Vesicant infusates are not associated with ultrasound-guided peripheral intravenous catheter failure: A secondary analysis of existing data.

BACKGROUND: Intravenous vesicants are commonly infused via peripheral intravenous catheters (PIVC) despite guidelines recommending administration via central route. The impact of these medications on PIVC failure is unclear. We aimed to assess dose-related impact of these caustic medications on ultrasound-guided (US) PIVC survivorship. METHODS: We performed a secondary analysis of a randomized control trial that compared survival of two catheters: a standard long (SL) and an ultra-long (UL) US PIVC. This study involved reviewing and recording all vesicants infusions through the PIVCs. Type and number of vesicants doses were extracted and characterized as one, two or multiple. The most commonly used vesicants were individually categorized for further analysis. The primary outcome was PIVC failure accounting for use and timing of vesicant infusates. RESULTS: Between October 2018 and March 2019, 257 subjects were randomized with 131 in the UL group and 126 in the SL group. Vesicants were infused in 96 (37.4%) out of 257 study participants. In multivariable time-dependent extended Cox regression analysis, there was no significant increased risk of failure due to vesicant use [adjusted hazard ratio, aHR 1.71 (95% CI 0.76-1.81) p = 0.477]. The number of vesicant doses was not significantly associated with the increased risk of PIVC failure [(1 vs 0) aHR 1.20 (95% CI 0.71-2.02) p = 0.500], [(2 vs 0) aHR 1.51 (95% CI 0.67-3.43) p = 0.320] and [(≥ 3 vs 0) aHR 0.98 (95% CI 0.50-1.92) p = 0.952]. CONCLUSION: Vesicant usage did not significantly increase the risk of PIVC failure even when multiple doses were needed in this investigation. Ultrasound-guided PIVCs represent a pragmatic option when vesicant therapy is anticipated. Nevertheless, it is notable that overall PIVC failure rates remain high and other safety events related to vesicant use should be considered when clinicians make vascular access decisions for patients.

Human risk assessment of inhaled irritants: Role of sensory stimulations from spatially separated nociceptors.

Contemporary approaches to human health risk assessment for respiratory tract irritants are variable and controversial. This manuscript provides an in-depth analysis and assessment of the applicability of the classical respiratory depression 50 % (RD50) assay with focus on the Log-linear extrapolation of the non-sensory irritant threshold (RD0 or RD10) relative to the contemporary Point of Departure (POD) U.S.-EPA benchmark approach. Three prototypic volatile chemically reactive irritants are used to exemplify the pros and cons of this alternative approach. These irritants differ in physicochemical properties affecting water-solubility and lipophilicity. Depending on these variables, a vapor may preferentially be retained in the extrathoracic region (ET), the tracheobronchial region (TB), and the pulmonary region (PU); although a smooth transition between these regions occurs at increasingly high concentrations. Each region has its specific nociceptors sensing irritants and regional-specific response to injury. The alternative approach using rats identified the chemical-specific critical region of respiratory tract injury. Statistically derived PODs on ET-TB related sensory irritation provide important information for ET-TB irritants but not for PU irritants. The POD of ET-TB irritants from acute and repeated studies decreased substantially. In summary, statistically derived PODs improve the risk assessment of respiratory tract irritants; however, those from repeated exposures should be given preference to those from acute exposures.

Pooled Results of Two Randomized Phase III Trials Evaluating VP-102, a Drug-Device Combination Product Containing Cantharidin 0.7% (w/v) for the Treatment of Molluscum Contagiosum.

