Peter C. Schalock

Hypersensitivity reactions to metallic implants – diagnostic algorithm and suggested patch test series for clinical use

Cutaneous and systemic hypersensitivity reactions to implanted metals are challenging to evaluate and treat. Although they are uncommon, they do exist, and require appropriate and complete evaluation. This review summarizes the evidence regarding evaluation tools, especially patch and lymphocyte transformation tests, for hypersensitivity reactions to implanted metal devices. Patch test evaluation is the gold standard for metal hypersensitivity, although the results may be subjective. Regarding pre‐implant testing, those patients with a reported history of metal dermatitis should be evaluated by patch testing. Those without a history of dermatitis should not be tested unless considerable concern exists. Regarding post‐implant testing, a subset of patients with metal hypersensitivity may develop cutaneous or systemic reactions to implanted metals following implant. For symptomatic patients, a diagnostic algorithm to guide the selection of screening allergen series for patch testing is provided. At a minimum, an extended baseline screening series and metal screening is necessary. Static and dynamic orthopaedic implants, intravascular stent devices, implanted defibrillators and dental and gynaecological devices are considered. Basic management suggestions are provided. Our goal is to provide a comprehensive reference for use by those evaluating suspected cutaneous and systemic metal hypersensitivity reactions.

Pragmatic approach to the clinical work-up of patients with putative allergic disease to metallic orthopaedic implants before and after surgery

Allergic complications following insertion of metallic orthopaedic implants include allergic dermatitis reactions but also extracutaneous complications. As metal‐allergic patients and/or surgeons may ask dermatologists and allergologists for advice prior to planned orthopaedic implant surgery, and as surgeons may refer patients with complications following total joint arthroplasty for diagnostic work‐up, there is a continuous need for updated guidelines. This review presents published evidence for patch testing prior to surgery and proposes tentative diagnostic criteria which clinicians can rely on in the work‐up of patients with putative allergic complications following surgery. Few studies have investigated whether subjects with metal contact allergy have increased risk of developing complications following orthopaedic implant insertion. Metal allergy might in a minority increase the risk of complications caused by a delayed‐type hypersensitivity reaction. At present, we do not know how to identify the subgroups of metal contact allergic patients with a potentially increased risk of complications following insertion of a metal implant. We recommend that clinicians should refrain from routine patch testing prior to surgery unless the patient has already had implant surgery with complications suspected to be allergic or has a history of clinical metal intolerance of sufficient magnitude to be of concern to the patient or a health provider. The clinical work‐up of a patient suspected of having an allergic reaction to a metal implant should include patch testing and possibly in vitro testing. We propose diagnostic criteria for allergic dermatitis reactions as well as noneczematous complications caused by metal implants.

Acupuncture compared with oral antihistamine for type I hypersensitivity itch and skin response in adults with atopic dermatitis – a patient‐ and examiner‐blinded, randomized, placebo‐controlled, crossover trial

Itch is the major symptom of atopic dermatitis (AD). Acupuncture has been shown to exhibit a significant effect on experimental itch in AD. Our study evaluated acupuncture and antihistamine itch therapy (cetirizine) on type I hypersensitivity itch and skin reaction in AD using a patient and examiner‐blinded, randomized, placebo‐controlled, crossover trial.

The Brain Circuitry Mediating Antipruritic Effects of Acupuncture

Itch is an aversive sensory experience and while systemic therapies, such as acupuncture, have shown promise in alleviating itch in patients suffering from chronic itch, their antipruritic mechanisms are unknown. As several lines of evidence implicate brain-focused mechanisms, we applied functional magnetic resonance imaging and our validated temperature-modulation itch model to evaluate the underlying brain circuitry supporting allergen-induced itch reduction in atopic dermatitis patients by acupuncture, antihistamine, and respective placebo treatments. Brain response to allergen itch demonstrated phase dependency. During an increasing itch phase, activation was localized in anterior insula and striatum, regions associated with salience/interoception and motivation processing. Once itch reached peak plateau, robust activation was noted in prefrontal cognitive and premotor areas. Acupuncture reduced itch and itch-evoked activation in the insula, putamen, and premotor and prefrontal cortical areas. Neither itch sensation nor itch-evoked brain response was altered following antihistamine or placebo acupuncture. Greater itch reduction following acupuncture was associated with greater reduction in putamen response, a region implicated in motivation and habitual behavior underlying the urge to scratch, specifically implicating this region in acupunctures antipruritic effects. Understanding brain circuitry underlying itch reduction following acupuncture and related neuromodulatory therapies will significantly impact the development and applicability of novel therapies to reduce an itch.

Metal hypersensitivity reactions to implants: opinions and practices of patch testing dermatologists.

