Intradermal testing in the diagnosis of allergic contact dermatitis. A reappraisal

Overcoming False-Negative Patch Tests: A Systematic Literature Review

Exogenous allergens, found in cosmetic products, jewelry items, antiseptics and antibacterials, plants, and solvents, can cause clinical allergic contact Dermatitis (ACD). To help identify and discern which allergen is causing ACD, clinicians use patch tests, but they can yield false-negative results at times. Examining potential reasoning for false negatives is particularly helpful when a patient's history and physical examination strongly suggest ACD, and the patch test is negative. A strong history and physical presentation suggestive of ACD warrants additional patch testing or other methods to verify a false-negative patch test result. We conducted a literature review to compile various reasonings and solutions for false-negative patch tests in suspected ACD patients. Utilizing EMBASE, Scopus, PubMed, and Google Scholars, 49 articles were included by using search terms such as "False negative patch test" or "False-negative patch test" and "allergic contact Dermatitis," or "ACD." Common factors that led to false-negative patch test results include low allergen concentration, inadequate percutaneous penetration, technique error, immunosuppressive therapy, and ultraviolet exposure. Potential solutions include using different vehicles, concentration, increasing reading time, repeating the patch test, intradermal testing, and repeat open application testing. If a false-negative patch test is suspected, then intradermal testing can be administered to ensure the specificity of the patch test result. Considering the main contributing factors and solutions to false-negative patch tests, clinicians can accurately diagnose ACD and administer proper treatment plans.

Metal Hypersensitivity or Missed Periprosthetic Joint Infection? A Critical Review

The World Association Against Infection in Orthopedics And Trauma (W.A.I.O.T.) Study Group on Bone And Joint Infection Definitions Metal hypersensitivity (MHS) has been investigated by several authors as a possible reason for painful total joint arthroplasty, with controversial results. Periprosthetic joint infection (PJI) is another possible source of unexplained pain and implant failure that may be difficult to diagnose if not properly investigated. We performed this critical review to assess whether the current literature on MHS includes an adequate diagnostic workup to discern metal allergy from PJI. The results of this review highlight the importance of assessing patients for PJI before making a diagnosis of MHS and emphasize that the methods currently used to exclude PJI are substantially inadequate. Therefore, well-designed clinical trials with adequate diagnostic protocols and definitions of PJI that can differentiate MHS from low-grade PJI are needed. [Orthopedics. 2022;45(2):e73-e78.].

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.

Metal Hypersensitivity Reactions to Orthopedic Implants

Total hip and knee replacement surgery using metal alloy devices is common. Type IV allergic reactions to these implants occur, though infrequently. While uncommon, peri-implant metal allergic reactions may cause significant morbidity for the affected individual-including aseptic loosening, pseudotumor formation and frank device failure. It is challenging to predict who will have these reactions, even in those with established pre-implant metal allergy. At this time, the scientific literature clearly supports few conclusions. Despite this, we believe several conclusions can be made: routine pre-implant testing in asymptomatic individuals is not indicated; listen to patient's concerns about metal allergy if the concern arises; patch testing is probably the best pre- and post-implant screening test; post-implantation testing is controversial and even positive LTT or patch test does not definitively diagnose morbidity from a metal allergy; and complete recovery following revision placement of an immunologically inert device is diagnostic. More research is needed to scientifically approach this issue.

Serum Biomarkers of Allergic Contact Dermatitis: A Pilot Study

BACKGROUND

Allergic contact dermatitis (ACD) is an inflammatory skin disease caused by repeated skin exposure to contact allergens. The goal of this pilot study was to identify inflammatory proteins which can serve as biomarkers for ACD.

METHODS

We measured levels of 102 cytokines, chemokines, and growth factors in the sera of 16 ACD patients during acute and remission phases, and 16 healthy volunteers.

RESULTS

Serum levels of adiponectin, chemokine (C-C motif) ligand 5 (CCL5), C-reactive protein (CRP), chitinase 3-like 1 (CHI3L1), complement factor D (CFD), endoglin, lipocalin-2, osteopontin, retinol-binding protein 4 (RBP4), and platelet factor 4 (PF4) were significantly higher, whereas levels of trefoil factor 3 (TFF3) were significantly lower, in ACD patients than in healthy controls. In ACD patients, serum levels of CCL5 were elevated, whereas levels of TFF3, soluble intercellular adhesion molecule-1 (sICAM-1), and platelet-derived growth factor (PDGF)-AB/BB were found to be lower during the remission phase of the disease.

CONCLUSIONS

Serum levels of adiponectin, CCL5, CRP, CHI3L1, CFD, endoglin, lipocalin-2, osteopontin, RBP4, PF4, and TFF3 might be exploited as biomarkers for ACD, whereas levels of CCL5, TFF3, sICAM-1, and PDGF-AB/BB might be exploited for evaluation of disease progression and efficacy of ACD treatment.