BACKGROUND: Compounded cantharidin has been used for decades to treat molluscum contagiosum but lacks rigorous clinical evidence to support its safety and efficacy. VP-102 is a shelf-stable drug-device combination product that contains topical cantharidin (0.7% weight/volume [w/v]) and is being evaluated for the treatment of molluscum. OBJECTIVES: Our objective was to present pooled safety and efficacy analyses of VP-102 in the treatment of molluscum compared with vehicle. METHODS: Participants aged ≥ 2 years were randomized 3:2 to topical administration of VP-102 or vehicle in two randomized, double-blind, vehicle-controlled phase III trials. Study drug was applied to all baseline and new lesions once every 21 days until clear or for a maximum of four applications. Assessors blinded to treatment counted all lesions at each study visit. All adverse events (AEs) were documented. Data were pooled for analyses. RESULTS: In total, 310 participants received VP-102 and 218 received vehicle. Mean age was 7.5 years (range 2-60) for VP-102 and 6.8 (2-54) for vehicle. Complete clearance of all molluscum lesions at day 84 occurred in 50% of VP-102 participants and 15.6% of vehicle recipients (p < 0.0001). Mean molluscum lesion counts decreased 76% for VP-102 and 0.3% for vehicle at day 84 (p < 0.0001). The most common AEs in the VP-102 group were application site blistering, pruritus, pain, and erythema, which were generally mild or moderate in severity. CONCLUSIONS: Pooled analyses showed a significantly higher percentage of participants with complete molluscum lesion clearance and larger reductions in lesion counts with VP-102 than with vehicle. AEs were anticipated because of the pharmacodynamic properties of cantharidin. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT03377790 (first posted 19 December 2017) and NCT03377803 (first posted 19 December 2017). Video abstract: Pooled Results of Two Randomized Phase III Trials Evaluating VP 102, a Drug Device Combination Product Containing Cantharidin 0.7% (w/v) for the Treatment of Molluscum Contagiosum (MP4 131293 KB).

Human Induced Pluripotent Stem Cell-Based Skin for Assessing Transdermal Drug Permeability and Irritancy.

To establish a system for assessing drug permeation and irritation of the skin, the permeation of benzoic acid and isosorbide dinitrate, which are listed in the Pharmacopoeia, and the chemical irritation were evaluated using skin generated from human induced pluripotent stem cells (iPSCs). Multilayer structures and cellular markers (keratin 14 and 10, which are in basal and suprabasal epidermal layers) were clearly detected in our iPSC-based skin. Transepidermal water loss (TEWL) decreased after iPSC-derived keratinocytes were cultured on collagen gels from human primary fibroblasts. These results indicate that the barrier function was partly increased by formation of the living epidermis. The cumulative amount of benzoic acid and isosorbide dinitrate across human iPSC-based skin gradually increased after an initial lag time. Moreover, the irritancy of various chemicals (non-irritants: ultrapure water, allyl phenoxy-acetate, isopropanol, and hexyl salicylate and irritants: 5% sodium dodecyl sulfate (SDS), heptanal, potassium hydroxide (5% aq.) and cyclamen aldehyde) to iPSC-based skin was almost met the irritation criteria of the Organisation for Economic Co-operation and Development (OECD) guideline. The results of our iPSC-based skin evaluation provide useful basic information for developing an assessment system to predict the permeation and safety of new transdermal drugs in human skin.

A Phase 2 Open-Label Study to Evaluate VP-102 for the Treatment of Molluscum Contagiosum.

