Patch test results in children and adolescents. Study from the Santa Casa de Belo Horizonte Dermatology Clinic,Brazil, from 2003 to 2010

BACKGROUND

Patch testing is an efficient method to identify the allergen responsible for allergic contact dermatitis.

OBJECTIVE

To evaluate the results of patch tests in children and adolescents comparing these two age groups'' results.

METHODS

Cross-sectional study to assess patch test results of 125 children and adolescents aged 1-19 years, with suspected allergic contact dermatitis, in a dermatology clinic in Brazil. Two Brazilian standardized series were used.

RESULTS

Seventy four (59.2%) patients had "at least one positive reaction" to the patch test. Among these positive tests, 77.0% were deemed relevant. The most frequent allergens were nickel (36.8%), thimerosal (18.4%), tosylamide formaldehyde resin (6.8%), neomycin (6.4%), cobalt (4.0%) and fragrance mix I (4.0%). The most frequent positive tests came from adolescents (p=0.0014) and females (p=0.0002). There was no relevant statistical difference concerning contact sensitizations among patients with or without atopic history. However, there were significant differences regarding sensitization to nickel (p=0.029) and thimerosal (p=0.042) between the two age groups under study, while adolescents were the most affected.

CONCLUSION

Nickel and fragrances were the only positive (and relevant) allergens in children. Nickel and tosylamide formaldehyde resin were the most frequent and relevant allergens among adolescents.     

Cytokine detection for the diagnosis of chromium allergy

BACKGROUND

Patch testing remains the gold standard method for the identification of the etiologic agent of allergic contact dermatitis. However, it is a subjective, time-consuming exam whose technique demands special care and which presents some contraindications, which hamper its use. In a recent study, we showed that the proliferation assay can suitably replace patch testing for the diagnosis of chromium allergy, which had been previously demonstrated only for nickel allergy. In this study, we try to refine the method by reducing the incubation period of cultures for lymphocyte proliferation assays in response to chromium.

OBJECTIVE

Develop an alternative or complementary diagnostic test for chromium allergic contact dermatitis.

METHODS

We compared the production of 9 cytokines (IFN-γ, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17 and RANTES) between 18 chromium-allergic patients and 19 controls.

RESULTS

Chromium increased the production of IFN-y, IL-5, IL-2 and IL-13 in allergic patients, but only IL-2 and especially IL-13 helped discriminate allergic patients from controls. The sensitivity, specificity and accuracy found with IL-13 were about 80%.

CONCLUSIONS

IL-13 and IL-2 detection may be used to diagnose chromium allergy in 2-day cultures. However, in general, the 6-day cultures seem to be superior for this purpose.     

The Fine Scratches of the Spectacle Frames and the Allergic Contact Dermatitis

Background

Spectacle contact allergy is not infrequent. The fine scratches on the spectacle frames which may play a role in the sensitization to the potential allergenic components have not been studied.

Objective

We sought the relationship between the scratches on the spectacle frames and the allergic contact dermatitis (ACD) in the Republic of Korea.

Methods

A total of 42 Korean patients with ACD at the spectacle contact sites were enrolled. Their spectacle frames were examined with the dimethylglyoxime (DMG) test and analyzed by the scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Patch tests (thin-layer rapid use epicutaneous test [TRUE tests]) were performed to identify the skin allergens.

Results

The DMG-positive spectacle frames were identified in 78.5% of the frames. The SEM results showed that there were more scratches on the skin-contacting parts of the spectacle frames than the non-skin-contacting parts of the same frames. In the EDS findings, the mean nickel content (weight, %) of the spectacle frames was 15.7±5.5, and the mean chromium content was 20.3±3.4 at the skin-contacting parts. In the TRUE tests, nickel sulphate was the most common allergen (31 cases, 73.8%), and potassium dichromate was the second (9 cases, 21.4%). Three patients presented simultaneous positive reactions with nickel sulphate and potassium dichromate.

Conclusion

Minor visible and non-visible fine scratches on the spectacle frames may present the provocation factors of the ACD. Nickel sulphate was the most common allergen suspected of provoking the spectacle frame-induced ACD, followed by potassium dichromate.     

Diagnostic Usefulness of the Serum-Specific IgE, the Skin Prick Test and the Atopy Patch Test Compared with That of the Oral Food Challenge Test

Background

Atopic dermatitis (AD) is frequently associated with food allergies. In addition to the skin prick test (SPT) and serum-specific IgE, the atopy patch test (APT) has been introduced as a diagnostic procedure for food allergies.

