Epicutaneous Tests Research Articles

Sensitivity and specificity of the modified epicutaneous patch test in the diagnosis of respiratory allergy to Dermatophagoides pteronyssinus

The skin prick test is recognized as the gold standard for the specific diagnosis of allergy. To determine the sensitivity and specificity of the epicutaneous patch test that has been modified for the diagnosis of respiratory allergy to Dermatophagoides pteronyssinus. An observational, interpretative, prolective, and transversal study. The included patients were between 6 and 49 years old, with symptoms of a respiratory allergy, and a skin test was performed on them by using the European standardized prick test and a modified epicutaneous patch test with the variable of the scarification that occurred before the antigen was applied, and its homogenization with a wooden applicator, which occurred after the antigen was applied. The levels of sensitivity, specificity, and prevalence influence and positive and negative predictive values were calculated. 104 patients were included, of which 72 (69.2%) were women. The age category of the patients was 24 ± 11.3 years of age. 78.9% of the patients were diagnosed with allergic rhinitis, 1.9% were diagnosed with asthma, and 19.2% were diagnosed with both rhinitis and asthma. The prevalence of the respiratory allergy to Dermatophagoides pteronyssinus was of 62.5%; 94.23% with a correct diagnosis. The sensitivity and specificity of the test was of 93.85% and 94.87%; the positive and negative predictive values were of 96.83% and 90.24%, and the positive and negative likelihood ratios were of 18.30 and 0.06. The modified epicutaneous patch test was highly sensitive and specific; it decreased the risk of allergen carryover and it lowered the cost of the material that was used.

Effect of topical pramoxine hydrochloride on discomfort, wheal and flare associated with epicutaneous allergy test

Effect of topical pramoxine hydrochloride on discomfort, wheal and flare associated with epicutaneous allergy test

Experience in patch testing: A 6-year retrospective review from a single academic allergy practice

BackgroundPatch testing is the “gold standard” to identify culprit allergen(s) causing allergic contact dermatitis (ACD), but there are limited studies of patch testing from allergy practice settings. ObjectiveWe sought to explore patch test findings in a large academic allergy practice, including patch testing results, history of atopy, location of dermatitis, and referral source. We also wanted to determine whether patch testing using an extended panel, such as the North American screening series, compared with a limited series, such as the Thin-Layer Rapid-Use Epicutaneous (T.R.U.E.) Test, increased the sensitivity. MethodsA retrospective chart review was conducted of patients referred for patch testing over a 6-year period. ResultsA total of 585 patients (mean age 48.7 years, 71.6 % female) underwent patch testing over the 6-year period, of which 369 (63%) had a positive test. Of those who tested positive, 202 (55%) reported a history of atopy. The extremities were the most commonly involved site, followed by the head/neck and trunk. The 5 most common positive allergens were nickel sulfate, gold sodium thiosulfate, methylchloroisothiazolinone, thimerosal, and bacitracin. Three hundred fourteen (53.6%) patients were positive to at least 1 allergen on TRUE testing. Extended screening series identified an additional 10.8% of patients with positive tests who were negative to T.R.U.E. test allergens. ConclusionPatch testing is a valuable diagnostic tool for the practicing allergist and provides early identification of culprit allergens in ACD. Performing an extended screening series such as the North American Contact Dermatitis Group (NACDG) or supplemental panel of allergens increased sensitivity when compared with a limited series.

A case series of cementless revision total knee arthroplasty in patients with benzoyl peroxide allergy.

The contact allergens nickel, cobalt, and chromium are often discussed as possible triggers of allergic reactions to orthopedic implants. Additionally, acrylates and polymerization additives in bone cement (e.g., benzoyl peroxide (BPO)) have been implicated as triggers of eczema, wound healing disorders, and aseptic implant loosening. We report about six patients with aseptic loosening after total knee arthroplasty (TKA), who underwent revision surgery after testing positive for BPO hypersensitivity. After clarification of possible other causes of implant failure, epicutaneous testing had been performed and the implants were replaced in a two-stage procedure with cementless, diaphyseal anchoring, hypoallergenic (TiNb-coated) revision endoprostheses. Epicutaneous testing revealed a BPO allergy in all six patients and an additional nickel allergy in three of the six patients. There was no histopathological or microbiological evidence for a periprosthetic infection. The clinical follow-up showed a low level of pain with good function, a stable knee joint, and proper implant position. The Knee Society Score (KSS) with its subscales Knee Score and Functional Score improved post-operatively from 43 to 70 points and from 47.5 to 68.3 points, respectively. Two implant-specific complications occurred: femoral stress shielding two years post-operatively with no further need for action and aseptic loosening of the tibial stem with the need of revision threeyears post-operatively. The regression of complaints after replacement with cementless and nickel-free revision implants suggests allergic implant intolerance. Implantation of a cementless, hypoallergenic endoprosthesis might, therefore, be a surgical treatment strategy in patients with evidence of allergies.

