Background: Allergic contact dermatitis (ACD) is a common skin inflammatory reaction occurring at the site of challenge with a contact allergen in sensitized individuals and one of the most common causes for consultation in dermatology clinics. Patch testing is a method for detecting the causative component in suspected cases of ACD. Awareness about the causative allergen aids in reducing morbidity and can significantly minimize the impact of ACD in the affected people. Objectives: The study aimed to measure the number of relevant positive reactions in patch tests being performed in our institution in patients with ACD to cosmetic products. Methods: A total of 60 patients who were diagnosed with ACD to cosmetics and underwent patch testing were reviewed to identify the clinico‑epidemiological and patch test profiles of these patients. Results: The study showed that the mean age of patients was 42 comprising mostly of females. Most of the patients were unemployed, office workers, and medical workers. The most common cosmetic products that caused ACD include soaps, shampoos, lotions, and moisturizers. Nickel is still the most tested positive among these patients, followed by fragrance mixes and 4‑phenylenediamine base. They are widely distributed in cosmetic products, especially in soaps and lotions. The pattern of dermatitis revealed facial dermatitis to be the most common reason for consult of these patients. Conclusion Patch test is valuable in the setting of establishing the etiology of ACD to cosmetic products.
Dermatitis, Allergic Contact ; Cosmetics ; Patch Tests

INTRODUCTION

Allergic contact dermatitis remains a commonly encountered condition in dermatology. Contact allergen prevalence fluctuates over time, making ongoing surveillance essential for detecting trends and identifying emerging allergens.

To determine the prevalence and trends of top allergen patch test-positive patients over a 10-year period.

The medical records of 906 patients who underwent patch testing at the hospital between 2012 and 2021 were retrospectively reviewed. Clinical data and patch tests results with clinical relevance from consultation records were extracted and analyzed.

In the 10 years, data from 996 patients patch tested with European baseline series of contact allergens were analyzed. The overall positivity rate was 64.25%. The predominant allergens investigated during the previous decade include nickel sulfate (19.60%), fragrance mix I (8.70%), potassium dichromate (5.99%), cobalt chloride (5.92%), and p-phenylenediamine base (5.92%). The trend in our study aligns with global patch test data, with nickel sulfate consistently leading as the most frequent allergen.

The study emphasizes the need for regular monitoring and updating of the standard patch test series to ensure its clinical relevance and improve patient care.

In China, the current standard for cosmetic adverse reactions related skin disease (GB/T 17149.1-1997) was jointly issued by the Ministry of Health and the State Bureau of Technical Supervision in 1997, cosmetic-allergic adverse reactions include allergic contact dermatitis and photo-allergic contact dermatitis according to this standard. The increasing use and changes in cosmetic ingredients or formula lead to a significant increase for the incidence of adverse reactions as the cosmetics industry is developing rapidly in the last 20 years. In the meantime, the clinical manifestations have become more diverse. In recent years, there have been many reports on the special manifestations for cosmetic allergy and allergen test, which provide a reference for the subsequent improvement of the diagnosis and prevention.
Humans ; Patch Tests/adverse effects* ; Dermatitis, Allergic Contact/therapy* ; Cosmetics/adverse effects* ; China ; Incidence ; Allergens/adverse effects*

INTRODUCTION: Pigmented contact dermatitis (PCD) is characterized by non-eczematous pigmentation associated with contact sensitizers, usually without any active or preceding pruritus and erythema. PCD was first described by Riehl, who identified patients with brown to gray facial pigmentation concentrated on the face most commonly associated with sensitizing chemical such as cosmetics, fragrances, and textiles. CASE REPORT: This is a case of a 48-year-old female Filipino who presents with blue-grey to brown patches on the forehead of 1-year duration with no significant pathologic history. Clinical examination, dermoscopy and histology were consistent with a variant of pigmented contact dermatitis known as Riehl melanosis. Since anamnesis was unremarkable, patch testing was done to identify the contact allergen triggering the symptom. Results obtained a positive reaction to nickel, potassium dichromate, and textile dye. CONCLUSION:Treatment includes the elimination of trigger factors, hence the importance of patch testing in the investigation of its cause. Alongside adequate photoprotection, a combination treatment of 1,064 nm Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, 20% tricholoacetic acid (TCA) peel and oral retinoids, were found safe and effective in the management of facial melanosis. Three-dimensional imaging and dermoscopy were utilized to obtain a more standard and objective pre- and post-treatment comparison.
Lasers, Solid-State ; Patch Tests ; Melanosis ; Skin Abnormalities ; Dermatitis, Contact