Objective

Our aim was to evaluate the diagnostic value of the APT, the SPT and the serum-specific IgE levels compared with that of oral food challenge test against milk and egg in AD patients.

Methods

We conducted the SPT and APT, and determined the serum-specific IgE levels against milk and egg antigens for 101 patients. Oral food challenge tests were conducted for 86 out of 101 AD patients. The sensitivity, specificity and positive and negative predictable values were calculated for all the tests.

Results

Twenty-five patients were positive to oral food challenges. The sensitivity of the APT for milk was 66.7%, while the figures for the SPT and the serum-specific IgE were 35.5% and 14.2%. The sensitivity of the APT for egg was 50%, while that for the SPT and serum-specific IgE were 21.4% and 6.7%.

Conclusion

We were able to conclude that the APT test seems to be a valuable additional tool for the diagnostic method of food allergies in AD.     

Patch Testing with Dental Screening Series in Oral Disease

Background

The oral mucosa is constantly exposed to several irritants and allergens including dental materials, but the role of contact allergy in oral disease is obscure.

Objective

To analyze positive patch test results in patients with oral diseases and evaluate the clinical relevance of oral diseases with contact allergy to dental materials.

Methods

We retrospectively analyzed patch test results with dental screening series in 44 patients with oral disease from 2004~2011.

Results

Oral diseases included oral lichen planus (54.5%), cheilitis (27.3%), burning mouth syndrome (9.1%), and others (9.1%). Thirty-one of 44 patients (70.5%) had positive reactions to one or more allergens. The most commonly detected allergens were gold sodium thiosulfate (25.0%) and nickel sulfate (25.0%), followed by potassium dichromate (22.7%), cobalt (15.9%), palladium (6.8%), mercury (4.5%), copper (4.5%), and methylhydroquinone (4.5%). Six of 24 patients with oral lichen planus had a symptom in areas adjacent to dental materials and positive patch test reactions to allergens contained in the suspected dental materials.

Conclusion

Patch tests with dental screening series are worth considering for oral diseases, especially for oral lichen planus.     

Ultraviolet index: a light in atopic dermatitis and vitamin D research?

BACKGROUND:

The role played by vitamin D in atopic dermatitis is controversial and has been the focus of many studies. The ultraviolet index has not been considered in this type of research.

OBJECTIVES:

The objectives of the study were to assess 25-hydroxy vitamin D [25(OH)D] serum level in atopic dermatitis patients and control group, to investigate the association between atopic dermatitis clinical severity (using the SCORing Atopic Dermatitis index - SCORAD) and 25(OH)D serum levels, and to evaluate the independent predictors, including Ultraviolet index, SCORAD and 25(OH)D.

METHODS:

We conducted a cross-sectional study of 106 atopic dermatitis patients. A control group was matched with a subsample of 54 participants with atopic dermatitis. SCORAD index, laboratory tests, and local Ultraviolet index were assessed.

RESULTS:

The atopic dermatitis patients had serum 25(OH)D levels and mean UVI significantly higher than the control group. Immunoglobulin E and Ultraviolet index were associated with the SCORAD index. Skin type, age and Ultraviolet index were independent predictors of 25(OH)D.

CONCLUSIONS:

Although statistically significant, the different levels of 25(OH)D between the paired groups may be attributed to the higher mean Ultraviolet index in atopic dermatitis patients. Since Ultraviolet index is an independent predictor of SCORAD index and of 25(OH)D level, it may work as a confounding factor in studies involving atopic dermatitis and 25(OH)D and must be considered in this kind of research.     

Tissue immunostaining for factor XIIIa in dermal dendrocytes of pityriasis alba skin lesions

BACKGROUND

Pityriasis alba affects 1% of the world population and about 9.9% of the children in Brazil. However, its etiology remains uncertain.

OBJECTIVE

The objective of the present study was to evaluate the immunoexpression of factor XIIIa in dermal dendrocytes of skin lesions of pityriasis alba.

METHOD

Twenty patients with pityriasis alba and 20 patients with atopic dermatitis underwent biopsy. The dermal dendrocytes marked by factor XIIIa were counted by means of immunohistochemical analysis.

