Pruritus in burns: review article

Altered resting-state functional brain activity in patients with chronic post-burn pruritus

BACKGROUND

Pruritus, a common symptom of burn wounds, arises from skin tissue damage and abnormal tissue healing. Chronic post-burn pruritus (CPBP) is defined as itching that persists for six weeks or more. The brain mechanisms underlying CPBP are not understood adequately. This study aims to explore abnormal brain function in CPBP patients and identify potential pathogenesis of pruritus.

MATERIALS AND METHODS

Twenty patients with CPBP and twenty healthy controls (HCs) participated in the study and underwent resting-state functional magnetic resonance imaging (fMRI) scans. Brain activity was evaluated using regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and fractional ALFF (fALFF) measures. Preprocessing of fMRI data involved steps such as slice timing correction, motion correction, and nuisance regression to account for physiological noise and head motion. Statistical analyses included two-sample t-tests to compare ReHo, ALFF, and fALFF values between CPBP patients and HCs, with age as a covariate, and Spearman correlation analysis to explore relationships between brain activity measures and clinical characteristics.

RESULTS

The study revealed significant differences in brain activity between CPBP patients and HCs. CPBP patients exhibited altered higher ReHo in regions including the bilateral middle frontal gyrus, medial superior frontal gyrus, precuneus, left insula, right caudate, and bilateral cerebellar tonsils, with decreased ReHo in the right precentral gyrus. ALFF analysis showed increased activity in the bilateral middle frontal gyrus, medial superior frontal gyrus, right precuneus, and right inferior frontal gyrus, and decreased ALFF in the left precentral gyrus and right postcentral gyrus. fALFF values were notably higher in the bilateral medial superior frontal gyrus and precuneus. Several brain regions with significant differences in ReHo, ALFF, and fALFF were extensively correlated with the burned area and pruritus scale scores.

CONCLUSION

Our data suggest that patients with CPBP show alterations in ReHo, ALFF, and fALFF values primarily in brain regions associated with the default mode network and sensorimotor areas. These results may provide valuable insights relevant to the neuropathology of CPBP.

Effectiveness of Postburn Pruritus Treatment and Improvement of Insomnia-A Randomized Trial

Postburn pruritus is difficult to assess and treat. Antihistamines used in its treatment provide little relief. Identification of the itch neuronal pathway has inspired new alternatives, including gabapentin, for its management. The study compared the effectiveness of cetirizine, gabapentin, and a combination of gabapentin and cetirizine in treating postburn pruritus. Burn patients were randomly assigned to treatment with Cetirizine (n = 23), Gabapentin (n = 23), or Cetirizine plus Gabapentin (n = 23). A baseline assessment of the intensity or the severity of pruritus was evaluated, after which treatment commenced with standard doses of the 3 study regimens. Quality of sleep was assessed at baseline (day 0) and repeated on day 3, day 7, and day 14. Approximately 97% of participants presented with moderate or severe itch; 69% with acute itch; and the majority (94.2%) experienced pruritus between the first and fourth weeks. Gabapentin reduced itch by 92.9% in 14 days compared to cetirizine's 61.8%. The combined effect of cetirizine and gabapentin was comparable using gabapentin alone. When the itch became protracted over 6 weeks, the effectiveness of cetirizine in controlling itch worsened. It reduced itch intensity by only 37.7%, whilst gabapentin did so at 89.4%. Itch intensity correlated positively with insomnia, and controlling itch intensity improved sleep. Gabapentin was more effective for the treatment of postburn pruritus than cetirizine. Controlling itch intensity improved sleep. In acute and moderate itch, low-dose gabapentin could be added if cetirizine is the drug intended for its treatment.

Interventions for postburn pruritus

BACKGROUND

Postburn pruritus (itch) is a common and distressing symptom experienced on healing or healed burn or donor site wounds. Topical, systemic, and physical treatments are available to control postburn pruritus; however, it remains unclear how effective these are.

OBJECTIVES

To assess the effects of interventions for treating postburn pruritus in any care setting.

