Contact dermatitis.

Contact dermatitis (CD) is among the most common inflammatory dermatological conditions and includes allergic CD, photoallergic CD, irritant CD, photoirritant CD (also called phototoxic CD) and protein CD. Occupational CD can be of any type and is the most prevalent occupational skin disease. Each CD type is characterized by different immunological mechanisms and/or requisite exposures. Clinical manifestations of CD vary widely and multiple subtypes may occur simultaneously. The diagnosis relies on clinical presentation, thorough exposure assessment and evaluation with techniques such as patch testing and skin-prick testing. Management is based on patient education, avoidance strategies of specific substances, and topical treatments; in severe or recalcitrant cases, which can negatively affect the quality of life of patients, systemic medications may be needed.

Comparison of Nickel Sulfate 2.5% and Nickel Sulfate 5% for Detecting Nickel Contact Allergy.

BACKGROUND: Nickel is among the most common contact allergens found on patch testing worldwide and, because of its ubiquitous nature in our environment, often has important implications for allergen avoidance strategies. In both North America and Europe, nickel positivity is found in approximately 20% of patients who undergo patch testing. Whereas in North America, nickel sulfate is typically tested at a concentration of 2.5%, in Europe, it is tested at a 5% concentration. OBJECTIVE: The primary objective was to assess the differences in patch test positivity to nickel sulfate 2.5% and 5%. METHODS: We investigated 205 consecutive patients between September 2017 and February 2018 who were tested to nickel sulfate at concentrations of both 2.5% and 5%. RESULTS: Among the 205 patients tested, 33% were positive (+, ++, or +++) to at least 1 concentration of nickel sulfate, 20% were positive to nickel sulfate 2.5%, and 31% were positive to nickel sulfate 5% (χ1(N = 205) = 16.1, P = 0.0001). Patients were 6.5 times more likely to have a positive reaction to nickel sulfate 5% than 2.5% (odds ratio 95% confidence interval, 2.3-25.6). CONCLUSIONS: Given our findings, we propose an additional evaluation of nickel sulfate 5% as a standard allergen for patch testing in North America.

A case series of dupilumab-treated allergic contact dermatitis patients.

Atopic dermatitis is characterized by skin barrier abnormalities and immune dysregulation with increased TH 2 signaling playing a central role. Investigations of allergic contact dermatitis suggest that certain allergens may also activate particular T cell signatures such as TH 2-dominant responses to fragrance and rubber. We present a case series of patients with allergic contact dermatitis who were successfully treated with dupilumab, a biologic developed for atopic dermatitis that dampens TH 2 signaling. In our cohort of three patients, two had extensive allergic contact dermatitis on their torso and extremities primarily due to textile and rubber allergens. The third was a hairdresser with severe hand dermatitis due to occupational allergens. Two of the three patients had no history of atopic dermatitis during childhood. Each patient experienced at least 90% improvement in body surface area involvement and continues to maintain their clinical response on dupilumab (range 6-13 months). Our hypothesis that dupilumab suppressed contact allergic reactions is supported by the identification of clinically relevant contact allergens on patch testing, acute onset and/or worsening of dermatitis in adulthood, and absence of childhood atopic dermatitis in two cases. Further, larger investigations to understand which factors affect responses of allergic contact dermatitis to dupilumab are warranted.

Benzalkonium Chloride: An Irritant and Sensitizer.

BACKGROUND: Benzalkonium chloride (BAK) is a known irritant, and potentially cross-reacting quaternary ammonium compounds are commonly used as preservatives in personal care products. OBJECTIVE: The aim of the study was to review positive reactions to BAK in 615 patients patch tested for suspected allergic contact dermatitis. METHODS: A retrospective chart review was performed in 615 patients patch tested from June 2015 to October 2016. All patients were tested to a Modified American Contact Dermatitis Society core series of 70 allergens including BAK (0.1% aqueous). Initial readings were performed at 48 hours with final readings performed between 72 and 168 hours. Results were graded as + (weak: papules and erythema), ++ (strong: papules and edema or vesicles), or +++ (extreme: coalescing vesicles, spreading or bullous reactions). RESULTS: A total of 141 men (23%) and 475 women (77%) were tested (mean age, 49 years). Four hundred thirty-two (70%) were atopic. Of 615 patients, 198 (32%) tested positive to BAK, and 64 (10%) had ++ or +++ reactions at their final reading. On average, BAK-positive patients were using at least 1 product containing BAK or possible cross-reactors. CONCLUSIONS: Widespread exposure to irritants in dermatitis patients can predispose to sensitization. Products containing BAK or potential cross-reactors should be used carefully in patients with compromised skin barriers.

Patch Testing for Evaluation of Hypersensitivity to Implanted Metal Devices: A Perspective From the American Contact Dermatitis Society.