BACKGROUND: This Phase 2, open-label study evaluated the safety, efficacy, systemic exposure, and impact on quality of life (QoL) with treatment using VP-102, a drug-device combination containing cantharidin (0.7% w/v) in subjects with molluscum contagiosum (MC). STUDY DESIGN: Pediatric subjects with MC (2–15 years of age) were eligible to enroll in this 12-week study. MC lesions were treated topically with VP-102 every 21 days until clearance (maximum of 4 treatments). Adverse events (AEs) and QoL outcomes (using the Children's Quality of Life Index, CDLQI) were documented at each visit. Rate of complete clearance and the percent reduction in lesions were measured at each visit on days 21, 42, 63, and 84 (end of study [EOS] visit). A group of 17 subjects with at least 21 MC lesions was evaluated for systemic cantharidin exposure via plasma samples obtained before the first application of VP-102, and at 2 hours, 6 hours, and 24 hours post-application. RESULTS: A total of 33 subjects enrolled in the study (n=17 systemic exposure group, n=16 standard group). There were an equal number of male and female subjects. Subject mean (SD, range) age was 6.7 (3.3, 2–15) years, with a mean lesion count of 30 (26.1, 3–113). Complete lesion clearance was achieved in 48.5% of subjects, with a 90.4% reduction in lesions from baseline to the EOS visit. Mean CDLQI score decreased from 2.6 at baseline to 0.38 at the EOS visit. AEs were mild to moderate in severity and expected due to the pharmacodynamic action of cantharidin. There were no serious treatment-related adverse events and no study discontinuations due to treatment. In the systemic exposure group plasma cantharidin levels were below the lower limit of quantitation (LLOQ, 2.5 ng/mL) in 65 of 66 samples. CONCLUSIONS: VP-102 treatment resulted in a reduction in lesion counts and improved QoL. Treated subjects had a 48.5% rate of complete clearance of molluscum lesions. Negligible systemic cantharidin exposure was observed in the systemic exposure group. This data demonstrates safety and efficacy of treatment with VP-102 in MC; a widespread viral infection that does not have any current FDA-approved treatments. Significant Finding: Treatment of subjects with MC using VP-102 resulted in negligible systemic cantharidin exposure, as well as a reduction in lesion counts, improved QoL, and a demonstrated efficacy in clearance of new and baseline MC lesions. Meaning: Results of this Phase 2 study demonstrate efficacy and safety outcomes in using VP-102 in MC subjects, and large randomized clinical trials are warranted to compare topical VP-102 with a vehicle control in order to fully evaluate the use of the medication. ClinicalTrials.gov identifier: NCT03186378 J Drugs Dermatol. 2021;20(1):70-75. doi:10.36849/JDD.5626.

A comparative study between the two patch test systems Finn chambers and Finn chambers AQUA.

BACKGROUND: Finn Chambers AQUA (FCA) is a development of the Finn Chambers (FC) test system in which the test chambers are mounted on a moisture-resistant adhesive patch. FCA has pre-fixed filter papers. Because the use of FCA does not require any extra taping or use of separate filter papers, a change from FC to FCA chambers may be beneficial for both patients and patch test technicians. OBJECTIVES: To investigate whether there are any differences regarding detection of contact allergy when simultaneous patch testing is performed with FC and FCA. MATERIALS AND METHODS: Results from 434 dermatitis patients simultaneously tested with 10 allergens in both FC and FCA were evaluated. RESULTS: There were no significant differences regarding detection of positive reactions between the two test systems. There were significantly more doubtful reactions to methylisothiazolinone, fragrance mix I and hydroperoxides of linalool when testing with FCA. We only observed significantly more doubtful reactions in FC regarding nickel(II)sulfate. Irritant reactions to formaldehyde were also significantly more common when using FCA. CONCLUSION: The FC and FCA had good agreement in detection of positive reactions. However, the results including doubtful and irritant reactions justify further research regarding optimization of the dose.

Hand hygiene during COVID-19: Recommendations from the American Contact Dermatitis Society.

The recent COVID-19 pandemic has resulted in increased hand hygiene and hand cleansing awareness. To prevent virus transmission, the Centers for Disease Control and Prevention recommends frequent hand washing with soap and water. Hand hygiene products are available in a variety of forms, and while each of these formulations may be effective against COVID-19, they may also alter skin barrier integrity and function. As health care workers and the general population focus on stringent hand hygiene, the American Contact Dermatitis Society anticipates an increase in both irritant contact and allergic contact hand dermatitis. Alcohol-based hand sanitizers with moisturizers have the least sensitizing and irritancy potential when compared to soaps and synthetic detergents. This article provides an overview of the most frequently used hand hygiene products and their associations with contact dermatitis as well as recommendations from the American Contact Dermatitis Society on how to treat and prevent further dermatitis.