SEARCH METHODS

In September 2022, we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus. We also searched clinical trials registries and scanned references of relevant publications to identify eligible trials. There were no restrictions with respect to language, publication date, or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that enrolled people with postburn pruritus to compare an intervention for postburn pruritus with any other intervention, placebo or sham intervention, or no intervention.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 25 RCTs assessing 21 interventions with 1166 randomised participants. These 21 interventions can be grouped into six categories: neuromodulatory agents (such as doxepin, gabapentin, pregabalin, ondansetron), topical therapies (such as CQ-01 hydrogel, silicone gel, enalapril ointment, Provase moisturiser, beeswax and herbal oil cream), physical modalities (such as massage therapy, therapeutic touch, extracorporeal shock wave therapy, enhanced education about silicone gel sheeting), laser scar revision (pulsed dye laser, pulsed high-intensity laser, fractional CO2 laser), electrical stimulation (transcutaneous electrical nerve stimulation, transcranial direct current stimulation), and other therapies (cetirizine/cimetidine combination, lemon balm tea). Most RCTs were conducted at academic hospitals and were at a high risk of performance, attrition, and detection bias. While 24 out of 25 included studies reported change in burn-related pruritus, secondary outcomes such as cost-effectiveness, pain, patient perception, wound healing, and participant health-related quality of life were not reported or were reported incompletely. Neuromodulatory agents versus antihistamines or placebo There is low-certainty evidence that doxepin cream may reduce burn-related pruritus compared with oral antihistamine (mean difference (MD) -2.60 on a 0 to 10 visual analogue scale (VAS), 95% confidence interval (CI) -3.79 to -1.42; 2 studies, 49 participants). A change of 2 points represents a minimal clinically important difference (MCID). Due to very low-certainty evidence, it is uncertain whether doxepin cream impacts the incidence of somnolence as an adverse event compared to oral antihistamine (risk ratio (RR) 0.64, 95% CI 0.32 to 1.25; 1 study, 24 participants). No data were reported on pain in the included study. There is low-certainty evidence that gabapentin may reduce burn-related pruritus compared with cetirizine (MD -2.40 VAS, 95% CI -4.14 to -0.66; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that gabapentin reduces the incidence of somnolence compared to cetirizine (RR 0.02, 95% CI 0.00 to 0.38; 1 study, 40 participants). No data were reported on pain in the included study. There is low-certainty evidence that pregabalin may result in a reduction in burn-related pruritus intensity compared with cetirizine with pheniramine maleate (MD -0.80 VAS, 95% CI -1.24 to -0.36; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that pregabalin reduces the incidence of somnolence compared to cetirizine (RR 0.04, 95% CI 0.00 to 0.69; 1 study, 40 participants). No data were reported on pain in the included study. There is moderate-certainty evidence that ondansetron probably results in a reduction in burn-related pruritus intensity compared with diphenhydramine (MD -0.76 on a 0 to 10 numeric analogue scale (NAS), 95% CI -1.50 to -0.02; 1 study, 38 participants). A change of 2 points represents a MCID. No data were reported on pain and adverse events in the included study. Topical therapies versus relevant comparators There is moderate-certainty evidence that enalapril ointment probably decreases mean burn-related pruritus compared with placebo control (MD -0.70 on a 0 to 4 scoring table for itching, 95% CI -1.04 to -0.36; 1 study, 60 participants). No data were reported on pain and adverse events in the included study. Physical modalities versus relevant comparators Compared with standard care, there is low-certainty evidence that massage may reduce burn-related pruritus (standardised mean difference (SMD) -0.86, 95% CI -1.45 to -0.27; 2 studies, 166 participants) and pain (SMD -1.32, 95% CI -1.66 to -0.98). These SMDs equate to a 4.60-point reduction in pruritus and a 3.74-point reduction in pain on a 10-point VAS. A change of 2 VAS points in itch represents a MCID. No data were reported on adverse events in the included studies. There is low-certainty evidence that extracorporeal shock wave therapy (ESWT) may reduce burn-related pruritus compared with sham stimulation (SMD -1.20, 95% CI -1.65 to -0.75; 2 studies, 91 participants). This equates to a 5.93-point reduction in pruritus on a 22-point 12-item Pruritus Severity Scale. There is low-certainty evidence that ESWT may reduce pain compared with sham stimulation (MD 2.96 on a 0 to 25 pressure pain threshold (PPT), 95% CI 1.76 to 4.16; 1 study, 45 participants). No data were reported on adverse events in the included studies. Laser scar revision versus untreated or placebo controls There is moderate-certainty evidence that pulsed high-intensity laser probably results in a reduction in burn-related pruritus intensity compared with placebo laser (MD -0.51 on a 0 to 1 Itch Severity Scale (ISS), 95% CI -0.64 to -0.38; 1 study, 49 participants). There is moderate-certainty evidence that pulsed high-intensity laser probably reduces pain compared with placebo laser (MD -3.23 VAS, 95% CI -5.41 to -1.05; 1 study, 49 participants). No data were reported on adverse events in the included studies.

AUTHORS' CONCLUSIONS

There is moderate to low-certainty evidence on the effects of 21 interventions. Most studies were small and at a high risk of bias related to blinding and incomplete outcome data. Where there is moderate-certainty evidence, practitioners should consider the applicability of the evidence for their patients.

Scars

Wound healing occurs as a response to disruption of the epidermis and dermis. It is an intricate and well-orchestrated response with the goal to restore skin integrity and function. However, in hundreds of millions of patients, skin wound healing results in abnormal scarring, including keloid lesions or hypertrophic scarring. Although the underlying mechanisms of hypertrophic scars and keloid lesions are not well defined, evidence suggests that the changes in the extracellular matrix are perpetuated by ongoing inflammation in susceptible individuals, resulting in a fibrotic phenotype. The lesions then become established, with ongoing deposition of excess disordered collagen. Not only can abnormal scarring be debilitating and painful, it can also cause functional impairment and profound changes in appearance, thereby substantially affecting patients' lives. Despite the vast demand on patient health and the medical society, very little progress has been made in the care of patients with abnormal scarring. To improve the outcome of pathological scarring, standardized and innovative approaches are required.

Serial Casting as an Effective Method for Burn Scar Contracture Rehabilitation: A Case Series

Guidelines and protocols for orthoses in burn scar contracture rehabilitation are limited. The current study aims to determine the optimal frequency of casting, potentially facilitating the development of a serial casting protocol. Previous literature supporting casting has low generalizability due to methodology limitations. Seven patients with burn scar contracted joints, who did not respond to traditional therapy, were recruited in this study. Patients were serially casted once, three times, or five times a week. Joint range of motion was maximized with stretching and exercise techniques before every new cast application. Across all patients, active range of motion increased from 65.8 ± 27.8° to 108.1 ± 23.3° with casting; or from 57.8 ± 16.2% to 96.7 ± 2.9% of normal. Similarly, scars improved from 9.5 ± 1.5 to 4.9 ± 1.4 on the Modified Vancouver Scar Scale score. This therapeutic effect was achieved within an average of 8.5 ± 3.7 d and 4.0 ± 2.2 new cast applications. Given the study findings, the procedures outlined could be used to develop a standardized serial casting protocol for burn scar contracture rehabilitation.

No indications for altered EEG oscillatory activity in patients with chronic post-burn itch compared to healthy controls

A large proportion of patients with burn injuries develop chronic itch, which impacts quality of life. The underlying pathophysiological mechanisms are poorly understood. This cross-sectional pilot study investigates whether altered cortical oscillatory processes are involved in chronic post-burn itch. Continuous electroencephalography (EEG) data were recorded during rest and stimulation of non-injured skin, inducing itch (histamine and electrical) and cold-pressor task pain for 15 adults with chronic post-burn itch and 15 matched healthy controls. Quantitative metrics comprised oscillatory power and peak frequencies in theta, alpha, and beta bands. No statistical differences between patients and healthy controls were found in oscillatory activity during rest or stimulation, with Bayesian analysis suggesting equivocal evidence. However, post-traumatic stress symptoms and duration of chronic itch may be associated with changes in oscillatory activity. A lack of differences in cortical oscillatory processing and itch levels at non-injured sites, suggests that itch symptoms have a localised character in this sample of patients with post-burn itch. For future studies, a biopsychological approach with integration of peripheral and central nervous system techniques, linear and non-linear EEG analysis, injured and non-injured stimulation sites, and incorporation of individual characteristics is recommended. Insight into pathophysiological mechanisms underlying chronic post-burn itch could improve diagnostics and treatments.