Pterostilbene Attenuates Hexavalent Chromium-Induced Allergic Contact Dermatitis by Preventing Cell Apoptosis and Inhibiting IL-1β-Related NLRP3 Inflammasome Activation

Hexavalent chromium (Cr(VI)) is widely used in many industries but can induce contact dermatitis especially in cement industries. Many cement workers suffer from Cr(VI)-induced allergic contact dermatitis (ACD), and prevention and therapeutic strategies are still lacking. Pterostilbene (PT) is a natural compound predominantly found in blueberries. Studies indicate the potential use of PT as an effective anti-oxidative and anti-inflammatory agent. Herein, we investigated the possible mechanisms involved and whether chromium-induced ACD could be effectively inhibited by treating PT. In our in vivo study, epidermal Cr(VI) administration causes cutaneous inflammation in mice ear skin, and the pro-inflammatory cytokines, TNF-α and IL-1β, were found in the epidermis, presenting the level of increase after Cr(VI) treatment. Meanwhile, the results of our in vitro experiment showed that apoptosis and endoplasmic reticulum (ER) stress were induced after treatment with different concentrations of Cr(VI) in HaCaT cells (human keratinocyte). Cr(VI) also induced TNF-α and IL-1β mRNA expressions, through the activation of the p38 mitogen-activated protein kinase (MAPK)/MAPK-activated protein kinase 2 (MK2) pathway. Notably, the severity of the skin reactions in the epicutaneous elicitation test significantly diminished when the mouse was treated with PT. Likewise, PT intervention also ameliorated the inflammation and apoptosis of HaCaT cells in vitro. Furthermore, our current findings demonstrated that the NLRP3 inflammasome could be involved in the Cr(VI)-mediated inflammation and apoptosis of ACD. Thus, interrupting this mechanism with proper nontoxic agents, such as PT, could be a new option to improve occupational chromium toxicity and hypersensitivity.

RAPID INTRAVENOUS DESENSITIZATION TO HORSE ANTITHYMOCYTE GLOBULIN IN A WOMAN WITH SEVERE APLASTIC ANEMIA

Introduction Antithymocyte globulin (ATG) and cyclosporine is a first line regimen for the treatment of severe aplastic anemia in patients without a matched sibling donor for transplant. Administration of ATG is associated with life threatening anaphylaxis in up to 5% of post-marketing cases. Accordingly, the manufacturer's insert recommends skin testing prior to first-time administration of ATG. We present a case of a 59 year-old woman with positive skin testing to horse ATG, who underwent successful desensitization to ATG for treatment of her severe aplastic anemia. Case Description A 59 year-old woman with severe aplastic anemia was admitted to our institution for induction therapy with ATG and cyclosporine. Pre-treatment skin testing to ATG was positive, with a 13 mm wheal after intradermal injection of 5 mcg of ATG. Epicutaneous skin testing was negative. She underwent successful rapid intravenous desensitization to ATG with no adverse reactions during the procedure. She completed a four-day cycle of ATG and was started on daily cyclosporine. She had good response to ATG treatment, and at six-month follow-up, she had continued clinical remission sustained with cyclosporine and eltrombopag. Discussion Our patient's positive intradermal skin testing was suggestive of a Type I hypersensitivity to ATG. Patients with positive skin testing should avoid ATG or undergo desensitization when medically necessary. Previous reports have described several cases of life threatening hypoxia and hypotension during ATG desensitization, but our patient successfully underwent a rapid intravenous desensitization and subsequently tolerated a four-day continuous infusion of ATG.

Acacia seyal and Terminalia brownii associated airborne contact dermatitis (Dukhan dermatitis).

Taking scented smoke baths (Dukhan) is a universal custom among African women who indulge in it for pleasure, cleanliness, health, and for restoration after childbirth. The woods used in this procedure are usually Acacia seyal and Terminalia brownii. This report is a case series of 11 women with brown-erythematous excoriated papules, plaques, and lichenification confined to the sites of scented smoke baths. They were diagnosed with airborne contact dermatitis on the basis of patient history, existence of dust agents, the morphology and distribution of the lesions, the results of epicutaneous tests (repeated open application test), and avoidance of further exposure leading to recovery from dermatitis.