Individual differences in the perception of orthonasal irritation induced by food.

Oral responsiveness to the burning/spicy sensation affects food behaviors and diet; therefore, it is reasonable to hypothesize that the variation in nasal responsiveness to irritant foods may play a role in modulating food behaviors. This study explored the variation among individuals in orthonasal irritation induced by smelling food ingredients containing irritant compounds: mustard oil (2.0, 10.0, and 100.0% v/v mustard oil in corn oil; irritant compound: allyl isothiocyanate); vinegar (3.5, 42.3, and 98.6% v/v vinegar in water; irritant compound: acetic acid); and wasabi (0.1, 0.2, and 0.4% w/w wasabi powder in water; irritant compound: allyl isothiocyanate). Sixty-eight subjects (40% males; 19-87 years) smelled the nine samples and rated their perceived intensity of odor, irritation and liking. Wide individual variation in the perception of irritation and odor intensity was found, especially at the highest concentrations. Young individuals were the most sensitive to all stimuli. No significant differences were found between males and females. Fifty-seven percent of subjects were "HYPO" and 43 percent "HYPER" responsive to irritation, respectively. Perceived irritation was positively correlated with odor intensity and tended to be negatively correlated with liking, especially in familiar stimuli. The results suggest that the variation in nasal responsiveness to irritant foods may contribute to influencing food acceptance and therefore, to modulating food behaviors.

Diagnostic approach to occupational rhinitis: the role of nasal provocation tests.

PURPOSE OF REVIEW: The diagnosis of occupational rhinitis is a challenge. Underdiagnosis is substantial as the clinical presentation is nonspecific and often no occupational history is taken. Detection of occupational rhinitis can be improved by including screening questions on occupational exposure in the assessment of every patient with adult-onset rhinitis. RECENT FINDINGS: Case reports, case series and epidemiological studies continuously demonstrate new sensitizers and irritants capable of inducing allergic or nonallergic (irritant-induced) occupational rhinitis. Recent reviews have focused on the value of immunological tests with specific IgE, skin prick tests or basophil activation tests in demonstrating sensitization to occupational agents. Nasal provocation tests (NPT) can establish a definite diagnosis of allergic occupational rhinitis. Several NPT guidelines have been published, however, focusing exclusively on standardized high-molecular weight allergens. When performing NPT with nonstandardized agents -- like most occupational sensitizers -- adapted protocols are needed. SUMMARY: We provide pragmatic guidance to clinicians taking care of rhinitis patients on how to diagnose occupational rhinitis, based on recent insights from the literature. We focus on the challenges in the diagnostic work-up, on how to identify suspected causes, and on the role of NPT.

Ethyl acrylate: influence of sex or atopy on perceptual ratings and eye blink frequency.

Occupational exposure limits (OELs) are derived for protection from health hazards, assuming that exposed subjects are healthy adult workers. Whether differences in susceptibility to sensory irritation effects from airborne chemicals have to be taken into account is currently under discussion. Thus, we chose atopics as a healthy but possibly susceptible subpopulation that can be identified with a clinical test. To investigate the influence of sex or atopy on sensitivity to airborne chemicals, 22 subjects were exposed for 4 h to ethyl acrylate at three concentrations: 0.05 ppm (odor threshold; sham), 5 ppm (constant), and varying exposure between 0 and 10 ppm. Odor intensity decreased and eye irritation ratings increased in a dose-dependent manner, reflecting the time course of the exposure scenarios. The reports of moderate-to-strong eye irritation were verified by significant increases in eye blink frequency. Our results show that women reported subjective eye irritation to an increasing degree. However, these sex-related differences in ratings could not be verified by objective assessment of eye blink frequency. Atopic subjects reported higher odor intensity than non-atopic subjects, but only during the sham (odorous but not irritating) exposure condition. Differences in ratings on annoyance, and eye or nose irritation were not found. Furthermore, the study revealed that atopic subjects might belong to a group of subjects with frequent eye blink activity. Although the relative increase in blink rates was more pronounced in non-atopic subjects, atopic subjects had significant higher blink rates at the end of the exposure to varying ethyl acrylate concentrations. Our results do not support that atopy enhances chemosensory effects if only the increase of blink rates and not the absolute height are considered as adverse effect. Nevertheless, the results indicate that individuals with frequent eye blink activity should be distinguished from those with normal eye blink activity while investigating blink rates as objective parameter of eye irritation.