Pruritus in the Pediatric Burn Population

Post-burn pruritus is a significant issue that can have a devastating impact on patient quality of life. Despite its known negative impact, few studies have focused on the pediatric population. Thus, the aim of this study was to determine the incidence of pruritus among pediatric burn patients as well as identify its predictive factors and commonly used treatments, including the novel use of laser therapy. A retrospective analysis of all burn patients treated at our pediatric burn centre from 2009 to 2017 was conducted. The primary outcome measure was the presence or absence of pruritus at any point following the burn. One thousand seven hundred and eighty-three patients met the inclusion criteria for this study. The mean age at injury was 3.67 years (SD 4.02) and the mean burn TBSA was 3.48% (SD 4.81) with most burns resulting from scalds (66%). In total, 665 patients (37.3%) experienced pruritus. Following multivariable logistic regression, TBSA, age > 5 years, burns secondary to fire/flames, and burn depth, were identified as significant predictors of pruritus (p < 0.05). Pruritus was treated with diphenhydramine (85.0%), hydroxyzine (37.3%), and gabapentin (4.2%) as well as massage (45.7%), pressure garments (20.0%), and laser therapy (8.6%). This study addresses the knowledge gap in literature related to post-burn pruritus among pediatric patients and includes one of the largest patient cohorts published to date. Moreover, the results further contribute to our understanding of post-burn pruritus in children and may help us to predict which patients are most likely to be affected, so that treatment can be initiated as soon as possible.

Silver Sulfadiazine Cream Treatment Results in More Wound Contraction and More Itch in a Standardized Porcine Scald Model

A variety of dressings is available for the treatment of partial-thickness wounds, but none has strong evidence supporting their beneficial effect on healing. This may be due to variation in the type and depth of wounds in clinical studies. The aim of this study was to use a standardized porcine wound model to compare three dressings commonly used in burn centers for partial-thickness burns. Partial-thickness scalds were made on the flanks of pigs. Wounds were treated with silver sulfadiazine (SSD, flammazine), a hydrofiber dressing, or glycerol-preserved allogeneic (pig) skin. The healing process was monitored for 8 weeks. Macroscopic parameters were the itching behavior, the cosmetic appearance of the scars, and contraction. Microscopic parameters were the inflammatory response, myofibroblast influx, and the numbers of nerves. All wounds were closed on day 14 and wound infection did not occur. Treatment with SSD resulted in significantly more wound contraction compared to treatment with glycerol-preserved pig skin. Animals treated with SSD suffered more from itching (scratching) during the first 2 weeks after wounding. The number of nerves in healing wounds of these animals was significantly higher compared to wounds treated with hydrofiber dressing or allogeneic skin. In our standardized porcine partial-thickness wound model, treatment with SSD resulted in less favorable wound healing. Compared to treatment with glycerol-preserved allogeneic skin, SSD resulted in more contraction.

Predictors and Correlates of Pediatric Postburn Pruritus in Preschool Children of Ages 0 to 4

Pruritus is a common problem following burn injuries; however, the literature to date has focused on adult survivors and/or pediatric survivors of large burns. The current study examines acute postburn pruritus in children under the age of 4 years (N = 256) with smaller burns (mean TBSA = 3.99%), which represents the most common type of patient typically treated in pediatric burn centers. Parents rated their child for pruritus, irritability, and sleep disturbances; additionally, parents completed a self-report of distress. Nearly half (47.3%) were rated by parents as displayed some level of pruritus, with the greatest proportion rated as mild. Regression analysis indicated that child minority status, greater burn TBSA, and more days elapsed since burn predicted higher levels of pruritus. In turn, pruritus was positively correlated with child irritability, delayed sleep onset, sleep disturbance, and parent distress. Thus, our results indicate that parent-rated pruritus in young pediatric burn patients is important to evaluate, as itch is significantly associated with other important clinical outcomes as early as the first month of the burn for pediatric patients and their parents.

Prevalence, pathophysiology and management of itch in epidermolysis bullosa

Epidermolysis bullosa (EB) is a highly diverse group of inherited skin disorders, resulting from mutations in genes encoding proteins of the dermoepidermal junction. Itch (pruritus) is one of the most common symptoms across all EB subtypes. It occurs in blistered or wounded sites, or manifests as a generalized phenomenon, thereby affecting both intact skin and healing wounds. The mechanism of pruritus in EB is unclear. It is likely that skin inflammation secondary to barrier disruption, wound healing cascades and dysregulated activation of epidermal sensory nerve endings are all involved in its pathophysiology on the molecular and cellular level. Understanding these mechanisms in depth is crucial in developing optimized treatments for people with EB and improving quality of life. This review summarizes current evidence on the prevalence, mechanisms and management of itch in EB.

Itching Caused by TRPV3 (Transient Receptor Potential Vanilloid-3) Activator Application to Skin of Burn Patients

Background and objectives: Postburn pruritus is a common complication of scars in burn patients. In our previous study, we discovered increased expression of TRPV3, TRPV4, and TRPA1. Among them, TRPV3, in particular, is predominantly expressed in the epidermis of the tissue of pruritic burn scars. We sought to evaluate the correlation between the expression of TRPV3 activators and itching after application of TRPV3 activator carvacrol over burn scars. Materials and Methods: Design: This was a double-blind clinical trial with non-randomized distribution.

SETTING

This study was performed in a hospital setting.

PATIENTS OR PARTICIPANTS

Patients with itching of burn scars (numerical rating scale (NRS), <3; n = 8; Group 1 and NRS, ≥3; n = 16, Group 2) and healthy volunteers (n = 18, Group 3) were included.

INTERVENTIONS

The investigational drug carvacrol (100%, 75%, and 50%) and control drug (10% ethanol) were applied over the scars using IQ Ultimate™ 1 × 1 cm chamber sheets.

MAIN VARIABLES OF INTEREST

The presence of pruritus, erythema, edema, and other skin lesions was evaluated. The verbal NRS scores were also compared. Results: Carvacrol induced more itching in Group 2 than in Groups 1 and 3. In Group 2, 100%, 75%, and 50% carvacrol caused significantly more itching (NRS score, 5.18 ± 3.04, 5.18 ± 3.04, and 4.93 ± 2.96, respectively) than that in Group 1 (NRS score, 1.00 ± 1.80, 1.00 ± 1.80, and 1.00 ± 1.80, respectively) and Group 3 (NRS score, 2.38 ± 1.94, 1.27 ± 1.32, respectively). Conclusions: The TRPV3 activator carvacrol can cause itching if applied over burn scars. This study can help understand the mechanism and prognosis of post-burn itching and contribute to the development of its treatment.

