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

Occupational skin diseases is one of the top occupational diseases, and the most common form is contact dermatitis accounting for 90%. In healthcare workers, allergens most commonly identified are preservatives, excipients in cleansers, antiseptics and rubber accelerators. Contact dermatitis has a major impact in performance at the workplace and overall quality of life. Allergen avoidance is the cornerstone of management of contact dermatitis, and this poses a challenge to those exposed in the workplace.

A 31-year-old female nurse, with no known comorbidities, presented with several-years history of on-off episodes of pruritic, scaly plaques on the hands that would occasionally have fissures with associated 8/10 pain. She sought consult with several physicians, diagnosed as non-specific eczema, and was prescribed topical steroids and antihistamines with partial improvement. Due to the recurrence of the lesions, an 83-allergen patch test was done. There was a +2 reaction to carba mix noted as erythematous, indurated papules and plaque with pinpoint crusts. A definite relevance was identified since the patient works as a nurse with regular use of rubber gloves. The patient was diagnosed with allergic contact dermatitis, and advised measures to avoid exposure to the allergen.

Carba mix contains diphenylguanidine, zinc dibutyldithiocarbamate and zinc diethyldithiocarbamate, and can be found in rubber products such as gloves. Healthcare workers, especially nurses, are constantly exposed to this allergen since gloves are part of the standard and basic personal protective equipment. This case outlines the impact of patients’ occupation to their overall health.

Dyshidrotic eczema (DE) and palmoplantar psoriasis (ppPSO) are both conditions presenting with vesicopustules on the palms and soles. While they have differences, distinguishing them can be a challenge in cases complicated with allergic contact dermatitis (ACD).

A 24-year-old male clerk, presented with a one-year history of vesicopustules on the palms and soles, associated with onycholysis and subungual hyperkeratosis. He admits to frequent hand washing and using rubbing alcohol as well as wearing a new pair of rubber shoes. Patch testing (International Standard series) showed +++ Potassium dichromate 0.5%, Carba Mix 3.0%, Thuiram mix 1.0%, Textile dye 6.6% and ++ Formaldehyde 2%. Gram stain was negative and KOH from plantar area showed spores and long-septate hyphae. Dermoscopy showed a bright pink background with erosions, patchy dotted vessels atop with yellow crust, and scales. Histopathology revealed psoriasiform-spongiotic dermatitis with macrovesiculation and eosinophilic spongiosis which was consistent with subacute eczema. He was managed as a case of recalcitrant DE with secondary dermatophytosis and ACD to textile dye and rubber, but still keeping in mind the possibility of eczematized ppPSO. The patient was managed accordingly, with particular emphasis on avoiding allergens. The condition improved, and nail changes resolved with topical medications and a short course of oral corticosteroid and oral anti-fungal thus favoring our initial impression of recalcitrant DE complicated by dermatophytosis and ACD.

This highlights the diagnostic challenge in distinguishing between severe DE and ppPSO in the setting of concomitant ACD, underscoring the importance of a comprehensive evaluation.

Acrodermatitis continua of Hallopeau (ACH) is a chronic, rare pustular form of psoriasis that affects the distal extremities, particularly the fingers and toes. Although pustules are characteristic, they may not always be clinically apparent, especially in the earlier stages. This condition is often resistant to treatment; therefore, early and accurate diagnosis is essential for proper management and preventing complications.

A 34-year-old male farmer presented with a one-year history of pruritic erythematous scaly plaques involving both palms, thumbs and thumbnails. Pertinent history showed that the lesions appeared after contact with rubber gloves and fertilizers. Irritant versus allergic contact dermatitis were considered, but a negative patch test result ruled out the allergic component. He was treated with topical corticosteroids and was advised to wear cotton gloves under rubber gloves while working which provided relief. However, the plaques recurred now with appearance of pustules on both hands. A skin punch biopsy was done revealing psoriasiform dermatitis with subcorneal pustules, consistent with ACH. The patient was started on methotrexate 7.5 mg/week and topical clobetasol, alternating with calcipotriol with improvement of the palmar plaques and pustules.

ACH is often misdiagnosed due to its pus-filled lesions which may mimic infection or secondarily infected contact dermatitis or dyshidrotic eczema. In this case, the initial presentation mimicked a contact dermatitis, and it was only after patch testing and skin biopsy, that a definitive diagnosis was made.