Delayed hypersensitivity reaction to intralesional triamcinolone acetonide following treatment for alopecia areata. Intradermal testing

BACKGROUND

Hypersensitivity reactions to intralesional corticosteroids are very rare and have been infrequently reported. Patch testing is considered the gold standard for diagnosing contact allergic dermatitis. However, intradermal testing is thought to be more accurate and sensitive in selected cases.

MAIN OBSERVATION

We describe a case of a delayed hypersensitivity reaction to intralesional triamcinolone acetonide following the treatment of alopecia areata. Patch testing to triamcinolone was negative but intradermal testing with a small volume of the same reagent elicited a strong reaction.

CONCLUSIONS

Patch testingmay be unsuccessful in detecting delayed reactions to intralesional corticosteroids. In such cases intradermal testing at a non-cosmetically sensitive sitemay be a useful diagnostic tool.

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

BACKGROUND

Cutaneous metal hypersensitivity reactions (MHR) are common but rare with implanted devices.

OBJECTIVES

This study aimed to characterize the opinions of dermatologists who are actively evaluating/advising patients with MHR.

METHODS

A questionnaire was distributed to all individuals who attended the European Society of Contact Dermatitis (ESCD) 2012 and the American Contact Dermatitis Society 2013 meetings.

RESULTS

A 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).

CONCLUSIONS

Metal hypersensitivity reactions consultation requests are common for preimplant and postimplant issues. Patch testing is currently the best test for MHR.

Patch testing in non-immediate drug eruptions

The present review addresses the literature regarding the sensitivity and specificity of the various diagnostic methods for evaluating non-immediate (ie, occurring more than 1 hour after drug administration) hypersensitivity reactions associated with β-lactams and other antibiotics, anticonvulsants, heparins, iodinated contrast media, etc. Such reactions include several clinical entities, which range from mild reactions, such as maculopapular rash and delayed-appearing urticaria, to severe ones, such as acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson syndrome, and toxic epidermal necrolysis (TEN). Clinical and laboratory studies indicate that a cell-mediated pathogenic mechanism is often involved in maculopapular rashes. However, this mechanism has also been demonstrated in other non-immediate reactions, such as urticarial and/or angioedematous manifestations, TEN, bullous exanthems, and AGEP. Patch tests, together with delayed-reading intradermal tests, lymphocyte transformation tests, and challenges, are useful tools for evaluating non-immediate drug eruptions. Patch tests can be performed with any form of commercial drugs and are safer than intradermal tests. However, patch tests are less sensitive than intradermal tests, and their sensitivity may vary, depending on the vehicle used.

Allergic contact dermatitis from corticosteroids: reproducibility of patch testing and correlation with intradermal testing

BACKGROUND

Corticosteroid contact allergy is not uncommon. The diagnosis can be made with either patch testing or intradermal (ID) testing. In view of a few problems that have been encountered with patch testing, patch testing is considered inferior to ID testing. The reported reproducibility of positive patch-test results in the literature ranges from 47 to 98%.

OBJECTIVES

This study was conducted to (1) determine the reproducibility of patch testing with topical steroid preparations and their clinical relevance, (2) correlate positive results with ID testing, (3) address the issue of cross-reactivity between different steroid groups, and (4) identify the percentage of positive reactions to preservatives and vehicles used in commercial topical steroids.

METHODS

A total of 19 patients with positive patch-test reactions to steroids from 1995 to 2004 were identified. Atopic patients and patients with type I hypersensitivity were excluded. The patients were patch-tested with a steroid series, select commercial steroid products, and vehicles and preservatives used in these preparations. The same patients were subjected to ID testing with select steroids. Readings were done on days 2, 5, and 7. ID testing was also performed on 9 control patients.

RESULTS

Tixocortol-21-pivalate is the most common steroid allergen (68%). The reproducibility of patch testing with topical steroid preparations ranged from 66 to 100%. Reactions to both ID testing and patch testing occurred in 16 patients (89%); 1 patient reacted to patch testing and 1 other reacted to ID testing. Formaldehyde and formaldehyde releasers accounted for the majority of reactions in the vehicles and preservatives group.

CONCLUSION

Patch testing is sufficient in diagnosing allergic contact dermatitis from topical steroids. Testing with commercial products is not a good screen for steroid allergy. The most common cross-reactions were between group A (hydrocortisone-type) corticosteroids and group D2 corticosteroids (composed of labile esters, with a long-chain ester at C17 and possibly C21).