Drug Hypersensitivity.

Adverse drug reactions (ADRs) can be divided into pharmacological ADRs (type A) and hypersensitivity reactions (type B). Type B reactions can be further subdivided into immediate (<1 h, urticaria, anaphylaxis) and delayed reactions (>1 h, variable manifestation like exanthema, hepatitis, cytopenias). Prevention of hypersensitivity is often still a challenge. Selective literature search in Medline and Google Scholar as well as research in ADR databases like OpenVigil or SIDER. Laboratory tests ([specific] IgE, lymphocyte transformation test), histological examination, dermatological tests (prick tests, epicutaneous testing) and-under certain circumstances-provocation tests can be used for diagnostics. There are only a few pharmacogenetic biomarkers to predict hypersensitivity reactions. Currently, testing for defined HLA genes is mandatory before prescription of abacavir and before the use of carbamazepine in Han Chinese or Thai patients. Immediate discontinuation of the trigger is essential in all allergic hypersensitivity reactions. Immediate reactions are treated with antihistamines, glucocorticoids and occasionally with epinephrine. Delayed reactions are usually treated with glucocorticoids. Careful, structured diagnostics in case of suspected hypersensitivity together with adequate documentation (allergy passport) is necessary in order to avoid incidents in patients receiving subsequent treatment. Consistent use of existing resources (diagnostics and documentation) can help to avoid hypersensitivity reactions or to rapidly recognize and treat them, respectively.

Pediatric Baseline Patch Test Series: Pediatric Contact Dermatitis Workgroup.

Allergic contact dermatitis is a challenging diagnostic problem in children. Although epicutaneous patch testing is the diagnostic standard for confirmation of contact sensitization, it is less used in children by dermatologists treating children, pediatric dermatologists, and pediatricians, when compared with adult practitioners. The aim of the study was to create and evaluate standardization of a pediatric patch test series for children older than 6 years. We surveyed dermatologists and allergists conducting epicutaneous patch testing in children attending the 2017 American Contact Dermatitis Society meeting held in Washington, DC. This was followed by discussion of collected data and consensus review by a pediatric contact dermatitis working group at the conference. A baseline pediatric patch test panel was established through working group consensus.

Prevalence of food allergens sensitization and food allergies in a group of allergic Honduran children

BackgroundFood allergy is a public health problem that has increased in the last decade. Despite the increasing rates in children, quality data on the burden of these diseases is lacking particularly in developing countries. Honduras has no studies in pediatric patients.ObjectivesThe objective of this research was to identify the most common sensitization patterns to food through epicutaneous skin testing and food allergy rates in children and their correlation with common allergic diseases in a group of patients from Hospital of Pediatrics Maria.MethodsCross-sectional retrospective, descriptive study in which records and database of all allergic patients in the immunology outpatient clinic from Hospital of Pediatrics Maria were reviewed between the periods of January 2015 through June 2016.ResultsA total of 365 children were analyzed, the age of participants were in the range from 1 to 18 years, with an average of 9.8 years. Sensitization to food allergens were found in 23, and 58.3% were poly-sensitized. The most common food allergens that patients were sensitized to: milk 9.0%, eggs 6.9%, peanut 4.9% and pork meat 4.4%. Food allergy was confirmed via oral food challenged in 9.3% of the patients. The most frequent food allergies found were: cow’s milk allergy 6%, hen’s egg allergy 5.2% and wheat allergy 1.9%.ConclusionsMilk and egg were the most common a food allergens found in the population studied. Most of the patients were found to be poly-sensitized. The frequent food allergies confirmed via oral food challenge were cow’s milk allergy, hen’s egg allergy and wheat allergy.