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*

OBJECTIVES: Ozone is widely applied to treat allergic skin diseases such as eczema, atopic dermatitis, and contact dermatitis. However, the specific mechanism remains unclear. This study aims to investigate the effects of ozonated oil on treating 2,4-dinitrochlorobenzene (DNCB)-induced allergic contact dermatitis (ACD) and the underling mechanisms. METHODS: Besides the blank control (Ctrl) group, all other mice were treated with DNCB to establish an ACD-like mouse model and were randomized into following groups: a model group, a basal oil group, an ozonated oil group, a FcεRI-overexpressed plasmid (FcεRI-OE) group, and a FcεRI empty plasmid (FcεRI-NC) group. The basal oil group and the ozonated oil group were treated with basal oil and ozonated oil, respectively. The FcεRI-OE group and the FcεRI-NC group were intradermally injected 25 µg FcεRI overexpression plasmid and 25 µg FcεRI empty plasmid when treating with ozonated oil, respectively. We recorded skin lesions daily and used reflectance confocal microscope (RCM) to evaluate thickness and inflammatory changes of skin lesions. Hematoxylin-eosin (HE) staining, real-time PCR, RNA-sequencing (RNA-seq), and immunohistochemistry were performed to detct and analyze the skin lesions. RESULTS: Ozonated oil significantly alleviated DNCB-induced ACD-like dermatitis and reduced the expressions of IFN-γ, IL-17A, IL-1β, TNF-α, and other related inflammatory factors (all P<0.05). RNA-seq analysis revealed that ozonated oil significantly inhibited the activation of the DNCB-induced FcεRI/Syk signaling pathway, confirmed by real-time PCR and immunohistochemistry (all P<0.05). Compared with the ozonated oil group and the FcεRI-NC group, the mRNA expression levels of IFN-γ, IL-17A, IL-1β, IL-6, TNF-α, and other inflammatory genes in the FcεRI-OE group were significantly increased (all P<0.05), and the mRNA and protein expression levels of FcεRI and Syk were significantly elevated in the FcεRI-OE group as well (all P<0.05). CONCLUSIONS Ozonated oil significantly improves ACD-like dermatitis and alleviated DNCB-induced ACD-like dermatitis via inhibiting the FcεRI/Syk signaling pathway.
Animals ; Mice ; Dinitrochlorobenzene/metabolism* ; Skin/metabolism* ; Cytokines/metabolism* ; Interleukin-17/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Dermatitis, Allergic Contact/pathology* ; Dermatitis, Atopic/chemically induced* ; Signal Transduction ; RNA, Messenger/metabolism* ; Mice, Inbred BALB C

OBJECTIVE: To investigate the anti-inflammatory potential of Ampelopsis japonica on contact dermatitis (CD). METHODS: A total of 38 Balb/c mice were divided into 5 groups by using a random number table: normal mice (n=6), CD model mice (n=8), CD mice treated with 3 or 30 mg/kg of the ethanol extract of A. japonica (EEAJ, n=8) and 7.5 mg/kg dexamethasone treated CD mice (DEX, n=8). CD was induced using topical application of 1-fluoro-2,4-dinitrofluorobenzene in mice. EEAJ and DEX were topically applied to the shaved skin of each mouse for 6 days, and the effects of EEAJ and DEX on skin lesions and color, histopathological abnormalities such as epidermal hyperplasia and immune cell infiltration, and tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) production were investigated. The effects on changes in body weights and spleen/body weight ratio were also investigated. RESULTS: EEAJ at 30 mg/kg significantly prevented scaling, erythema and enlargement of skin weight compared to using carbon dioxide. EEAJ also prevented epithelial hyperplasia and immune cell infiltrations induced by repeated application of DNFB (P<0.01). In addition, EEAJ significantly lowered levels of TNF-α, IL-6 and MCP-1 (P<0.05 or P<0.01). The anti-inflammatory effects of EEAJ were similar to those of DEX. CONCLUSION A. japonica may be a new therapeutic agent with the potential to reduce or replace corticosteroids and its mechanisms are closely related to regulation of TNF-α production.
Ampelopsis ; Animals ; Anti-Inflammatory Agents/therapeutic use* ; Cytokines ; Dermatitis, Contact/pathology* ; Dinitrofluorobenzene/therapeutic use* ; Hyperplasia/drug therapy* ; Interleukin-6 ; Mice ; Mice, Inbred BALB C ; Plant Extracts/therapeutic use* ; Tumor Necrosis Factor-alpha

Background: Oral lichen planus is an idiopathic autoimmune inflammatory condition and oral lichenoid reactions are lesions that resemble oral lichen planus clinically and histopathologically, but develop secondary to various underlying causes. Oral lichenoid reactions have been reported to be caused by contact allergy to dental materials. This study aims to describe the characteristics of patients with a clinical and/or histopathological diagnosis of oral lichen planus who underwent patch testing in Hospital Kuala Lumpur, Malaysia. Methods: This is a 5-year retrospective study of patients who had oral lichen planus and had undergone patch testing at the Department of Dermatology, Hospital Kuala Lumpur, Malaysia between January 2015 and Cecember 2019. Patch tests were performed with European Baseline Series and relevant extended series, which include dental and metal series as well as patients’ own products. Patch test results were recorded according to the International Contact Dermatitis Research Group recommendation. Results: There were 41 patients with oral lichen planus who underwent patch test. The median age was 56 (range 21 to 73) with 70.7% of patients being female. There were 29 (70.7%) patients who developed at least one positive reaction. The most frequent sensitizing allergens were nickel sulfate (34.1%), gold(I)sodium thiosulphate dihydrate (22.0%), fragrance mix I (19.5%), cobalt chloride (14.6%), Peru balsam (12.2%) and sodium tetrachloropalladate (II) hydrate (12.2%). Current relevance was recorded in 16 patients (39.0%) and of these patients, 12 of them had positive patch test reactions to allergens found in dental materials such as dental fillings, dental implants, orthodontic braces, dentures and dental crowns. Conclusion Contact sensitization was detected in about 70% of our patients with oral lichen planus. The most common sensitizing allergen was nickel sulfate. Current relevance was found mainly towards dental materials.
Lichen Planus, Oral--diagnosis ; Dermatitis, Allergic Contact ; Department of Dermatology, Hospital Kuala Lumpur (Malaysia)

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