Post-Burn Pruritus

Post-burn pruritus is the pruritus that occurs after burn during the rehabilitation and healing process of burn wounds. The post-burn pruritus is a common and serious complication of burn injury, which severely lowers the quality of life of the patient. Many potential treatments are available for pruritus but there is no consensus of the best single treatment yet. The precise mechanism of post-burn pruritus has not been elucidated, but it appears to have pruritogenic and neuropathic aspects. Clinically, post-burn pruritus tends to be intractable to conventional treatment but rather responds to neuroleptic agents, such as gabapentin and pregabalin. During wound healing, various neuropeptides secreted from the nerves of the skin control epidermal and vascular proliferation and connective tissue cells. When keratinocytes are activated by an itch-inducing substance, they secrete a variety of inflammatory substances that increase the susceptibility of the itch receptor. There are two mechanisms underlying post-burn neuropathic pruritus. The first one is peripheral sensitization. The second one is the intact nociceptor hypothesis. An effective treatment for post-burn pruritus will also be effective in other neuropathic and intractable itching. In this review, we summarized the interaction and mechanism of keratinocytes, immune cells, and nerve fibers related to post-burn pruritus.

[Management of severe burn pain]

The experience of pain during a severe burn is multifactorial, both in the typology of the burn and in the circumstances of its occurrence. Third-degree burns are painless as the dermis and its nociception sensors are damaged. After a severe burn, from initial management, to home care, to a long hospital stay, pain evolves with its etiology and requires specific management.

Doxepin cream is not effective in reducing itch in burn scar patients: A multicenter triple-blind randomized clinical crossover trial

OBJECTIVE

To evaluate the effect of doxepin hydrochloride 5% cream on reducing pruritus in burn scar patients compared to a placebo cream.

METHOD

We conducted a multicenter triple-blind randomized clinical placebo-controlled crossover trial in which burn patients ≥18 years with an itch intensity ≥3 on a Visual Analogue Scale (VAS) were randomized between a doxepin-placebo or placebo-doxepin treatment protocol. Patients used each cream during two weeks with a wash-out period of one week in between. Primary outcome was change in itch intensity in two weeks' time using the VAS. Secondary outcome included the impact of itch (Burn Itch Questionnaire). Other parameters were the use of hydrating cream, silicon treatment, pressure garments, and other antipruritic medication.

RESULTS

Twenty-seven patients were included. The change in itch intensity (VAS) was not different during the doxepin and placebo period (p=0.994); neither the doxepin cream nor placebo cream reduced itch intensity. However, based on the Burn Itch Questionnaire, we observed a statistically significant decrease in itch intensity and improvement in impact scores in both treatment groups, but no difference in the degree of reduction between the groups.

CONCLUSION

Doxepin cream was not effective in reducing pruritus in our burn patient study population.

Patterns and predictors of burn scar outcome in the first 12 months after burn: The patient's perspective

OBJECTIVE

This study aimed to provide insight into the patterns and factors that predict burn scar outcomes at 3, 6 and 12 months after burn.

METHODS

The Patient and Observer Scar Assessment Scale (POSAS) was used to assess the scar formation of each patient. Structural equation modelling was used. The predictor variables used in this study were sex, three age categories, TBSA, depth of the wound and cause of the burn.

RESULTS

The POSAS patient total and individual item scores demonstrated a statistically significant decrease in the first 12 months after burn, except for the relief item. Male patients had a lower total and items scores (better scar quality) for pain and pruritus compared with female patients. Full thickness burns had a higher scores for pruritus, pliability, thickness and relief compared to the partial-thickness burns. Ages younger than 5 years, higher TBSA values and flame burns were predictors of various POSAS items at 3 and 6 months after burn.

CONCLUSION

The POSAS patient total and individual item scores demonstrated a statistically significant improvement in the scar quality in the first 12 months after burn, except for the relief. Sex, age, depth of the wound, the percentage of TBSA and flame burns were predictors of various POSAS patient items at 3, 6 and 12 months after burn.

The association of patient and burn characteristics with itching and pain severity

INTRODUCTION

Itch after burn injury causes significant distress to patients and can hamper functional recovery. Itching can persist on a time scale ranging from several weeks to even years after injury. In this study, we sought to determine predictors of itching after burn injury.

METHODS

We compared itch and pain severity among patients included in a burn registry at a level 1 trauma center. Both itch and pain severity was based on a 5-point scale. ANOVA, chi-squared, and multivariate analyses were performed to determine predictors of itch and pain severity.

RESULTS

Of the 1159 patients enrolled in the registry, 58% were male and 42% female, with a median age (IQR) of 27 (8-47) years. Most patients were diagnosed with 2nd degree superficial (41%) or deep (43%) burns. Upper extremities were the most common location of burn injury (59%), followed by lower extremities (31%), trunk (22%), and face/neck (20%). More than half (53%) of enrolled patients reported itching, ranging from minimal (19%) to severe (7%) itching. Multivariate analyses revealed age, sex (female), extent of burn injuries, and location (face/neck) to be predictors of itch after burn. Predictors of pain after burn were slightly different: age, extent of burn, and depth of burn.

CONCLUSION

Pain and itch after burn injuries are predicted by slightly different variables, presumably secondary to different underlying mechanisms. We conclude that age, sex (female), extent of burn injuries (total body surface area %), and injuries to the face/neck predict itching of greater severity. Patients with burn injuries that match these parameters would require greater care and closer follow up to reduce itching after healing.

Development of a Postburn Pruritus Relief Protocol

BACKGROUND

Postburn pruritus is a syndrome of stressful symptoms that is pervasive and occurs in over 90% of burn patients and continues for years after the burn has healed. Postburn pruritus is experienced by burn survivors that may require medical management and effective interventions.

PURPOSE

This article shows how to effectively relieve postburn pruritus by developing a postburn pruritus relief protocol.