BackgroundCutaneous metal hypersensitivity reactions (MHR) are common but rare with implanted devices. ObjectivesThis study aimed to characterize the opinions of dermatologists who are actively evaluating/advising patients with MHR. MethodsA questionnaire was distributed to all individuals who attended the European Society of Contact Dermatitis (ESCD) 2012 and the American Contact Dermatitis Society 2013 meetings. ResultsA total of 119 individuals responded with a participation rates of 10% (ESCD) and 32% (American Contact Dermatitis Society). Ninety-six percent of the respondents evaluate MHR and 91% were attending physicians. Orthopedic and dental devices were common problems compared with cardiovascular devices. Patch testing is the top choice for evaluating MHR. Lymphocyte transformation and intradermal tests are rarely used. Eighty-two percent of the respondents evaluate plastic/glue components in symptomatic patients postimplant. Most dermatologists use a tray specifically for joint allergy or a history-based custom array of allergens. Those patients with a strong clinical history of metal allergy should be evaluated before metal implantation (54%), whereas others forgo evaluation and recommend a titanium implant based on history alone (38%). Diagnostic criteria for postimplant reactions were evaluated. Eight percent of the respondents felt that no evaluation was necessary, with ESCD respondents being significantly more likely to not recommend evaluation (P = 0.001). ConclusionsMetal hypersensitivity reactions consultation requests are common for preimplant and postimplant issues. Patch testing is currently the best test for MHR.

Contact sensitization pattern in 172 atopic subjects

Background  Some authors have claimed a decreased cell‐mediated immunity among atopic individuals, which would lead to observations of decreased rates of allergic contact dermatitis (ACD).

The imagined itch: brain circuitry supporting nocebo-induced itch in atopic dermatitis patients.

Psychological factors are known to significantly modulate itch in patients suffering from chronic itch. Itch is also highly susceptible to both placebo and nocebo (negative placebo) effects. Brain activity likely supports nocebo‐induced itch, but is currently unknown.

OA08.04. Brain circuitry subserving acupuncture relief of itch in atopic dermatitis: an fMRI study

Purpose Chronic itch is a prevalent symptom of many inflammatory skin disorders, including atopic dermatitis (AD). While conventional systemic approaches to reduce AD itch have shown limited efficacy and/or significant side effects, several recent studies have demonstrated effectiveness of acupuncture for reducing itch in healthy adults and AD. We sought to evaluate the brain circuitry underlying acupuncture reduction of itch.

Periorbital Contact Sensitization

PURPOSE To identify frequency and pattern of contact sensitization among patients with periorbital dermatitis. DESIGN Cross-sectional retrospective investigation of 1247 patients referred for patch testing over a 17-year period. METHODS Data were collected for patients undergoing patch testing to the standard and customized trays between January 1990 and December 2006 at the Massachusetts General Hospital, Contact Dermatitis Clinic. Our study group consisted of 266 patients affected by periorbital dermatitis. Findings were compared to 981 referrals without periorbital dermatitis (controls). Patch test results were read after 48 and 72 hours and classified as allergic, questionable, irritant, or negative. Statistical analyses were carried out by using chi(2) test and Fisher exact test. RESULTS General epidemiologic data among periorbital dermatitis patients showed significant predominance of female gender (87.6%) and of individuals aged 40 to 59 years (45.9%). Nickel (16.5%) and fragrance mix (13.2%) were the top-ranking sensitizers. Ingredients of topical ophthalmologic products did not result in significant sensitization. Comparison of the periorbital dermatitis group to the controls did not reveal significant differences in sensitization pattern. Patch testing confirmed the likelihood of allergic contact dermatitis in 50.8% of the periorbital dermatitis patients tested. CONCLUSIONS Allergic contact dermatitis is a common cause of periorbital dermatitis. Patch testing should be considered in all patients with periorbital dermatitis when suspecting contact allergy in order to identify and avoid offending allergens.

Patch testers' opinions regarding diagnostic criteria for metal hypersensitivity reactions to metallic implants.

BackgroundMetal hypersensitivity reactions to implanted devices remain a challenging and controversial topic. Diagnostic criteria and methods are not well delineated. ObjectiveDiagnostic criteria for hypersensitivity reactions after metallic device implantation are evaluated in this study by a multinational group of patch testers using Thyssen’s previously published criteria. MethodsA total of 119 dermatologists at the 2012 European Contact Dermatitis Society and 2013 American Contact Dermatitis Society meetings answered a survey regarding their opinions on topics relating to metal hypersensitivity. ConclusionsFour major and 5 minor diagnostic criteria emerged. Approximately 80% of respondents found the following criteria useful (major criteria): chronic dermatitis beginning weeks to months after metallic implantation, eruption overlying the metal implant, positive patch test to a metal component of the implant, and complete clearing after removal of the potentially allergenic implant. Minor criteria (<61% of respondents) were as follows: systemic allergic dermatitis reaction, therapy-resistant dermatitis, morphology consistent with dermatitis, histology consistent with allergic contact dermatitis, and a positive in vitro test to metals (eg, lymphocyte transformation test). In the challenging situation such as a symptomatic or failing orthopedic device, applying these 4 major criteria and the 5 supportive minor criteria may be useful for guiding decision making.