RESULTS

The mean amount of dermal dendrocytes found in the patients with pityriasis alba was 2, whereas in the patients with atopic dermatitis it was 4, with a statistically significant difference between them. A cutoff point of 3 cells/square inch was established to differentiate pityriasis alba from atopic dermatitis, with 80% sensibility and 90% specificity.

CONCLUSION

We believe that pityriasis alba and atopic dermatitis should be considered different clinical forms within the spectrum of atopic disease, in which sun radiation plays an important role by modulating the progression of the disease.     

Allergic contact dermatitis from Laurus nobilis oil induced by massage

Non-occupational contact allergy to Laurus nobilis (laurel) oil is considered rare. Herein, we report a case of allergic contact dermatitis after a massage with a mixture of olive oil and L. nobilis oil. Patch testing showed (+++) reactions to laurel oil and (++) to the mixture of olive oil and laurel oil.     

Clinical Features of Systemic Contact Dermatitis Due to the Ingestion of Lacquer in the Province of Chungcheongnam-do

Background

Lacquer contains an allergen, which can cause severe contact dermatitis. Systemic dermatitis resulting from the ingestion of lacquer is quite common in Korea, until now.

Objective

The purpose of this study is to elucidate the clinical features and laboratory findings of systemic contact dermatitis (SCD), due to the ingestion of lacquer in Chungcheongnam-do.

Methods

We retrospectively reviewed the medical records of 33 patients with SCD, after ingestion of lacquer from Soonchunhyang University Hospital in Cheonan, over a 6-month period.

Results

In this study, 33.3% of patients ate lacquer, as a health food, and some (15.2%) by encouragement of friends or spouse. The most common way of ingestion was the lacquer-boiled chicken (48.5%), but many also ate lacquer tree sprouts (42.4%). The skin lesions developed as erythematous maculopapular eruptions, erythema multiforme, erythroderma, purpura, wheals and vesicles. On laboratory findings, 13 patients (52%) exhibited leukocytosis and 11 patients had elevated eosinophil counts.

Conclusion

The general public is becoming more aware of the toxic effects of lacquer ingestion, but still does not fully understand the dangers of lacquer tree sprouts, and this ignorance is frequently causing SCD in Chungcheongnam-do.     

Relation of Nickel Allergy with in-Stent Restenosis in Patients Treated with Cobalt Chromium Stents

Background

In-stent restenosis (ISR) is the major limitation of percutaneous coronary stenting procedure. The elements like nickel, chromate and molybdenum are known to cause contact allergy. Hypersensitivity reaction, against these metal ions, may be one of the reasons of ISR. Cobalt chromium coronary stents, which are increasingly being used in percutaneous coronary interventions, have more nickel amount than the stainless steel stents.

Objective

We aimed to investigate the association between nickel hypersensitivity reaction and ISR in patients treated with cobalt chromium coronary stents.

Methods

Epicutaneous patch tests for nickel were applied to 31 patients who had undergone elective cobalt chromium coronary stent implantation and had ISR in control angiogram. Thirty patients, without ISR, were included as the control group. Patch test results and other clinical variables were compared.

Results

There was no statistically significant difference of the mean age, sex, body mass index, rate of hypercholesterolemia, diabetes, hypertension and smoking between the patients with and without ISR. All other lesion characteristics were similar in the 2 groups. According to the patch test results, 7 patients had nickel contact allergy. All of these patients were in the ISR group, which was statistically significant (p<0.006).

Conclusion

Patients treated with cobalt chromium coronary stents and had ISR were found to have significantly more nickel allergy than the control group. Nickel allergy may play role in restenosis pathophysiology.     

Polymerized Urushiol of the Commercially Available Rhus Product in Korea

Background

Systemic contact dermatitis commonly occurs with the intake of rhus (boiled chicken with rhus) as a health food and a folk medicine to cure gastrointestinal diseases in Korea. Rhus companies insist they have the technology for rhus detoxification. However, the numbers of systemic allergic contact dermatitis patients, caused by rhus, have not decreased. The principle of present techniques for rhus detoxification is the induction of the polymerization of urushiol, but polymerized urushiol may still have antigenicity, although to a diminished degree. The Korean Food and Drug Administration (KFDA) has a regulation to control urushiol use as a food. However, the laboratory method that KFDA uses for detection of rhus can only detect the urushiol monomer.