DESIGN

A descriptive literature review was conducted, and relevant empirical articles written during the years 2000-2014 were appraised to create a postburn pruritus relief protocol. Twenty-six of 79 articles were selected using preestablished inclusion criteria: any age group experiencing burn-related pruritus after second- or third-degree burns. Databases were Cochrane Central Register of Controlled Trials, CINAHL, EBSCO, PubMed, the National Guideline Clearinghouse, Google Scholar, and the American Burn Association website.

CONCLUSIONS

This protocol included both nonpharmacological and pharmacological interventions that have been delineated for use and was developed to apply based on the healing stage: prehealing, healing, and posthealing.

Cultural adaptation of the 5-D itch scale and its reliability for Brazilian burn survivors

This was a methodological study whose objective was to culturally adapt the 5-D itch scale for Brazilian Portuguese and verify its practicability, acceptability and reliability for burn survivors. This study followed the five internationally recommended steps for the adaptation process: translation, synthesis, back translation, assessment by an expert committee and pretesting process; besides, an evaluation of its practicability, acceptability and reliability was conducted. The pretest was carried out with thirty burn survivors - hospitalized or on outpatient follow-up - from two public hospitals in the state of São Paulo. Most burn survivors were male (18; 60%), aged at mean of 39.2 (SD=11.1), with deep partial burn injuries (16; 59.3%), percentage of total burn surface area of 12.3 (SD=9.8); and most accidents occurred at domestic environment (18; 60%). The Brazilian version had semantic and idiomatic, conceptual and cultural equivalences, with a satisfactory content validity index for each item (CVI-I). Mean application time was 3.5minutes, acceptability was good, and there was evidence of reliability for the total score (0.793). The Brazilian version of the 5-D itch scale showed equivalence and evidence of reliability for assessing pruritus and its impact in burn survivors.

Post burn pruritus in pediatric burn patients

BACKGROUND

Pruritus is a common problem seen in the healing process of a burn wound and gives great discomfort for the patient. Most research in this field has been done in the adult population, so evidence in the pediatric population is still lacking PURPOSE: The aims of this study were to assess the incidence and severity of post-burn pruritus, identify predictors for pruritus and evaluate the pharmacological treatments in a pediatric setting.

METHODS

Pruritus was assessed in this prospective observational study using a numeric rating scale and the Itch Man Scale applied by the patients' caregiver. The predictive values of candidate predictors for pruritus were compared using Fisher exact tests and Kruskal-Wallis tests.

RESULTS

413 patients were included in this study. Pruritus was reported in 71.7% of the patients. Complete symptom relief was only achieved in 29.8% of the patients who used medication. Time since burn (p<0.001), depth of the injury (p=0.017), TBSA burned (p=0.001) and skin grafting (p=0.001) were found to be significant predictors for post-burn pruritus.

CONCLUSION

Post-burn pruritus is still a highly prevalent problem in pediatric burn care. Its intensity and frequency are higher especially in the first three months or with a deeper wound or a higher TBSA.

Nerve reinnervation and itch behavior in a rat burn wound model

In this study, we investigated whether postburn itch in rats, after a full thickness burn, is correlated to the nervous reinnervation of the burn wound area. For this purpose, we determined scratching duration (expressed as second/hour) at 24 hours, 2, 4, 8, and 12 weeks postburn and combined this with immunohistochemistry for protein gene product 9.5 (PGP9.5) to identify all nerve fibers, calcitonin gene related peptide (CGRP) to identify peptidergic fibers, tyrosine hydroxylase (TH) for sympathetic fibers, and growth-associated protein 43 (GAP-43) for regrowing fibers. We found a modest, but highly significant, increase in scratching duration of all burn wound rats from 3 to 12 weeks postburn (maximally 63 ± 9.5 second/hour compared to sham 3.1 ± 1.4 second/hour at 9 weeks). At 24 hours postburn, all nerve fibers had disappeared from the burn area. Around 4 weeks postburn PGP 9.5- and CGRP-immunoreactive nerve fibers returned to control levels. TH- and GAP-43-IR nerve fibers, which we found to be almost completely colocalized, did not regrow. No correlation was found between scratching duration and nervous reinnervation of the skin. The present results suggest that in rat, like in human, burn wound healing will induce increased scratching, which is not correlated to the appearance of nervous reinnervation.

Practice Gaps in Pruritus

There are several practice gaps in the evaluation and management of itch. These gaps include a dearth of objective measures of itch, infrequent use of validated patient-reported outcomes for itch, non-evidence-based treatment, and lack of consensus about the ideal workup for generalized itch. The present article reviews these gaps and presents potential solutions.

Management of a facial partial thickness chemical burn in a dog caused by bleach

OBJECTIVE

To describe the management and successful outcome of a late-recognition partial thickness bleach burn to the face and corneas of a dog.

CASE SUMMARY

A 1-year-old male neutered Fox Terrier mix breed dog was evaluated for sloughing facial epithelium 5 days after coming into contact with an 8.25% household bleach cleaning solution. Severe erythema, edema, and crusting were noted around the muzzle and margins of both eyes, with moderate to severe alopecia in these areas. A partially detached, partial thickness eschar was present on the muzzle, while a firmly attached eschar was present in the region of both frontal sinuses. These injuries were consistent with a focal, superficial, and partial thickness chemical burn. Multiple ocular abnormalities, the most concerning of which was corneal ulceration, were also present. The patient's wounds were managed conservatively with limited surgical debridement of the affected epithelium 11 and 22 days after the initial exposure. Topical ocular medications, corneal debridement, and a superficial keratectomy were also used. All lesions resolved completely by 84 days postexposure, with no residual effects on the patient's quality of life.

NEW INFORMATION

Chemical burns caused by contact with alkaline agents such as bleach (sodium hypochlorite) result in extensive necrosis of the skin and underlying structures. This is the first report of management alkaline facial burns in a dog. If inadequate or delayed hydrotherapy following exposure has resulted in superficial partial thickness burns, conservative management can be successful when traditional treatments, especially bandaging, are not feasible.