Ethanolamines permeate slowly across human skin ex vivo, but cause severe skin irritation at low concentrations.

Skin exposures are common during cleaning activities, and may contribute to the overall body burden. Cleaning products may contain irritants such as monoethanolamine (MEA) and diethanol amine (DEA). The significance of the skin exposure route is unknown, as no estimates for MEA skin permeation are available. We used in vitro flow-through diffusion cells with excised fresh human skin to measure skin permeation, and assessed skin damage with histological methods. MEA(aq) by itself (2%) or as a constituent in cleaning products (0.25% working solution) did not permeate after 1 h or 24 h of exposure. MEA(aq) (10%) did not permeate skin after 1 h but after 24 h with a delay (Tlag; 7 h) and a moderate permeation rate (J; 26.6 µg/cm2/h). MEA permeation rate was 20-fold greater (544 µg/cm2/h) and » of the time lag (1.5 h) when applied as undiluted cleaning product (13% MEA) compared to 10% MEA(aq). DEA in cleaning products did not permeate skin after 24 h. MEA and DEA produced skin irritations at low concentrations (1% MEA) and severe skin irritations when tested as a constituent in cleaning products. Absorption increased from 0 to 3% after 24 h to 14-29% after 88 h of MEA exposure, and is likely explained by the increased damage of the skin barrier. Limitations of this study are the low number of skin donors (N = 5) available. Our results demonstrate that topically applied MEA permeates across human skin relatively slowly and not below 5% while relatively extensively as a constituent of a commercial cleaning product.

Biodegradable Thermosensitive PLGA-PEG-PLGA Polymer for Non-irritating and Sustained Ophthalmic Drug Delivery.

Challenges of ophthalmic drug delivery arise from not only the limited solubility of hydrophobic therapeutics, but also the restricted permeability and fast clearance of drugs due to the complex anatomy and physiology of the eyes. Biodegradable thermosensitive polymer, poly(dl-lactide-co-glycolide-b-ethylene glycol-b-dl-lactide-co-glycolide) (PLGA-PEG-PLGA) is a desirable ophthalmic drug delivery system because it can be formulated into injectable solution which forms gel in situ to provide prolonged drug release. In this study, excellent biocompatibility of blank PLGA-PEG-PLGA (1800-1500-1800) thermogel was demonstrated with insignificant difference from saline noted in rat eye enucleation test, in vivo inflammation test upon topical instillation, and subconjunctival injection. After subconjunctival injection, thermogel formulations loaded with hydrophilic (rhodamine B) or hydrophobic (coumarin 6) fluorescent dyes were retained up to 4 weeks in eye tissues and significantly higher level was detected than rhodamine B solution or coumarin 6 suspension in weeks 3 and 4. Moreover, in vivo whole body imaging showed that dye-loaded (sulfo-cyanine 7 NHS ester, Cy7; or cyanine 7.5 alkyne, Cy7.5) thermogels had longer retention at the injection site and retarded release to other body parts than dye solutions. Generally, the release rate of hydrophobic dyes (coumarin 6 and Cy7.5) was much slower than that of the hydrophilic dyes (rhodamine B and Cy7) from the thermogel. In summary, the thermogel was safe for ophthalmic drug delivery and could deliver both hydrophobic and hydrophilic compounds for sustained drug release into eye tissues with single subconjunctival injection for better patient compliance and reduced risks on repeated injection.

Salicylic acid amplifies Carbachol-induced bronchoconstriction in human precision-cut lung slices.