Objective

We conducted experiments to detect polymerized urushiol in rhus products, which were considered not to include urushiol by the KFDA.

Methods

Rhus product approved by the KFDA was separated with chloroform. The chloroform fractionation was accomplished on a recycle HPLC system. Four peaks were achieved and evaporated to give an amorphous powder. Each powder was analyzed on a NMR system and mass spectrometer.

Results

The material considered to be urushiol dimer, with a 638 molecular weight (MW), was detected in one of the four powders as per the HPLC peaks.

Conclusion

We concluded that commercially available rhus product is comprised of material considered to be urushiol dimer. Therefore, even if the antigenicity of the rhus products is low, this product may cause adverse effects and is not completely detoxified.     

European Surveillance System on Contact Allergies (ESSCA): polysensitization, 2009–2014

Background

Polysensitization, defined as being allergic to three or more haptens from the European baseline series, is considered to reflect increased susceptibility to developing a contact allergy, and is likely to be associated with an impaired quality of life.

Objectives

To evaluate the prevalences of polysensitization across Europe and to analyse factors associated with polysensitization.

Methods

Patch test data collected by the European Surveillance System on Contact Allergies (ESSCA; www.essca‐dc.org ) in consecutively patch tested patients from January 2009 to December 2014, comprising 11 countries and 57 departments, were retrospectively analysed.

Results

A total of 86 416 patients were available for analysis, showing a standardized prevalence of polysensitization of 7.02%, ranging from 12.7% (Austria) to 4.6% (Italy). Allergen pairs with the strongest association are reported for the total population, for South Europe, and for North/Central Europe. Overall, polysensitized patients showed a higher percentage of extreme (+++) positive patch test reactions than oligosensitized patients. Female sex, occupational dermatitis and age > 40 years were risk factors for polysensitization.

Conclusions

The varying prevalences of polysensitization across Europe most likely reflect differences in patient characteristics and referral patterns between departments. Known risk factors for polysensitization are confirmed in a European dermatitis population.

     

Analysis of MAST-CLA Results as a Diagnostic Tool in Allergic Skin Diseases

Background

Urticaria and atopic dermatitis are representative allergic skin diseases that can be mediated by IgE. Measuring levels of specific IgE can be used to confirm causative agents of these skin diseases.

Objective

To analyze results from the multiple allergosorbent test chemiluminescent assay (MAST-CLA), which measures specific IgE in the presence of a causative agent/allergen, in IgE-mediated skin diseases.

Methods

A total of 404 patients with urticaria, atopic dermatitis or pruritus were enrolled in the present study. Positive rates of specific IgE as well as total serum IgE from the MAST-CLA were compared.

Results

Positive rates of specific IgE were highest in atopic dermatitis patients, followed by urticaria, and then pruritus, with 57.0%, 37.1%, and 20.8%, respectively (p<0.05). House dust mite species were the most common allergens in both atopic dermatitis and urticaria skin diseases. There were no differences in the overall MAST-CLA results between acute and chronic urticaria. The relative positive rate of inhalant allergen was significantly higher in adult than in child atopic dermatitis patients.

Conclusion

Results from the MAST-CLA showed diversity among the three disease groups, and within each disease group, with different positive rates of specific IgE, a different mean allergen number per patient, and so on. Therefore, we concluded that MAST-CLA could be a useful diagnostic tool for various allergic skin diseases.     

Epidermal Hyperplasia and Elevated HB-EGF are More Prominent in Retinoid Dermatitis Compared with Irritant Contact Dermatitis Induced by Benzalkonium Chloride

Background

''Retinoid dermatitis'' is a retinoid-induced irritant contact dermatitis (ICD). The mechanism of retinoid dermatitis may be different from that of other ICDs. However, it remains uncertain how topical retinoid induce ICD.

Objective

We compared several aspects of contact dermatitis induced by topical retinol and benzalkonium chloride (BKC) on hairless mice skin.

Methods

2% retinol or 2.5% BKC was applied to hairless mice and transepidermal water loss (TEWL), ear thickness, histologic and immunohistochemical findings were compared. We also compared mRNA expression of inflammatory cytokines, epidermal differential markers, cyclooxygenases (COXs) and heparin binding epidermal growth factor like growth factor (HB-EGF).