BACKGROUND: Rosacea is a relatively common inflammatory skin disease characterized by central facial erythema that persists for several months or longer. Experimental studies have demonstrated that rosacea compromises the epidermal barrier protection against allergens and irritants, rendering rosacea patients susceptible to contact hypersensitivity and skin irritation. OBJECTIVE: This study aimed to investigate allergic and irritant reactions to topical agents and cosmetics in rosacea patients using patch tests. METHODS: Rosacea signs and subtypes of 40 patients were recorded and subjective symptoms and clinical experiences related to topical agents and cosmetics were assessed using a questionnaire. Patch tests were performed in these patients using the Korean Standard Series (Chemotechnique Diagnostics, Sweden), the TRUE test® (Mekos Laboratories ApS, Denmark), and 26 selected fragrance and 31 cosmetic antigens (TROLAB, Germany). RESULTS: Of 40 patch-tested patients, 26 (65%) showed at least 1 positive reaction and 13 (32.5%) showed 2 or more positive reactions. The most common allergens were nickel (II) sulfate (50%), cobalt chloride (10%), epoxy resin (7.7%), and thimerosal (7.5%). Thirteen patients (32.5%) experienced irritant patch test reactions. There were no significant differences in allergic or irritant positive reactions between mild, moderate, and severe cases of rosacea or between rosacea subtypes. Irritant reactions were more common in fair-skinned participants. CONCLUSION: Different topical medications are used in the treatment of rosacea patients. Exacerbation of rosacea may be caused by a hypersensitivity reaction or irritation induced by the topical agent or by cosmetics.
Allergens ; Clinical Study ; Cobalt ; Dermatitis, Contact ; Erythema ; Humans ; Hypersensitivity ; Irritants ; Nickel ; Patch Tests ; Rosacea ; Skin ; Skin Diseases ; Thimerosal

BACKGROUND: Mutation in the gene encoding filaggrin (FLG) is a major predisposing factor for atopic dermatitis (AD), in association with distinct features such as increased allergic sensitization, higher severity, and frequent skin infections. Genetic diversity in FLG mutations exists across ethnicities. OBJECTIVE: This study aimed to investigate the clinical features of AD according to the presence of FLG mutation in Korean individuals. METHODS: We performed reverse blot hybridization assay to detect FLG mutation in Korean patients with AD. Classifying subjects into AD with or without FLG mutation, clinical features of AD and patch test results were compared between the two groups. RESULTS: Among a total of 281 subjects, 39 (13.9%) were found to have FLG mutation. AD with FLG mutation was associated with higher risk of impetigo and eczema herpeticum but lower risk of prurigo nodularis. In the patch test, there was no difference in positive reactions of major contact allergens between the groups. CONCLUSION: In Korean patients with AD, FLG mutation was associated with more frequent skin infections but not with personal or family history of atopic diseases, allergic sensitization, contact allergy, and protracted course. It is important to consider other skin-barrier-related genes, such as KLK7 and SPINK5, and immune response-related genes in conjunction.
Allergens ; Causality ; Dermatitis, Atopic ; Genetic Variation ; Humans ; Hypersensitivity ; Impetigo ; Kaposi Varicelliform Eruption ; Patch Tests ; Prurigo ; Skin

Anaphylaxis is a sudden-onset life-threatening systemic hypersensitivity reaction. Allergens, such as foods, stinging insect venoms, and drugs, are the globally important causative factors for anaphylaxis. Para-phenylenediamine (PPD), an aromatic amine, is a well-known hair dye component that can act as a skin irritant and/or a skin sensitizer. As an allergen, PPD can induce various reactions; the most common being contact dermatitis, a delayed-type hypersensitivity reaction. Anaphylaxis or other immediate hypersensitivity reactions by hair dye contact is extremely rare, with only a few cases reported worldwide. Here, we report a case of a 63-year-old female who presented to the Emergency Department with dyspnea, rash, vomiting, and diarrhea within minutes after using a hair dye product containing PPD. Her past medical history includes urticaria of unknown cause. Her total IgE antibody level was increased to 630 kU/L. Skin prick and patch tests with the hair dye she applied at the time of anaphylaxis demonstrated an immediate reaction. An additional patch test with 25 common contact allergens showed positive reaction to PPD. This is the first case report of hair dye-induced contact anaphylaxis presenting sensitization to PPD in Korea.
Allergens ; Anaphylaxis ; Bites and Stings ; Dermatitis, Contact ; Diarrhea ; Dyspnea ; Emergency Service, Hospital ; Exanthema ; Female ; Hair Dyes ; Hair ; Humans ; Hypersensitivity ; Hypersensitivity, Immediate ; Immunoglobulin E ; Insects ; Korea ; Middle Aged ; Patch Tests ; Skin ; Urticaria ; Venoms ; Vomiting