BACKGROUND: Asthma exacerbations evoke emergency room visits, progressive loss of lung function and increased mortality. Environmental and industrial toxicants exacerbate asthma, although the underlying mechanisms are unknown. We assessed whether 3 distinct toxicants, salicylic acid (SA), toluene diisocyanate (TDI), and 1-chloro-2,4-dinitrobenzene (DNCB) induced airway hyperresponsiveness (AHR) through modulating excitation-contraction coupling in human airway smooth muscle (HASM) cells. The toxicants include a non-sensitizing irritant (SA), respiratory sensitizer (TDI) and dermal sensitizer (DNCB), respectively. We hypothesized that these toxicants induce AHR by modulating excitation-contraction (EC) coupling in airway smooth muscle (ASM) cells. METHODS: Carbachol-induced bronchoconstriction was measured in precision-cut human lung slices (hPCLS) following exposure to SA, TDI, DNCB or vehicle. Culture supernatants of hPCLS were screened for mediator release. In HASM cells treated with the toxicants, surrogate readouts of EC coupling were measured by phosphorylated myosin light chain (pMLC) and agonist-induced Ca2+ mobilization ([Ca2+]i). In addition, Nrf-2-dependent antioxidant response was determined by NAD(P) H quinone oxidoreductase 1 (NQO1) expression in HASM cells. RESULTS: In hPCLS, SA, but not TDI or DNCB, potentiated carbachol-induced bronchoconstriction. The toxicants had little effect on release of inflammatory mediators, including IL-6, IL-8 and eotaxin from hPCLS. In HASM cells, TDI amplified carbachol-induced MLC phosphorylation. The toxicants also had little effect on agonist-induced [Ca2+]i. CONCLUSION: SA, a non-sensitizing irritant, amplifies agonist-induced bronchoconstriction in hPCLS via mechanisms independent of inflammation and Ca2+ homeostasis in HASM cells. The sensitizers TDI and DNCB, had little effect on bronchoconstriction or inflammatory mediator release in hPCLS. IMPLICATIONS: Our findings suggest that non-sensitizing irritant salicylic acid may evoke AHR and exacerbate symptoms in susceptible individuals or in those with underlying lung disease.

Cough responses to inhaled irritants are enhanced by eosinophil major basic protein in awake mice.

A distinct association between airway eosinophilia and chronic cough is well documented. Eosinophil granule-derived cationic proteins, such as major basic protein (MBP), have been shown to activate and enhance the excitability of bronchopulmonary C-fiber sensory nerves, which may then lead to an increase in cough sensitivity. This study was carried out to determine whether cough responses to inhaled irritant gases were altered by delivery of MBP into the airways. An awake mouse moved freely in a recording chamber that was ventilated with a constant flow of air or irritant gas mixture. Cough responses to separate inhalation challenges of sulfur dioxide (SO2; 300 and 600 ppm) and ammonia (NH3; 0.1 and 0.2%), each for 5-min duration, were measured daily for 3 days before and for up to 8 days after MBP (10-20 µg) instillation into the trachea. During control, inhalations of SO2 and NH3 consistently elicited cough responses in a dose-dependent manner. After MBP treatment, cough responses to both SO2 and NH3 increased significantly and progressively and reached peaks 2-3 days after the treatment before returning to control level in 3-7 days. In sharp contrast, cough responses to these irritant gases were not affected by the treatment with the vehicle of MBP. These results suggest that the MBP-induced lingering elevation of cough responsiveness may be a contributing factor in the pathogenesis of chronic cough associated with eosinophilic infiltration of the airways.

Down-regulation of the inflammatory response after short-term exposure to low levels of chemical vapours.