Results

Topical application of 2% retinol and 2.5% BKC increased TEWL and ear thickness in similar intensity. Epidermal hyperplasia was more prominent in retinol treated skin. Proliferating cell nuclear antigen, involucrin and loricrin expression were higher in retinol-treated skin than in BKC-treated skin. Filaggrin, however, was more expressed in BKC-treated skin. The mRNA expression of IL-8, TNF-α, COX-2, involucrin, loricrin and filaggrin were increased in both retinol- and BKC-treated skin in similar intensity. HB-EGF was more significantly increased in retinol-treated skin.

Conclusion

Elevated HB-EGF and epidermal hyperplasia are more prominent features of retinoid dermatitis than in BKC-induced ICD.     

Colonization by S. Aureus increases the EASI and the number of appointments by patients with atopic dermatitis: cohort with 93 patients

BACKGROUND

Atopic dermatitis leads to epidermal barrier dysfunction and bacteria colonization. The relationship of the last factor with the severity of the disease and the frequency of exacerbation is not fully known.

OBJECTIVES

Verify the severity of the atopic dermatitis and the number of appointments generated by dermatosis, comparing patients colonized with patients not colonized by S. aureus. Verify the frequency of colonization by methicillin resistant Staphylococcus aureus acquired in the community.

METHODS

Cohort study with a 12 months follow-up, in a sample of patients from Porto Alegre, RS public network. Cultures in active injuries and nasal cavities were carried out as well as methicillin sensitivity tests to S. aureus. The severity of atopic dermatitis was defined by Eczema Area and Severity Index (EASI).

RESULTS

We included 93 patients, 43% female and 56% male, 26 colonized by S. aureus in the nasal orifices, 56 in the skin damage. The mean of initial Eczema Area and Severity Index was 5.5 and final 3.9. The initial Eczema Area and Severity Index of patients colonized by S. aureus in the skin and nasal cavity was larger than the number of patients without colonization(p< 0.05). During the period of one year, in average, there were six appointments/patient. There was linear correlation between the number of appointments during one year and the inicial Eczema Area and Severity Index (r = 0,78). There were no patients with methicillin resistant Staphylococcus aureus acquired in the community.

CONCLUSION

There is a relevant influence of staphylococcal colonization on the severity of atopic dermatitis and the number of appointments required by its exacerbation. Methicillin resistance among those affected by S. aureus does not seem to be an emergent problem, in this Brazilian sample.     

PATCH TESTING WITH DERMATOPHAGOIDES AND ITS CORRELATION WITH CHRONIC ECZEMA AND ATOPIC DERMATITIS

Background:

Chronic eczema is commonly encountered in the Indian set up. So also is atopic dermatitis. House dust mites (Dermatophagoides) are implicated in various diseases like atopic dermatitis, asthma, and perennial rhinitis. It has also been proven that patch testing with Dermatophagoides pteronyssinus (DP) is important for detection of contact sensitization in chronic dermatitis.

Aims:

To study clinical characteristics of DP mix positive patients with regards to chronic dermatitis and atopic dermatitis.

Methods:

Dermatology outpatients presenting to the department of Skin and STD of Kasturba Medical College (KMC), with clinically diagnosed atopic dermatitis and chronic eczema were chosen for the study. Inclusion and exclusion criteria were well demarked. Eighty six randomly selected patients of dermatitis were subjected to patch testing with standard series and DP mix.

Results:

Of the 86, 50 (58%) showed positive reaction to DP mix. Among these positive patients, chronic dermatitis was seen in 42 (84%) with involvement of exposed parts in 37 (74%). Atopic dermatitis was seen in 19 patients (38%) from DP positive group whereas it was observed in 4 patients (17%) from the other group.

Conclusion:

Dermatophagoides mix positivity was statistically significant in chronic eczema as well as atopic dermatitis. Patch testing is an important tool to detect delayed type allergy to house dust mite.     

Comparison of Marketed Cosmetic Products Constituents with the Antigens Included in Cosmetic-related Patch Test

Background

Currently, cosmetic series (Chemotechnique Diagnostics, Sweden) is the most widely used cosmetic-related patch test in Korea. However, no studies have been conducted on how accurately it reflects the constituents of the cosmetics in Korea.

Objective

We surveyed the constituents of various cosmetics and compare with the cosmetic series, to investigate whether it is accurate in determining allergic contact dermatitis caused by cosmetics sold in Korea.