Hand eczema in children. Clinical and epidemiological study of the population referred to a tertiary hospital

Abstract Introduction Hand eczema is a frequent disease in adults. Diagnosing the cause of hand eczema is difficult due to different classifications. There is lack of evidence on hand eczema and its causes in children. Material and method A total of 389 children between 0 and 16 years were identified between 1996 and 2016, from whom 42 (10.8%) with exclusively hand eczema were selected. In all cases a standard battery of epicutaneous patch tests was performed, as well as additional batteries depending on the clinical suspicion. The clinical and epidemiological features of these children were recorded and compared against children with eczema in other locations. Results The 42 children with hand eczema included 25 (59.5%) girls, and 17 (40.5%) boys, with a mean age of 10.6 ± 3.9 years, and did not differ from that of children with eczema in other locations. The definitive diagnosis after patch-testing was Atopic Dermatitis in 15 cases, Allergic Contact Dermatitis in 14 patients, Endogenous Vesiculous Eczema in 6 cases, Endogenous Hyperkeratotic Eczema in 5 cases, and Irritant Contact Dermatitis in 2 cases. The most frequent allergens detected were thiomersal (9 cases), nickel (5 cases), mercury (5 cases), and cobalt (4 cases). Conclusion Hand eczema is a common condition in children. The most common cause is atopic dermatitis, although cases of allergic contact dermatitis manifesting as hand eczema are not uncommon. Any child with eczema of hands in whom an allergic cause is suspected should be referred for patch- testing.

Dermatite de Contacto aos Tiurans – a propósito de um caso clínico

Os tiurans são substâncias utilizadas como aditivos - adicionados ao látex, no fabrico de artigos de borracha. A hipersensibilidade aos tiurans é uma reação tipo IV, tardia e mediada por linfócitos T e manifesta-se por dermatite de contacto alérgica (DCA). Os autores apresentam o caso clínico de uma menina de 9 anos de idade com episódios de edema palpebral, labial e peri-oral, associado a lesões do tipo eczema, com placas eritematodescamativas, todos com exposição prévia a materiais de borracha. A investigação foi positiva no teste epicutâneo para mistura de tiurans. Com a evicção destes produtos a menina não voltou a ter manifestações clínicas. Muitos doentes referenciados por dermatite de contacto aos produtos de borracha têm hipersensibilidade retardada aos aditivos da borracha como os tiurans e carbamatos e não ao látex, e esta reação pode ser confirmada por testes epicutâneos.

Para-phenylenediamine and its multiple co-sensitisations – two case reports

Introduction. In contact allergology, the situations with simultaneous positive tests to multiple molecules are not rare; sometimes, in these cases, interpretation and clinical relevance of the tests are difficult. Case report I. A 73-year-old woman, with chronic blepharoconjunctivitis and chronic rhinitis (under observation), not responding to the treatment with tobramycin ophthalmic drops, olopatadine ophthalmic drops, dexamethasone phosphate injectable solution, mometazone furoate nasal spray and fluorometholone ophthalmic drops. Personal history: ten years ago - dermatitis on the face and scalp after using black dye hair. Epicutaneous tests: European Baseline Series + additional series, three components of cortico­steroid series. Results: +++ to para-phenylenediamine (PFD), ++ to neomycin, Peru balsam, budesonide, tixocortol-21-pivalate, benzalkonium chloride, textile dye mix, disperse orange. Case report II. A 50-year-old woman, without personal history of atopy, presented three months ago an acute eczema on the scalp and neck after using black dye hair. Under treatment with strong corticosteroids, the evolution was favorable, the eczema being at the time of testing in the chronic stage (lichenification). Epicutaneous tests: European Baseline Series + additional series. Results: ++ to PFD and nickel, + to colophane, Peru Balsam, Paladium, Orange Disperse 1, textile dye mix. Clinical relevance of the tests. In both cases primary sensitization was caused by hair dye, the responsible hapten being para-phenylenediamine; the positive results to textile dye mix and disperse orange 3 in the first case, respectively, to textile dye mix and disperse orange 1, in the second case, are justified by the cross-reactions they may have with PFD. The positivity of the tests to budesonide and tixocortol pivalate but also to benzalkonium chloride, in the first case, can be explained by sensitization via fluorometolone, respectively, by the presence of benzalkonium chloride as an excipient in dexamethasone phosphate injectable solution,tobramycin ophthalmic drops, olopatadine ophthalmic drops and fluorometholone ophthalmic drops. Conclusion. Our results are concordant with those recently published, which showed that PFD is one of the top-ranking allergens regarding the absolute number of significant associations with concomitantly patch tested allergens, suggesting the possibility to identify a subset of patients who are genetically prone to multiple sensitizations.

Analysis of Epicutaneous Patch Test Results in Patients with Contact Dermatitis.

