary objectives were to correlate patch test reactivity with disease severity and with atopy.
Various studies have been carried out to evaluate the role of contact allergens in discoid eczema by patch testing with standard series antigens.,,,,,, We carried out patch testing using the Indian Standard Battery approved by the Contact and Occupational Dermatoses Forum of India. The clinical relevance of positive patch tests in discoid eczema has been evaluated in various studies., In the present study we determined the clinical relevance of patch tests on the basis of a history of exposure to allergens as well as by patch testing with materials used by the patients.
Previous studies have not correlated the severity of discoid eczema with patch test reactivity. In the present study, we compared the severity of disease (Eczema and Area Severity Index [EASI] score) in patch test reactive with that in patch test nonreactive patients. We also analyzed patch test reactivity in atopic as compared with nonatopic patients of discoid eczema.
| Materials and Methods|| |
Fifty-one clinically diagnosed patients of discoid eczema were enrolled after obtaining written informed consent and approval of the institutional ethics committee. Those above the age of 18 years with discoid or oval eczematous plaques with clearly demarcated edges were included in the study. Those with dermatophytosis or candidiasis (confirmed by 10% KOH mount were excluded from the study. Pregnant or lactating mothers, those with severe active dermatitis or dermatitis upper back, those with immunodeficiency and those on systemic corticosteroid therapy were also excluded.
An observational analytical study was carried out to assess the association between discoid eczema and contact sensitization and correlate patch test reactivity with disease severity as well as atopy. Determining an estimate of patch test reactivity among the study population with an approximately 10% margin of error required a minimal sample size of 50. Statistical analysis was carried out using WinPepi software.
The personal particulars including occupation, personal and family history of atopy, duration of disease, and household or occupational contact with allergens were noted. The morphology, site and distribution of lesions were recorded and disease severity (EASI score) assessed in all cases.
Patch testing was carried out using a set of 20 common antigens from the Indian Standard Battery. The allergens as well as aluminum chambers mounted on hypoallergenic tape were supplied by Systopic India, Ltd. The skin of the upper back was gently cleaned with ethanol, allowed to dry and patches applied for 48 h. Readings were taken 1 h after removal of patches at the end of 48 h (D2) and 96 h (D4). The reactions were graded according to the International Contact Dermatitis Research Group criteria. Since false-positive irritant reactions may occur on D2, only morphologically positive patch test reactions (+, ++ or +++) observed on day D4 were considered.
Positive patch tests are clinically relevant if the pattern, anatomical sites and the course of eczematous dermatitis correlate with existing exposure to the sensitizer. A positive patch test may have current relevance if it correlates with the present eczematous dermatitis or past relevance if it correlates with a past dermatitis. A detailed temporal history of exposure to materials associated with each allergen was obtained from the patients. Only current relevance was taken into account. Clinical relevance is (i) Possible: when the allergen is associated with a material used by the patient; (ii) Probable: when the patient tests positive not only to the allergen but also to his own material (iii) Likely: recurrence of dermatitis occurs on reexposure to the material.
The clinical relevance of patch tests was determined not only on the basis of a history of exposure to allergens but also by direct patch testing with materials used by the patients. The conventional method was used for direct patch testing with cosmetic creams, emollients and talcum powders “as is,” soap bars in 1% concentration in aqua and hair dyes in 1% concentration in petrolatum. The semi-open method was used for patch testing with materials with irritant properties including shampoos, balms, liquid cleansing detergents and aqueous cutting oils in which a small quantity of the liquid was applied on 1 cm2 area of skin with a cotton-tipped earbud, allowed to dry and covered with permeable tape. Rubber from footwear, latex gloves or tyres was patch tested by the semi-open method by placing a small piece on the skin and covering it with permeable tape. Cement which has a high irritant potential was also patch tested by the semi-open method. The readings of semi-open patch tests were taken on D2 and D4 in the conventional manner.
| Results|| |
Out of 51 patients, 31 (60.8%) were male and their age ranged from 22 to 58 years with a median age of 38 years. Twelve (23.5%) had an atopic diathesis. Their occupations included labourers-14; homemakers-12; office workers-10; factory workers-8; farm workers-5; and others-2. The duration of illness ranged from 4 months to 15 years with a median duration of 2 years. The sites of lesions were the lower limbs in 26 (51.0%), upper limbs in 15 (29.4%), hands in 4 (7.8%), neck in 4 (7.8%), and trunk in 2 (3.9%) patients. The sample characteristics of patch test nonreactive and reactive patients are detailed in [Table 1] and [Table 2], respectively.
|Table 1: Sample characteristics and disease severity in patch test negative patients|
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|Table 2: Sample characteristics and disease severity in patch test reactive patients|
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Patch tests to one or more standard series allergens were positive in 25 (49.0%) patients [Figure 1]. Common sensitisers were fragrance mix in 9 (31.0%), potassium dichromate in 4 (13.8%), paraphenylenediamine (PPD) in 4 (13.8%), nickel in 3 (10.3%), thiuram mix in 3 (10.3%), parthenium in 2 (6.9%), wood alcohol in 2 (6.9%), and colophony in 2 (6.9%) cases [Table 2].
|Figure 1: A positive patch test reaction (+) to fragrance mix on D4 in a 31-year old housewife|
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Clinical relevance of positive patch tests was affirmed in 11 (37.9%) cases to materials associated with fragrance mix allergens in 7 (63.6%), potassium dichromate in 3 (27.3%), and nickel in 1 (9.1%) [Table 1]. The disease severity EASI score ranged from 1 to 12. The mean EASI score of 3.4 in patch test reactors [Table 1] was marginally less than the score of 4.5 in patch test nonreactors [Table 2]. However, these results are not statistically significant (t = 1.66; d.f = 49; P = 0.103) [Table 3].