OBJECTIVE: To investigate the relation between signs and symptoms of irritation and biomarkers of inflammatory markers in blood in healthy volunteers exposed to different chemical vapours for 2 or 4 hours in an exposure chamber. METHODS: The investigated chemicals were: acetic acid (5 and 10 ppm), acrolein (0.05 and 0.1 ppm), 1,4-dioxane (20 ppm), n-hexanal (2 and 10 ppm), hydrogen peroxide (0.5 and 2.2 ppm), 2-propanol (150 ppm), m-xylene (50 ppm), standard and dearomatised white spirit (100 and 300 mg/m3). C reactive protein (CRP), serum amyloid A protein and interleukin 6 were measured in plasma immediately before and 2 or 4 hours after the exposures. Symptoms were rated from 0 to 100 mm in Visual Analogue Scales and covered 10 questions whereof four related to irritation: discomfort in the eyes, nose and throat and dyspnoea. The effect measurements included blink frequency by electromyography, nasal swelling by acoustic rhinometry and lung function by spirometry. RESULTS: Logistic quantile regression analyses revealed no significant associations except a negative relation between ratings of irritation and CRP. CONCLUSION: The results suggest a down-regulation of CRP after short-term exposure to low levels of vapours of irritating chemicals. This response might be mediated by the cholinergic anti-inflammatory pathway and further studies are recommended in order to refute or confirm this hypothesis.

Pustular DRESS Syndrome Secondary to Hydroxychloroquine With EBV Reactivation

Background: Drug reaction with eosinophilia and systemic symptoms (DRESS syndrome) or drug-induced hypersensitivity (DIHS) is a rare and feared complication of frequently used medications such as anticonvulsants, sulfonamides, and allopurinol. To date, no reports of hydroxychloroquine-induced pustular DRESS syndrome have been associated with Epstein-Barr virus (EBV) reactivation nor imitated other cutaneous adverse drug reactions as in our patient. Observation: A 56-year-old female presented with a diffuse cutaneous eruption involving the face, trunk, extremities, and palms approximately two weeks after the initiation of hydroxychloroquine therapy for a suspected Sjögren's-like process with inflammatory cervical lymphadenopathy. Skin examination demonstrated diffuse erythematous and edematous papules and pustules on her dorsal and volar hands and fingers, arms, legs, chest, abdomen, back, scalp, and face. In many areas, lesions coalesced into plaques with overlying pustules, scale, and crust. Additional notable exam findings included centralized facial edema, edema of the hands, and cervical lymphadenopathy. Laboratory workup revealed leukocytosis, peripheral eosinophilia, elevated transaminases, and a negative autoimmune workup; however, serology demonstrated EBV reactivation. Histologic assessment displayed a spongiotic dermatitis with eosinophils, superficial perivascular dermatitis, as well as corneal, subcorneal, and intraepidermal neutrophilic microabscesses, mimicking acute generalized exanthematous pustulosis or pustular psoriasis, even though clinical evaluation suggested DRESS syndrome. Conclusion: To our knowledge, this is the first reported case of hydroxychloroquine-induced pustular DRESS syndrome in the context of EBV reactivation. Given hydroxychloroquine's immunomodulatory function and association with other cutaneous manifestations, our patient represents a significant diagnostic challenge. Therefore, this case highlights the importance of knowledge regarding overlapping features, histologically and clinically, among acute generalized exanthematous pustulosis, pustular psoriasis, and DRESS syndrome. J Drugs Dermatol. 2019;18(2):207-209.

Thermography: High sensitivity and specificity diagnosing contact dermatitis in patch testing.

BACKGROUND: Patch testing of contact allergens to diagnose allergic contact dermatitis (ACD) is a traditional, useful tool. The most important decision is the distinction between allergic and irritant reactions, as this has direct implications on diagnosis and management. Our objective was to evaluate a new method of non-contact infrared reading of patch tests. Secondary objectives included a possible correlation between the intensity of the patch test reaction and temperature change. METHODS: 420 positive reactions from patients were included in our study. An independent patch test reader assessed the positive reactions and classified them as allergic (of intensity + to +++) or irritant (IR). At the same time, a forward-looking infrared (FLIR) camera attachment for an iPhone was used to acquire infrared thermal images of the patch tests, and images were analyzed using the FLIR ONE app. RESULTS: Allergic patch test reactions were characterized by temperature increases of 0.72 ± 0.67 °C compared to surrounding skin. Irritant reactions only resulted in 0.17 ± 0.31 °C temperature increase. The mean temperature difference between the two groups was highly significant (p < 0.0001) and therefore was used to predict the type of contact dermatitis. CONCLUSIONS: Thermography is a reliable and effective way to distinguish between allergic and irritant contact dermatitis.