Increased activity of TRPV3 in keratinocytes in hypertrophic burn scars with postburn pruritus

Postburn pruritus is a common distressing sequela of burn wounds. Empirical antipruritic treatment often fails to have a satisfactory outcome, as the mechanism of it has not been fully elucidated. The aim of this study was to evaluate the manifestation of transient receptor potential vanilloid 3 (TRPV3), transient receptor potential ankyrin 1 (TRPA1), and other related receptors in postburn pruritus. Sixty-five burn patients with (n = 40) or without (n = 25) pruritus were investigated, including skin biopsies. Keratinocytes and fibroblasts from skin biopsy samples were separated. Real time-PCR showed that mRNA of TRPV3 was significantly increased in keratinocytes from pruritic burn scars than in keratinocytes from nonpruritic burn scars. With TRPV3 activation, intracellular Ca²⁺ concentrations were more significantly increased in keratinocytes from pruritic burn scars than in those from nonpruritic ones. Additionally, mRNA and protein levels of protease-activated receptor 2 (PAR2) and neurokinin-1 receptor (NK1R) were also significantly increased in pruritic burn scars. In conclusion, it was confirmed that TRPV3, PAR2, and NK1R were highly expressed in pruritic burn scars. These results may help determine a novel mechanism for postburn pruritus.

Prevalence and prediction of prolonged pruritus after severe burns

Years after injury, pruritus is a common and severe problem for many burn patients. However, its characteristics and consequences are often only partially described. The authors therefore performed a prospective detailed examination of burn- and individual-related factors and considered those in relation to pruritus severity. Sixty-seven consecutive burn patients were assessed during acute care, and at 3 and 12 months postburn regarding preburn psychiatric disorders, health-related quality of life, post traumatic stress disorder, and personality traits. Postburn pruritus was subsequently assessed 2 to 7 years postburn using the Questionnaire for Pruritus Assessment. Fifty-one individuals, 76% of the participants, reported burn pruritus any time after the burn. Thirty-three individuals, 49% of the participants, reported ongoing pruritus the last 2 months. Information on the characteristics of pruritus was obtained from 32 of these individuals. Most perceived pruritus as bothersome or annoying and as present every day, 16 (50%) were considered to have severe pruritus, and 11 (34 %) scratched themselves to the point of bleeding. In logistic regressions, this was independently related to TBSA full-thickness burn and health-related quality of life at 3 months, and to TBSA full thickness burn and the personality trait impulsiveness, respectively. About half of the previous burn patients experienced ongoing pruritus on an average of 4.5 years after injury, and half of them had severe pruritus. Scratching oneself to the point of bleeding is linked both to a certain personality and to pruritus. It is suspected that many patients are left without access to the best available treatment.

Recovery trajectories after burn injury in young adults: does burn size matter?

The impact of burn size on mortality is well known, but the association of burn size with the trajectories of long-term functional outcomes remains poorly studied. This prospective multi-center study included burned adults ages 19 to 30 years who completed the Young Adult Burn Outcome Questionnaire at initial baseline contact, 2 weeks, and at 6 and 12 months after initial questionnaire administration. Non-burned adults of comparable ages also completed the questionnaire as a reference group. The association between functional recovery and TBSA burned was analyzed longitudinally using generalized linear models with the generalized estimation equation technique. Functional status was characterized in 15 domains: physical function, fine motor function, pain, itch, social function limited by physical function, perceived appearance, social function limited by appearance, sexual function, emotion, family function, family concern, satisfaction with symptom relief, satisfaction with role, work reintegration, and religion. Scores were standardized to a mean of 50 and a SD of 10 based on non-burned controls. There were 153 burned and 112 non-burned subjects with a total of 620 questionnaires. TBSA burned was 11 ± 14% (mean ± SD); 31% had face involvement and 57% had hand involvement. The lag time from burn injury to questionnaire administration was on average 7 ± 7.7 months, with a maximum of 36 months. Lower recovery levels were associated with increasing burn size for physical function, pain, itch, work reintegration, emotion, satisfaction with symptom relief, satisfaction with role, family function, and family concern (P value ranged from .04-<.0001). No significant differences in recovery levels were found with increasing burn size for fine motor function, social function limited by physical function, sexual function, and religion; these areas tracked toward the age-matched non-burned group regardless of burn size. Perceived appearance and social function limited by appearance remained below the non-burn levels throughout the 3-year period regardless of burn size. Three-year recovery trajectories of survivors with larger burn size showed improvements in most areas, but these improvements lagged behind those with smaller burns. Poor perceived appearance was persistent and prevalent regardless of burn size and was found to limit social function in these young adult burn survivors. Expectations for multidimensional recovery from burns in young adults can be benchmarked based on burn size with important implications for patient monitoring and intervening in clinical care.

Race and Melanocortin 1 Receptor Polymorphism R163Q Are Associated with Post-Burn Hypertrophic Scarring: A Prospective Cohort Study

The genetic determinants of post-burn hypertrophic scarring (HTS) are unknown, and melanocortin 1 receptor (MC1R) loss-of-function leads to fibrogenesis in experimental models. To examine the associations between self-identified race and MC1R single- nucleotide polymorphisms (SNPs) with severity of post-burn HTS, we conducted a prospective cohort study of burned adults admitted to our institution over 7 years. Subjects were evaluated using the Vancouver Scar Scale (VSS), asked to rate their itching, and genotyped for 8 MC1R SNPs. Testing for association with severe HTS (VSS>7) and itch severity (0-10) was based on multivariate regression with adjustment for known risk factors. Of 425 subjects analyzed, 77% identified as White. The prevalence of severe HTS (VSS>7) was 49%, and the mean itch score was 3.9. In multivariate analysis, Asian (prevalence ratio [PR] 1.54; 95% CI: 1.13-2.10), Black/African American (PR 1.86; 95% CI: 1.42-2.45), and Native American (PR 1.87; 95% CI: 1.48-2.35) race were independently associated with severe HTS. MC1R SNP R163Q was also significantly (P<0.001) associated with severe HTS. Asian race (linear regression coefficient 1.32; 95% CI: 0.23-2.40) but not MC1R SNP genotype was associated with increased itch score. We conclude that MC1R genotype may influence post-burn scarring.

Physical and psychiatric recovery from burns

Burn injuries pose complex biopsychosocial challenges to recovery and improved comprehensive care. The physical and emotional sequelae of burns differ, depending on burn severity, individual resilience, and stage of development when they occur. Most burn survivors are resilient and recover, whereas some are more vulnerable and have complicated outcomes. Physical rehabilitation is affected by orthopedic, neurologic, and metabolic complications and disabilities. Psychiatric recovery is affected by pain, mental disorders, substance abuse, and burn stigmatization. Individual resilience, social supports, and educational or occupational achievements affect outcomes.