The major apple allergen Mal d 1 cross-reacts with the homologous birch pollen allergen Bet v 1 and causes immunoglobulin E (IgE)-mediated immediate-type allergic reactions. In some patients, delayed-type hypersensitivity to apples may develop within 72 hours without evidence of specific IgE or a positive skin prick test (SPT). The aim of the study was to evaluate the concomitance of delayed-type hypersensitivity reactions and immediate IgE-mediated reactions against high- and low-allergenic apple cultivars in patients with birch pollen allergy. Data were obtained from 45 adults with clinical symptoms of birch pollen allergy. Patients were exposed to apple pulp via atopy patch tests (APTs) and SPTs. Levels of IgE specific to Bet v 1 and Mal d 1 were measured with a radioallergosorbent test. Patients allergic to birch pollen showed the highest rate of positive SPT responses to Golden Delicious apples and the lowest rate to low-allergenic cultivar Grey French Reinette. Among these patients, 9% developed delayed hypersensitivity reactions to either Golden Delicious or Grey French Reinette apples; these reactions manifested clinically as erythema with papules (class ++). Fifty percent of APT-positive patients were concomitantly SPT-negative. Here, we show for the first time the clinical relevance of T cell-driven allergic reactions to apples. APTs may reveal type IV sensitization in patients who are negative for the corresponding type I sensitization tests. Thus, utilization of the APT procedure with fresh apple appears to be a valuable tool for the diagnosis of apple allergy and may improve the accuracy of food allergy diagnoses.
Adult ; Betula* ; Diagnosis ; Erythema ; Food Hypersensitivity ; Humans ; Hypersensitivity* ; Hypersensitivity, Delayed ; Immunoglobulin E ; Immunoglobulins ; Incidence* ; Malus* ; Patch Tests ; Pollen* ; Radioallergosorbent Test ; Rhinitis, Allergic, Seasonal ; Skin

Acute generalized exanthematous pustulosis (AGEP) is rarely caused by radiocontrast media (RCM). The role of skin tests for the diagnosis and evaluation of cross-reactivity in a delayed type of RCM-induced hypersensitivity have yet to be determined. Here, we report a case of iodixanol-induced AGEP where we safely administered alternative RCM using patch tests. A 44-year-old woman had coronary artery angiography (CAG) for the evaluation of ischemic heart disease. She was on regular hemodialysis because of end-stage renal disease. She was given iodixanol (Visipaque) during CAG. Approximately 1 day after CAG, she developed AGEP. The patient was rehospitalized for CAG again after 1 year. We performed skin tests to choose safe alternative RCM. Intradermal tests with iodixanol, iohexol (Bonorex) and Iopamidol (Pamiray) showed negative responses. Patch tests showed a positive response to iodixanol, equivocal to iohexol, and negative to Iopamidol. We finally chose Iopamidol and performed CAG successfully without any adverse reaction. Patch tests may be a useful tool for the diagnosis and choice of safe alternatives in RCM-induced delayed-type hypersensitivity reactions such as AGEP.
Acute Generalized Exanthematous Pustulosis* ; Adult ; Angiography ; Contrast Media* ; Coronary Vessels ; Diagnosis ; Female ; Humans ; Hypersensitivity ; Intradermal Tests ; Iohexol ; Iopamidol ; Kidney Failure, Chronic ; Myocardial Ischemia ; Patch Tests* ; Renal Dialysis ; Skin Tests

BACKGROUND: Henna is a natural dye derived from the leaves of the tree Lawsonia inermis known for its very low allergic properties. Recently, however, cases of pigmented contact dermatitis after henna dyeing have been increasing. OBJECTIVE: To analyze the clinical and histologic features of pigmented contact dermatitis caused by henna dyeing. METHODS: We retrospectively reviewed the clinical and histopathologic features of patients diagnosed with pigmented contact dermatitis after henna dyeing from June 2014 to August 2017. RESULTS: A total of 22 patients with a history of henna dyeing were included. All patients were female, and mean age was 58.9±8.2 years. They presented with rapidly spreading dark brownish patches located mostly adjacent to the hairline, such as at the forehead, temple, and lateral cheek. The mean duration between symptom onset and henna dyeing was 4.52 months (0~15). Standard patch test and as is test using henna showed no significant results. There were 18 patients with pruritus, which was only present at the early stage. Histopathologic examinations showed lichenoid inflammation with dermal melanin incontinence, vacuolar alteration, epidermal apoptotic cells, and perivascular inflammation. CONCLUSION: These results suggest that pigmented contact dermatitis observed after henna dyeing was caused by the toxicity of henna itself, not by other additives. The active ingredient of henna is lawsone (2-hydroxy-1,4-naphthoquinone), which may have induced pigmented contact dermatitis by its own cellular toxicity. Dermatologists should consider henna dyeing as a potential cause of pigmentation of the face and neck.
Cheek ; Dermatitis, Contact* ; Female ; Forehead ; Humans ; Inflammation ; Lawsonia Plant ; Melanins ; Neck ; Patch Tests ; Pigmentation ; Pruritus ; Retrospective Studies ; Trees