Efficacy of meloxicam in a pain model in sheep.

OBJECTIVE: To evaluate the efficacy of the non-steroidal anti-inflammatory drug, meloxicam, in alleviating pain and inflammation and on production-related variables in a model of sterile acute inflammation in sheep. METHODS: Groups of 12 mature Merino ewes received 0, 0.5, 1.0 or 1.5 mg/kg meloxicam subcutaneously 90 min before injection of 0.1 mL turpentine subcutaneously on the anterior aspect of the proximal phalanx of a forelimb. Pain- and inflammation-related variables were assessed at -18, 3, 6, 9, 12, 24, 48 and 72 h relative to meloxicam administration. Daily feed intake and body weight change 7 days later were also assessed. Pain-related variables measured were weight borne on each forelimb, lameness score, time each forelimb was raised in a 20-s interval and tolerance to a noxious mechanical stimulus. Inflammation-related variables measured were skin temperature, limb circumference, body temperature, plasma haptoglobin concentration and peripheral blood leucocyte parameters. RESULTS: Meloxicam was effective in improving all pain-related variables. A dose-dependent response was seen between 0 and 1.0 mg/kg, with no additional benefit provided by 1.5 mg/kg. At a dose rate of 1.0 mg/kg, meloxicam improved weight borne on the turpentine-treated limb by 14%, reduced the time the treated limb was held in a non-weight-bearing posture by 46%, reduced the lameness score by 58% and improved tolerance to pressure by 52%. No significant effects of meloxicam on inflammatory variables or appetite were observed. CONCLUSIONS: Using a validated pain model, the data suggested that 1.0 mg/kg meloxicam provided significant analgesic benefits to sheep.

Non-invasive dural stimulation in mice: A novel preclinical model of migraine.

BACKGROUND: Migraine is characterized by a collection of neurological symptoms in the absence of injury or damage. However, several common preclinical migraine models require significant damage to the skull to stimulate the dura mater, the likely source of afferent signaling leading to head pain. The goal of this study was to determine whether dural stimulation can be performed in mice using an injection that does not cause injury or damage. METHODS: Using mice, injections of stimuli were administered to the dura mater through the soft tissue at the intersection between the lambdoidal and sagittal sutures. This technique did not require a permanent cannula nor did it cause damage to the skull or dura. Following injection of noxious stimuli, migraine-like behaviors were measured including cutaneous allodynia and facial grimace. The retrograde tracer fluorogold was applied onto the dura using the same injection technique to label trigeminal ganglion cell bodies, which were then testing in vitro using patch-clamp electrophysiology. RESULTS: Dural injection of allyl-isothiocyanate, low pH, interleukin-6, or inflammatory soup but not vehicles, led to cephalic/extracephalic allodynia. Facial grimace responses were also observed with allyl-isothiocyanate, pH 6.0, and interleukin-6. Stimulation with interleukin-6 causes priming to normally subthreshold pH 7.0 stimulation of the dura following resolution of the initial interleukin-6 behavior. Systemic injection of sumatriptan at the time of dural stimulation with inflammatory soup decreased the resulting cutaneous hypersensitivity. Trigeminal ganglion cell bodies retrogradely labeled from the dura had low pH-evoked currents similar to those generated by acid-sensing ion channels. CONCLUSION: Non-invasive dural stimulation in mice can be used as a model of migraine in the absence of injury.