Prevalence and characterization of pruritus in epidermolysis bullosa

Qualitative data suggest that pruritus is a burdensome symptom in patients with epidermolysis bullosa (EB), but the prevalence of pruritus in children and adults with EB and factors that contribute to pruritus are unknown. The objective of the current study was to quantitatively identify and to characterize pruritus that EB patients experience using a comprehensive online questionnaire. A questionnaire was developed to evaluate pruritus in all ages and all types of EB. Questions that characterize pruritus were included and factors that aggravate symptoms were investigated. Patients from seven North American EB centers were invited to participate. One hundred forty-six of 216 questionnaires were completed (response rate 68%; 73 male, 73 female; median age 20.0 years). Using a 5-point Likert scale (1 = never, 2 = rarely, 3 = sometimes, 4 = often, 5 = always), itchiness was the most bothersome EB complication (mean 3.3). The average daily frequency of pruritus increased with self-reported EB severity. Pruritus was most frequent at bedtime (mean 3.8) and interfered with sleep. Factors that aggravated pruritus included healing wounds, dry skin, infected wounds, stress, heat, dryness, and humidity. Pruritus is common in individuals with EB and can be bothersome. Future studies will need to investigate the most effective treatments given to individuals with EB for pruritus.

Physical and psychiatric recovery from burns

Burn injuries pose complex biopsychosocial challenges to recovery and improved comprehensive care. The physical and emotional sequelae of burns differ, depending on burn severity, individual resilience, and stage of development when they occur. Most burn survivors are resilient and recover, whereas some are more vulnerable and have complicated outcomes. Physical rehabilitation is affected by orthopedic, neurologic, and metabolic complications and disabilities. Psychiatric recovery is affected by pain, mental disorders, substance abuse, and burn stigmatization. Individual resilience, social supports, and educational or occupational achievements affect outcomes.

Psychological management of wound pruritus

OBJECTIVE

To explore the psychological treatment options for pruritus in patients with wounds.

METHOD

This study employed a narrative design with a search being completed using the databases Academic Search Complete, Google Scholar, PsycInfo, PsycARTICLES, Medline and CINAHL Plus. All articles between 1980-2013 that included the following search terms: [pruritus OR itch OR itching] AND [management OR psychological interventions OR treatment] AND [wounds OR burns OR wounds burns] were included in the review.

RESULTS

A number of psychological treatments options emerged from the literature search that were suggested to be effective for treating itching. These included methods such as habit reversal, suggestions, relaxation, massage and itch-coping programmes. Each of these methods showed potential for improving the patient experience by reducing itching, although the research evidence is currently somewhat limited.

CONCLUSION

Although itching is a common symptom in wounds, the use of psychological treatments for this may be rather limited. The treatments discussed show promise and their use should be a welcome addition to the healthcare professional's armoury for working with people with wounds.

DECLARATION OF INTEREST

There were no external sources of funding for this study. The authors have no conflicts of interest to declare.

Intra-epidermal nerve fibres in human skin: back to the roots

Regarding the existence and the role of intra-epidermal nerve fibres, the literature is ambiguous. However, performing a literature search, a landmark paper turned up that even many dermatologists seem to have forgotten, or may not even know at all. This paper is entitled 'The innervation of human epidermis' written by Arthur and Shelley (J Invest Dermatol, 32, 1959, 397). The full text is available via http://www.nature.com/jid/journal/v32/n3/pdf/jid195969a.pdf. The authors present data on intra-epidermal nerves at 16 representative body areas. The existence of intra-epidermal nerve fibres is undisputable and does not only explain clinical symptoms but may even provide a promising target for drug development.

Accidental PUVA burns, vitiligo and atopic diathesis resulting in prurigo nodularis: a logical but undocumented rarity

Vitiligo is a dreaded disease in India due to its social and cultural consequences. PUVA and PUVAsol are the main treatment modalities for vitiligo vulgaris. To the best of our knowledge, this is the first case of accidental PUVA burns eventuating in prurigo nodularis lesions to be reported in a female patient who was undergoing home PUVA therapy. The itch is so prominent and disabling that the focus of the patient has shifted from treating her vitiligo to ameliorating the pruritus.

Pruritus in adult burn survivors: postburn prevalence and risk factors associated with increased intensity

Pruritus (itching) is a common and distressing complaint after injury. The purpose of this study was to investigate self-reported postburn pruritus in a large, multisite cohort study of adult burn survivors. Descriptive statistics, general linear regression, and mixed model repeated measures analyses were employed to test statistical significance. Two cohorts of adult burn survivors were studied. Group 1 participants (n = 637) were injured from 2006 to 2010 and were followed up prospectively for 2 years from the time of injury. Prevalence and severity of pruritus were compared across multiple subgroups. Prevalence of pruritus at discharge, 6, 12, and 24 months following injury were 93, 86, 83, and 73%, respectively. Regression results established that %TBSA-burn and %TBSA-grafted were correlated to itch intensity values. Group 2 participants (n = 336) were injured 4 to 10 years before an assessment using the validated 5-D Itch Scale. Many patients (44.4%) reported itching in the area of the burn, graft, or donor site. Within this group, 76% reported itching for <6 hours/day, and 52 and 29% considered itch intensity to be mild or moderate, respectively. This study confirms that the prevalence of burn pruritus is high, initially affecting >90% and persisting for >40% of long-term burn survivors. New predictors for postburn itch were identified to include younger age, dry skin, and raised/thick scars. Characterization of the impact of postburn pruritus on leisure, vocation, and sleep are quantified for those long-term survivors suffering from postburn pruritus.

Neuropathic mechanisms in the pathophysiology of burns pruritus: redefining directions for therapy and research

Pruritus in burn wounds is a common symptom affecting patient rehabilitation. Over the last decades, there has been a resurgence of interest into more effective strategies to combat this distressing problem; nevertheless, no reports exist in the literature to propose pathophysiological mechanisms responsible for the generation and persistence of pruritic symptoms in the late phases of burns rehabilitation. Neuronal pathways mediating pruritic and painful stimuli share striking similarities, which allows the comparative exploration of the less extensively studied pruritic mechanisms using pain models. Furthermore, emerging anatomical, neurophysiological, and pharmacological evidence supports the involvement of neuropathic mechanisms in chronic burns pruritus. This work updates the conceptual framework for the pathophysiology of burns itch by embracing the contribution of the central nervous system in the maintenance of symptoms into a chronic state. The proposed pathophysiological model paves new avenues in burns pruritus research and is likely to have implications in the quest for more effective therapeutic regimens in clinical practice.