Methods

Cosmetics were classified into 11 categories and the survey was conducted on the constituents of 55 cosmetics, with 5 cosmetics in each category. The surveyed constituents were classified by chemical function and compared with the antigens of cosmetic series.

Results

155 constituents were found in 55 cosmetics, and 74 (47.7%) of constituents were included as antigen. Among them, only 20 constituents (27.0%) were included in cosmetic series. A significant number of constituents, such as fragrance, vehicle and surfactant were not included. Only 41.7% of antigens in cosmetic series were found to be in the cosmetics sampled.

Conclusion

The constituents not included in the patch test but possess antigenicity are widely used in cosmetics. Therefore, the patch test should be modified to reflect ingredients in the marketed products that may stimulate allergies.     

Translation and validation of Portuguese of a questionnaire for evaluation of psychosomatic symptoms in adults with atopic dermatitis

BACKGROUND

atopic dermatitis is directly related to psychological stress, reduced quality of life and psychosomatic symptoms. The Psychosomatic Scale for Atopic Dermatitis is the only questionnaire developed specifically for assessment of psychosomatization in atopic dermatitis.

OBJECTIVES

the objective of this study was to cross-culturally adapt and validate a Brazilian-Portuguese version of the Psychosomatic Scale for Atopic Dermatitis.

METHODS

adaptation consisted of independent translation and backtranslation by three bilingual translators, followed by a pre-test. The Psychosomatic Scale for Atopic Dermatitis and the Dermatology Life Quality Index were self-administered to 47 patients with atopic dermatitis. Disease severity was evaluated using the Eczema Area and Severity Index. Factor analysis was used to identify the dimensions of the Brazilian Portuguese version of the Psychosomatic Scale for Atopic Dermatitis. Internal consistency and convergence validity were also analyzed. Reproducibility was assessed using the Kappa coefficient.

RESULTS

factor analysis revealed a two-dimensional structure: stress/laziness/insecurity (I) and maladjustment/social relationships (II), explaining 54.4% of total variance. All dimensions revealed excellent internal consistency. External construct validity was confirmed by positive correlations between the Psychosomatic Scale for Atopic Dermatitis and the Dermatology Life Quality Index. Test-retest reliability was excellent, with k>0.7 for all questions.

CONCLUSIONS

the Brazilian Portuguese version of the Psychosomatic Scale for Atopic Dermatitis demonstrated acceptable psychometric properties and can be used for the evaluation of psychosomatic symptoms in patients with atopic dermatitis and as a tool in clinical and epidemiological research.     

Patch tests

Patch tests were introduced as a diagnostic tool in the late nineteenth century. Since then, they have improved considerably becoming what they are today. Patch tests are used in the diagnostic investigation of contact dermatitis worldwide. Batteries or series previously studied and standardized should be used in patch testing. The methodology is simple, but it requires adequate training for the results to be correctly interpreted and used. Despite having been used for over a century, it needs improvement like all other diagnostic techniques in the medical field.     

Aeroallergen Patch Testing in Patients of Suspected Contact Dermatitis

Background:

Aeroallergens are airborne substances present in the environment with the potential to trigger an allergic reaction in the respiratory tract, mucosae, or skin of susceptible individuals. The relevance of aeroallergens in the pathogenesis of atopic dermatitis has been reported by many investigators. However, very few studies have been conducted to investigate their role in the production of allergic contact dermatitis (ACD).

Aims:

To determine the prevalence of aeroallergen patch test positivity in patients of suspected ACD and to study the clinical characteristics of patients testing positive with aeroallergens.

Materials and Methods:

Patients presenting to our department with suspected contact allergy and undergoing patch testing with Indian Standard Series (ISS) between January 2010 and June 2011 were studied. After a detailed history and clinical examination, patients were patch tested with ISS and aeroallergen series. Based on the history and clinical suspicion, patients were additionally patch tested with 15% Parthenium. Prior tape stripping was done in some patients.

Results:

Out of total 114 patients, 26 (22.8%) showed sensitivity to aeroallergen series. Parthenium was the commonest aeroallergen being positive in all 26 patients followed by Xanthium in two. None reacted to other allergens. Although positivity was more in patients with prior tape stripping, the difference was not statistically significant.

Conclusion:

Most common aeroallergen found to be positive in our study was Parthenium hysterophorus. In view of low positivity to other allergens, routine aeroallergen patch testing in patients with suspected contact dermatitis may not be necessary.