Background:Allergic contact dermatitis (ACD) is a delayed type of hypersensitivity from contact with a specific allergen to which the patients has developed a specific sensitivity. The aim of the study was to evaluate the results of epicutaneous patch testing with standard series of contact allergen in patients suspected to have ACD.Methods:355 cases of ACD were included in the study. Test substances were applied on the upper part of the patient’s back, on clinically uninvolved and untreated skin. All patients were free from therapy with oral antihistamines, steroids and immunosuppressants. The patch test was removed and reaction were evaluated after 48 h and 72 h. Grading of negative (-) to positive (+ to ++++) patch test was done according to the International Contact Dermatitis Research Group. Statistical data analysis was performed by using χ2–test.Results:Of the 355 cases, 146 patients were male (41.1%) and 209 were female (58.9%). The youngest patients in the study was 16 years of age and the oldest was 67 years of age. The commonest age group affected was 41-50 years. Hands were the most common site of involvement. The occupational character of skin lesions was find in 75 (21.1%). The most common positive reactions were recorded to nickel sulphate 99 (27.8%), cobalt chloride 46 (12.9%), thimerosal 31 (8.7%), colophony 23 (6.5%), carba mix 21 (5.9%), potassium dichromate 20 (5.6%), acid chromici 19 (5.3%), fragrance mix 18 (5%), balsam of Peru 13 (3.7%), formaldehyde 9 (2.5%), and other allergens 26 (7.3%). Females were significantly more likely to show a positive response to two or more allergens (p<0.05). There was no statistically significant impact of age, occupation and duration of disease on results of patch testing (p>0.05).Conclusions:Our results indicate that nickel sulphate, cobalt chloride and thimerosal are the most common allergens responsible for induction of ACD. These findings are crucial in the treatment, long term management, an education of patients with ACD.

Antituberculosis Drug-Associated DRESS: A Case Series

Although antituberculosis drug-associated drug reaction with eosinophilia and systemic symptoms (DRESS) is rarely reported, its diagnosis should not be dismissed. Its management implies an early withdrawal of suspected drugs. The objective of this study was to describe the characteristics of antituberculosis drug-associated DRESS and to identify the most likely involved drugs. We searched for potential cases of DRESS with rifampicin, isoniazid, pyrazinamide, and ethambutol reported from January 1, 2005, to July 30, 2015, in the French pharmacovigilance database. A literature review was also performed. Sixty-seven cases of antituberculosis drug-associated DRESS were analyzed (40 women and 27 men, median age of 61years). Liver and kidneys were the most frequently involved organs. Two patients died from DRESS. Skin tests were performed in 11 patients and were positive in 8 cases. Discrepancies between epicutaneous tests and reintroduction of the culprit drugs were observed for 2 patients with a premature reintroduction of antituberculosis drugs in 1 case. Antituberculosis drugs were the only suspects in 20 cases. As for the literature data, rifampicin was the most suspected drug because of its larger indications, but in case of tuberculosis infections, isoniazid was the most suspected drug. We described the largest case series of first-line antituberculosis drug-associated DRESS in the literature. All antituberculosis drugs pose a risk of DRESS. An early withdrawal of the culprit drugs is essential. A drug allergy evaluation must be performed to optimize the second-line treatment of tuberculosis infection.

Thin-Layer Rapid Use Epicutaneous Patch Test (T.R.U.E. Test) for Confirmation of Contact Sensitization

ABSTRACT The patch test is considered the gold standard for the diagnosis of allergic contact dermatitis. The Thin-Layer Rapid Use Epicutaneous Patch Test (T.R.U.E. Test) is a patch test approved by the U.S. Food and Drug Administration containing 35 preloaded, ready-to-apply allergens and allergen mixes. Our objective is to provide a comprehensive review of the commercially available patch test kit.

Chronic hand eczema: is IL-36α helpful in diagnosis and classification?

Chronic hand eczema (CHE) is not a homogenous disease, necessitating complex differential diagnostics. Interleukin (IL) -1 family members are significantly up-regulated in ACD and psoriasis patients skin. The present study aims to deepen the knowledge about clinical assessment and characterization of patients affected by chronic hand dermatitis (CHD) as well as to investigate the role of possible biomarkers which may help in the diagnostic process. An observational case-control study was performed enrolling 30 CHD patients and 20 healthy controls. Each patient underwent detailed medical history, clinical examination, epicutaneous patch test, and lesional skin biopsies for histological and immunohistochemical analysis. Patient history, clinical examination and patch testing led us to a final CHD characterization in only 8/30 subjects (26.7%). In the remaining subjects, clinical and histological features suggested a diagnosis of psoriasis in 9/22 (30%) and idiopathic chronic hand eczema (CHE) in 13/22 (43.3%). Trying to find a possible marker for the latter dermatosis, we analyzed IL-1 family in all the recruited subjects. IL-1 members were increased in all conditions, but IL-36α was the only analyzed cytokine able to characterize patients who end up with a diagnosis of idiopathic CHE. In conclusion, we can assess that medical history and patch testing remain essential investigations in CHD patients even if not always sufficient to perform a final diagnosis. Moreover, IL-1 members are probably involved in CHE skin inflammation, with IL-36α being a possible future biomarker which might help in the complex diagnostic process of CHE.