Intrahepatic cholestasis of pregnancy: new insights into its pathogenesis

AIM

To search a specific gene expression profile in women with intrahepatic cholestasis of pregnancy (ICP) and to evaluate the maternal and foetal outcome.

METHODS

We consecutively enrolled 12 women with ICP and 12 healthy pregnant controls. The gene expression profile was assayed with the microarray technique including a panel of 5541 human genes. Microarray data were validated by real-time PCR technique.

RESULTS

Caesarean delivery was performed in eight patients with ICP versus three controls (p = 0.05). ICP women delivered at earlier gestational age than control (p < 0.001). Foetal distress was recorded in two babies, but we failed to find any correlation between bile salt concentration and foetal distress. Twenty genes potentially correlated with ICP were found differentially expressed (p < 0.05). Among these, three belong to genetic classes involved in pathogenic mechanisms of ICP: (1) pathophysiology of pruritus (GABRA2, cases versus controls = 2, upregulated gene); (2) lipid metabolism and bile composition (HLPT, cases versus controls = 0.6, down-regulated gene) and (3) protein trafficking and cytoskeleton arrangement (KIFC3, cases versus controls = 0.5, down-regulated gene).

CONCLUSIONS

Different gene expression may contribute to the complex pathogenesis of ICP. An upregulation of GABRA2 receptor may indicate that GABA may play a role in the pathogenesis of pruritus in this condition.

Spanish transcultural adaptation of the Leuven Itch Scale

Itching is one of the most frequent symptoms, and most resistant to treatment, relating to scar formation after burns. The Leuven Itch Scale is a questionnaire which has been validated for use in burns, analysing different clinical dimensions of pruritus. However, until now there was no Spanish version available for use with Spanish-speaking patients. This article presents the process of the academic translation of the questionnaire in order to obtain a Spanish version, and the final version of the questionnaire. We followed a translation/back-translation methodology with a final pilot test on a sample of burn patients. The final result fills a major gap in the quality-of-life questionnaires available in Spanish.

A four arm, double blind, randomized and placebo controlled study of pregabalin in the management of post-burn pruritus

Post-burn itch is a distressing symptom in burns rehabilitation and its treatment often proves frustrating for the patient and the multidisciplinary burns team. Traditionally, the mainstay of antipruritic therapy for decades has been antihistamines and massage with emollients. With a better understanding of the neurophysiology of itch emerged a new dimension in the treatment of post-burn pruritus. Gabapentin, a centrally modulating anti-epileptic agent and α2δ ligand, proved in clinical trials to be immensely better in the treatment of post-burn pruritus. Pregabalin is a newer structural analog of gabapentin. It has a much better anxiolytic effect and pharmacokinetic profile as compared to gabapentin. The current study was initiated to specifically study the role of pregabalin in relieving post-burn itch as this has never been investigated before. This double blind, randomized and placebo controlled study had four arms and was carried out on 80 adult patients (20 each). The four arms were: pregabalin, cetirizine with pheniramine maleate, combination of pregabalin, cetirizine and pheniramine maleate, and placebo (vit. B comp.). Massage with coconut oil was integral to all groups. Drug dosage was determined by initial VAS (visual analog scale) scores. All groups matched in demographic data and initial VAS scores. VAS scores were evaluated over next 28 days (days 3, 7, 14, 21 and 28). In patients with mild itch (VAS scores 2-5) or moderate itch (VAS scores 6-8) near complete remission of itch was seen in combination group and pregabalin group where the response was comparable and close to 95%. This was significantly better response than antihistaminic combination or massage alone. However, massage alone was sufficient in decreasing mean scores in mild itch, in a large percentage of patients. Amongst the patients with severe itch (VAS scores 9-10), 3/6 and 6/7 patients dropped out of trial in the antihistaminic and placebo groups, respectively. Combination therapy and pregabalin alone had exactly similar decrease in itch scores by day 28 (78.9%). This far exceeded the response in the antihistaminic and placebo groups (23.9% and 9.2% respectively). We conclude that moderate to severe pruritus (VAS 6-10) should be treated with a systemic, centrally acting agent like pregabalin or gabapentin to eliminate itch or bring it down to tolerable limits. Patients with mild itch having VAS scores between 4 and 5 may be better served with addition of pregabalin even if massage and antihistaminics can control post-burn itch to a reasonable extent because of quicker, predictable and complete response, along with anxiolysis.

Assessment of pruritus characteristics and impact on burn survivors

The goal of this cross-sectional study was to characterize and describe persistent postburn pruritus. Cause and treatment of postburn itch is elusive. It has been suggested that burn survivors with persistent pruritus should be divided into acute itch (≤6 months postinjury) and chronic itch (>6 months postinjury) because the cause of itch may be different. Cross-sectional data of itch characteristics reported here are from the baseline data of a prospective, randomized, double-blind, controlled pilot study of 23 subjects with frequent and bothersome postburn pruritus. Subjects self-completed validated scales for variables of itch sensation, affect of itch, and severity. Variables of quality of life, frequency, pain and itch intensity, skin condition, scar, and medication were also recorded. Itch frequency revealed that 87% of subjects experienced itching daily, 96% experienced three or more episodes a day, and 52% had episode durations lasting 5 to 30 minutes per incidence. Itch was reported as unbearable by 94% of subjects with chronic itch and by 86% of subjects with acute itch, whereas bothersome was 88 and 100%, respectively. Itch sensation dimension of stinging was 74% in both acute and chronic itch subjects. Crawling and burning sensations were often severe. Potential itch triggers and relief activities were identified. Differences in sensory and affective itch components were detected between acute and chronic itch subjects. Combinations of itch mechanisms probably contribute to the development of and changes in pruritus. Characterizing the sensation and affective itch dimensions in conjunction with inflammation, burn injury, recovery, scar maturation, medication, and psychological status should better elucidate postburn itch.