The American Contact Dermatitis Society recognizes the interest in the evaluation and management of metal hypersensitivity reactions. Given the paucity of robust evidence with which to guide our practices, we provide reasonable evidence and expert opinion-based guidelines for clinicians with regard to metal hypersensitivity reaction testing and patient management. Routine preoperative evaluation in individuals with no history of adverse cutaneous reactions to metals or history of previous implant-related adverse events is not necessary. Patients with a clear self-reported history of metal reactions should be evaluated by patch testing before device implant. Patch testing is only 1 element in the assessment of causation in those with postimplantation morbidity. Metal exposure from the implanted device can cause sensitization, but a positive metal test does not prove symptom causality. The decision to replace an implanted device must include an assessment of all clinical factors and a thorough risk-benefit analysis by the treating physician(s) and patient.

Patch test results in psoriasis patients on biologics.

OBJECTIVES: The objective of this study was to determine the prevalence of positive patch tests in patients with psoriasis receiving biologics and whether these results differ from those of patients with psoriasis not on biologics. METHODS: An institutional review board-approved retrospective chart review was conducted for patients with psoriasis patch tested January 2002-2012 at Tufts Medical Center. Patients had a history of psoriasis, psoriatic arthritis, and patch testing as identified by International Classification of Diseases, Ninth Revision codes 696.1, 696.0, and 95044, respectively, in their records. Patients were tested to a modified North American Contact Dermatitis Group standard and cosmetics series. Readings were performed at 48 hours and 72 to 96 hours. The North American Contact Dermatitis Group grading system was used to grade reactions. RESULTS: Fifteen patients with psoriasis on biologics (cases) and 16 patients with psoriasis not on biologics (control subjects) were studied. The biologics used were ustekinumab (n = 7), etanercept (n = 4), adalimumab (n = 3), and infliximab (n = 1). Eighty percent (12/15) of cases had at least 1 positive reaction compared with 81% (13/16) of the control subjects; 67% (10/15) of cases had 2+ reactions compared with 63% (10/16) of the control subjects, and 27% (4/15) of cases had 3+ reactions, compared with 38% (6/16) of control subjects. These differences were not statistically significant. CONCLUSIONS: Given the limitation of small numbers of patients, biologics do not appear to influence the abilities of patients with psoriasis to mount a positive patch test.

Contact allergy to sorbitans: a follow-up study.

BACKGROUND: Sorbitan sesquioleate (SSO), an emulsifier in many corticosteroids, was previously found positive in 8.9% of 112 dermatitis patients. OBJECTIVE: The objective of this study was to present data on 24 of 591 dermatitis patients with reactions to SSO and/or sorbitan monooleate (SMO) on patch testing. METHODS: A retrospective chart review was conducted on 591 consecutive dermatitis patients patch tested from November 2008 to May 2010. In addition to being tested to a modified North American Contact Dermatitis Group standard series, all patients were tested to a cosmetic series. RESULTS: Of the 591 patients tested, 24 reacted to SSO and/or SMO (4.1%), 19 (3.2%) reacted to SSO alone, 1 (0.17%) to SMO alone, and 4 (0.68%) reacted to both. Of the 24 sorbitan-allergic patients, 2 (8.3%) reacted to any of 4 corticosteroid screening chemicals tested. CONCLUSIONS: In this follow-up study, 4.1% of 591 dermatitis patients reacted to SSO and/or SMO. Given the presence of SSO in many popular topical corticosteroid formulations, clinicians should consider allergy to sorbitans when patients do not improve with topical corticosteroid therapy.

The role of contact allergens in chronic idiopathic urticaria.

OBJECTIVE: The objective of this study was to determine whether contact allergens play a role in chronic idiopathic urticaria (CIU). METHODS: We conducted a longitudinal prospective study of 23 patients with CIU. Patients were patch tested to a modified North American Contact Dermatitis Group standard, fragrance, and cosmetic series; other series were tested as warranted by relevant history and physical examination. Readings were performed at 48 and 72 hours. Patients were counseled to avoid proven contact allergens and were followed up 2 to 9 months after testing. RESULTS: Twenty-one of 23 patients were female. The mean age was 46 years. The mean duration of urticaria was 32 months. Of the 23 patients, 8 (35%) experienced improvement of their symptoms with allergen avoidance. Four (17%) experienced a complete remission, and 4 (17%) experienced partial improvement. Two of the complete responders challenged themselves to proven contact allergens and developed urticaria, which resolved upon allergen avoidance. The most common allergens were potassium dichromate (n = 9), nickel sulfate (n = 7), Myroxylon pereirae (n = 6), cobalt chloride, neomycin, p-phenylenediamine (n = 5); fragrance mix I, fragrance mix II (n = 4); cinnamic aldehyde (n = 3); and formaldehyde (n = 2). CONCLUSIONS: Patch testing may be helpful in the evaluation of CIU patients for whom previous workup has failed to reveal an etiology.