Copper hypersensitivity: dermatologic aspects*

Reports of immune reactions of both the immediate and delayed types due to cutaneous or systemic exposure to copper have been reviewed, in the endeavor to draw a comprehensive profile of the immunogenic potential of that metal and its compounds. The metal's immunotoxic potential is also briefly reviewed. In principle, as noted for other transition metals, the electropositive copper ion is potentially immunogenic due to its ability to diffuse through biological membranes to form complexes in contact with tissue protein. Based on predictive guinea pig test and the local lymph node assay (LLNA), copper has a low sensitization potential. Reports of immune reactions to copper include immunologic contact urticaria (ICU), allergic contact dermatitis (ACD), systemic allergic reactions (SAR) and contact stomatitis (STO), but considering the widespread use of copper IUDs and the importance of copper in coinage, items of personal adornment and industry, unambiguous reports of sensitization to the metal are extremely rare, and even fewer are the cases, which appear clinically relevant. Reports of immune reactions to copper mainly describe systemic exposure from intrauterine devices and prosthetic materials in dentistry, implicitly excluding induction of the hypersensitivity from contact with the skin as a risk factor. We provide a diagnostic algorithm that might clarify the frequency of copper hypersensitivity.

Copper hypersensitivity: dermatologic aspects--an overview

Reports of immune hypersensitivity reactions of both the immediate and the delayed type following cutaneous or systemic exposure to copper are reviewed here in an endeavor to draw a comprehensive profile of the immunogenic potential of that metal and its compounds. The immunotoxic potential of the metal is also briefly reviewed. In principle, as noted for other transition metals, the electropositive copper ion is potentially immunogenic because of its ability to diffuse through biological membranes, forming complexes when in contact with tissue protein. Based on the results of the predictive guinea pig test and the local lymph node assay (LLNA), copper has a low sensitization potential. Reports of immune reactions to copper include immunologic contact urticaria (ICU), allergic contact dermatitis (ACD), systemic allergic reactions (SAR) and contact stomatitis (STO), but considering the widespread use of copper intrauterine devices (IUDs) and the importance of copper in coinage, items of personal adornment and industry, unambiguous reports of sensitization to the metal are extremely rare, and even fewer are the cases that appear clinically relevant. Most reports of immune reactions to copper describe systemic exposure as a cause--predominantly to intrauterine devices and to prosthetic materials in dentistry--implicitly excluding the induction of hypersensitivity from contact with the skin as a risk factor.

Patch testing to detect corticosteroid allergy: is it adequate?

Whilst patch testing with corticosteroids in ethanol is more sensitive than either petrolatum or the cream formulation, the frequency of false-negative reactions is not known. We have compared patch testing with corticosteroid at 1% in ethanol with intradermal (i.d.) tests using 1 mg corticosteroid suspended in normal saline. Patch tests with tixocortol pivalate and budesonide detected all patients allergic to hydrocortisone and budesonide, respectively. For other corticosteroids, the use of ethanol as a vehicle resulted in both false-positive and false-negative reactions. In particular, patch tests with hydrocortisone-17-butyrate missed 30% of all positive reactions detected by i.d. testing. There may be a case for advising the avoidance of this steroid in all patients who are positive on patch testing to tixocortol pivalate and budesonide.

Cutaneous-mucosal allergic contact reaction due to topical corticosteroids

We report the case of a 41-year-old nonatopic women with a previous history of eczematous reaction due to hydrocortisone who suffered worsening of her perennial rhinitis in association with perinasal dermatitis from the use of budesonide in nasal spray form, and stomatitis and pharyngitis due to budesonide in a bronchial inhaler. Patch tests with a series of 25 corticosteroids, some of them at different concentrations and in different vehicles, were positive to tixocortol pivalate, hydrocortisone, budesonide, prednisolone, hydrocortisone butyrate propionate, triamcinolone acetonide, and fluocinolone acetonide. For some of them, a 1% solution in ethanol gave a positive reaction when a 20% mixture in petrolatum did not. Like other authors, we suggest that some multiple positives may represent sensitization to several steroids independently, true cross-reactions, or both, and that ethanol is a better vehicle than petrolatum.

Delayed systemic allergic reactions to corticosteroids

From the limited number of reports in the literature, it would appear that various types of delayed reactions from systemically, intralesionally, and intra-articularly administered corticosteroids are rare, particularly given their widespread use. The purpose of this literature review is to summarize in table form the reported cases of generalized delayed systemic corticosteroid reactions with respect to patient presentation, methods of evaluation, and conclusions reached. In total, 24 cases of generalized delayed systemic corticosteroid reactions have been reported in the literature. Clinical presentation (timing and cutaneous manifestations) as well as evaluation of these patients has been variable; reactions reported include eczematous or exanthematous eruptions, with or without bullae or purpura. In 16 cases, the diagnoses have been supported by positive patch or intradermal testing. Overall, it appears that generalized delayed systemic reactions to corticosteroids show considerable variability and are infrequently reported. Patch and intradermal tests with standardized allergens appear to be the most useful tests currently available to support this clinical diagnosis.