Screening for skin-sensitizing allergens among patients with clinically suspected allergic contact dermatitis.

Objectives:To detect common skin-sensitizing agents among patients experiencing allergic contact dermatitis (ACD).Methods:This was a retrospective study of 152 patients with clinically suspected ACD who underwent patch testing in an allergy clinic at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between January 2012 and February 2015. Of these patients, only 74 (48%) patients reacted to one or more contact allergens. This group of patients included 58 (78.4%) women and 16 (21.6%) men (mean age: 37.8±13.8 years). Patch testing was performed using the thin-layer rapid-use epicutaneous patch test panels.Results:Nickel sulfate was the most common sensitizing agent, with 26 (35.1%) patients yielding a positive result; followed by p-phenylenediamine in 17 (22.9%), butyl-tetra-phenol formaldehyde in 12 (16.2%), gold sodium thiosulfate in 10 (13.5%), and thimerosal in 6 (8.1%) patients. Nickel reactivity was significantly higher among women (41.4%) than among men (12.5%) (p<0.0001). Similarly, gold reactivity among women (15.5%) was also higher than among men (6.2%) (p≤0.02).Conclusion:The high level of skin sensitization due to nickel, PPD, and gold in patients with ACD emphasizes the need for measures to decrease exposure to these sensitizing agents.

Dental patch testing in patients with undifferentiated oral lichen planus.

Distinguishing between oral lichen planus (LP) and lichenoid reactions to dental restorations can be impossible on clinical and histopathological grounds. Epicutaneous patch testing is an investigation that may guide patients and physicians in making timely and costly decisions to replace or cover existing dental restorations. This study aimed to assess the role of epicutaneous patch testing with a battery of dental allergens in patients with undifferentiated oral LP. A retrospective review of the medical records of patients with biopsy-proven oral LP referred by an oral medicine specialist and who presented for dental epicutaneous patch testing at a dermatology clinic in Perth, Western Australia between 2009 and 2016 was performed. In total, 68 patients were included, of whom 54 (79%) had positive patch tests. Gold 26 (48%), mercury 24 (44%), nickel 22 (41%), copper 19 (35%), potassium dichromate 14 (26%) and methylhydroquinone 13 (24%) were the most common allergens for which patients tested positive. Hypothyroidism and non-steroidal anti-inflammatory drugs were associated with negative patch tests (P=0.01 and 0.04, respectively). Smoking history, other medications and comorbidities, the location of the dental restorations and unilateral or bilateral disease were not significantly associated with the patch test results. Restorations were removed in 23 patients: 21 of these (91%) had positive epicutaneous patch tests. Of the 20 patients followed up, 19 (95%) experienced some improvement, among whom 11 (58%) had complete remission. Epicutaneous patch testing disclosed a high proportion of relevant positives. This guided the clinical decision to change dental restorations, with high rate of clinical improvement.

Allergic contact dermatitis of the scalp

Contact allergy represents an important differential diagnosis to other skin diseases of the scalp. The typical efflorescences, spreading in the periphery, pruritus, and the clinical history support the differential diagnosis. Since the scalp is particularly resistant to contact dermatitis, allergens applied to this area often produce dermatitis of the eyelids, ears and neck. Nevertheless, potent allergens such as para-phenylendiamine can also cause severe reactions of the scalp. The most important allergens eliciting contact allergy of the scalp are found in bleaches and dyes, shampoos and conditioners, products for perm waves and straighteners as well as topical drugs. Besides active ingredients or drugs, vehicles and preservative agents represent additional allergens. The use of topical steroids and oral antihistamines usually results in rapid resolution of the dermatitis, systemic steroids are only necessary in severe cases. Epicutaneous patch testing on the basis of available series combined with the ingredients of the suspected elicitors confirms the diagnosis and facilitates allergen avoidance as well as the selection of alternative products.