Among atopic patients of discoid eczema 3 (25%) were patch test reactive while 9 (75%) were nonreactive whereas among nonatopic patients 22 (56.4%) were patch test reactive while 17 (43.6%) were nonreactive. Higher patch test reactivity of 56.4% in nonatopic as compared to 25% in atopic patients is not statistically significant (χ2 = 2.475; d.f = 1; P = 0.116) [Table 4].
| Discussion|| |
Males are affected with discoid eczema more frequently and at a later age than females and in the present study 60.8% of patients were male. This is consistent with reports from South Korea, southern Italy and northern India,,, but at variance with a study carried out in Thailand in which only 33.3% were male. In our study, the median age of males was 40 years and females 35 years.
The variants of discoid eczema include the dry type, the exudative type, discoid eczema of hands and exudative discoid and lichenoid chronic dermatitis [Figure 2]., In the present study, the severity of disease varied from an EASI score of 1–12, the highest score of 12 being observed in a homemaker with exudative discoid and lichenoid chronic dermatitis (Sulzberger Garbe syndrome), a form of discoid eczema that is resistant to therapy.
|Figure 2: The types of discoid eczema included (a) the dry type, (b) the exudative type, (c) discoid eczema of hands and (d) exudative discoid and lichenoid chronic dermatitis|
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In our study patch tests were positive in 49.0% of patients to one or more antigens. A patient who developed the “angry back phenomenon” with a nonspecific reaction to all the test antigens [Figure 3] was found to be patch test reactive to PPD on repeat patch testing after 4 weeks. The most common sensitisers were fragrance mix in 31%, potassium dichromate in 13.8%, PPD in 13.8% and nickel in 10.3% of cases. Patch test reactivity was found to be consistent with the occupational profile and thus reactivity to fragrance mix was more frequent among homemakers and reactivity to potassium dichromate among labourers.
|Figure 3: The “angry back phenomenon” with a nonspecific reaction to all the test antigens. The patient was found to be patch test positive to paraphenylenediamine when patch tests were repeated after 4 weeks|
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High patch test reactivity to fragrance mix in our study is at variance with a study carried out in southern Italy in which only 1% of patients of discoid eczema were patch test reactive to fragrance mix. This may be attributed to an amendment to the Cosmetic Directive of the European Union passed in 2003 making it mandatory to mention the word perfume in the ingredients of all cosmetic products and label any out of 26 fragrance chemicals if present above 10 ppm in leave-on products and above 100 ppm in rinse-off products.
The clinical relevance of patch test reactivity was confirmed not only by the of history of exposure to allergens but also by direct patch testing with materials used by the patients including cosmetic creams, hair dyes, hair oils, talcum powder, soap bars, balm, cutting oils, rubber, and cement. Clinical relevance was established in 37.9% of positive patch tests to the standard series antigens in our study. Out of the clinically relevant patch test reactions, 63.6% had relevance to fragrance mix, 27.3% to potassium dichromate and 9.1% to nickel.
Various studies have mentioned that contact allergens contribute to the severity of disease in discoid eczema.,,,, Our observations using a disease severity index are at variance with the above reports. In patch test reactive patients the disease severity (mean EASI) score of 3.4 was found to be marginally lower than the score of 4.5 in nonreactors. In other words, contact allergens may not contribute to disease severity. Due to the small sample size these results are not statistically significant (t = 1.66; d.f = 49; P = 0.103).
An atopic diathesis may be defined as a genetic predisposition to develop asthma, allergic rhinitis or atopic dermatitis. These atopic diseases in which environmental factors notably exposure to allergens may play a role, are associated with raised IgE levels. In the present study, only 25% of atopic as compared with 56.4% of nonatopic patients with discoid eczema were found to be patch test reactive. These results are not statistically significant due to the small sample size (χ2 = 2.475; d.f = 1; P = 0.116). In atopic patients thymic stromal lymphopoietin secreted by epithelial cells stimulates resident skin dendritic cells by expression of OX40 to migrate to draining lymph nodes and induce differentiation of naive CD4+ T cells into the Th2 phenotype., On antigen presentation, these primed CD4+ T cells may be refractory to further differentiation into memory T cells accounting for low patch test reactivity among atopic patients.
To conclude contact sensitisation to common allergens does not contribute to disease severity and may not play a causal role in discoid eczema. Low contact sensitisation occurs in atopic as compared with nonatopic patients with discoid eczema.
The limitation of our study is the small sample size and our results require further validation.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]