Autonomous healing of fatigue cracks via cold welding.

Fatigue in metals involves gradual failure through incremental propagation of cracks under repetitive mechanical load. In structural applications, fatigue accounts for up to 90% of in-service failure1,2. Prevention of fatigue relies on implementation of large safety factors and inefficient overdesign3. In traditional metallurgical design for fatigue resistance, microstructures are developed to either arrest or slow the progression of cracks. Crack growth is assumed to be irreversible. By contrast, in other material classes, there is a compelling alternative based on latent healing mechanisms and damage reversal4-9. Here, we report that fatigue cracks in pure metals can undergo intrinsic self-healing. We directly observe the early progression of nanoscale fatigue cracks, and as expected, the cracks advance, deflect and arrest at local microstructural barriers. However, unexpectedly, cracks were also observed to heal by a process that can be described as crack flank cold welding induced by a combination of local stress state and grain boundary migration. The premise that fatigue cracks can autonomously heal in metals through local interaction with microstructural features challenges the most fundamental theories on how engineers design and evaluate fatigue life in structural materials. We discuss the implications for fatigue in a variety of service environments.

Male genital lichen planus: A retrospective study of 89 cases.

BACKGROUND: Unlike other types of lichen planus (LP), there are no series concerning male genital LP. OBJECTIVE: To describe the clinical characteristics, diagnosis, and response to treatment of male genital LP. PATIENTS AND METHODS: A retrospective study of male patients with genital LP consulting a dermatologist specialized in anogenital diseases between January 2010 and 2019. Demographic data, history, functional signs, clinical characteristics, pathology, complications, and treatment efficacy were collected. RESULTS: Eighty-nine patients were included at four centers. The median age was 51 years. Most patients were uncircumcised and asymptomatic. In 88.8% of cases, only the genital mucosa was involved. Erythema (71%), papules (21.3%), lacy network (15.7%), atrophic lesions (15.7%), erosions (14.6%), and post-inflammatory hyperpigmentation (2.2%) were less frequently observed. Biopsy results confirmed LP in 61.3% of cases but could not rule out other inflammatory genital dermatoses in other cases. Anatomic complications were observed in 30.3% of patients. Topical corticosteroids (TCS) induced remission in most cases. Tacrolimus efficacy was comparable to that of TCS. CONCLUSION: Male genital LP is a rare inflammatory disorder chiefly affecting uncircumcised men. It is found predominantly on the mucosal component of the penis and presents as non-erosive inflammatory balanitis in most cases, with frequent partial or complete remission on treatment with TCS.

Impact of systemic to topical steroids switch on the outcome of drug reaction with eosinophilia and systemic symptoms (DRESS): A monocenter retrospective study of 20 cases.

BACKGROUND: There is no consensus on the treatment of drug reaction with eosinophilia and systemic symptoms (DRESS). At our center, systemic steroids (SS) are used for severe cases while topical steroids (TS) are used for mild and moderate forms. OBJECTIVES: To investigate the short-term outcome for patients with DRESS receiving SS as first-line therapy before being transferred to our department and then switched to TS after admission. METHODS: A retrospective monocenter study in DRESS patients (RegiSCAR score≥4) transferred to our dermatology department from a different setting between 07/2012 and 06/2018 and who had received SS before being transferred. Epidemiological, clinical and laboratory data were collected, as well as details of treatment modalities and outcome. RESULTS: Twenty patients were included. On admission to our department, 4 were assessed as having severe DRESS and continued on SS, while 16 were assessed as mild/moderate DRESS and were switched to TS. Among these 16 patients, the outcome on TS was favorable for 12 and quickly unfavorable for 4, who had to be switched back to SS. Retrospective analysis of the initial data (before transfer) showed that these 4 patients had previously had a greater number of severity criteria than the other 12. CONCLUSION: Caution is needed not only when deciding to initiate SS in DRESS but also on withdrawal of these drugs. Our series suggests that when SS are used as first-line therapy in DRESS patients with initial severity criteria, they should not be withdrawn quickly for a switch to TS, even where progression appears favorable, due to the risk of relapse.

[Human poxvirus infections]. / Infections humaines à poxvirus.

Poxvirus (PXV) infections are a common cause of cutaneous signs. In France, certain forms of poxvirus are frequent and benign (molluscum contagiosum), while others are rare but potentially serious (cowpox virus [CPXV]). Whereas only smallpox and molluscum contagiosum viruses have a human reservoir and are transmitted between humans, most poxvirus infections are zoonoses having only animal reservoirs. Only a small number of poxviruses are responsible for infection in humans, but the increasing number of new pets, some of which are exotic, coupled with the rapid rise in international travel are creating a greater risk of transmission of zoonotic PXV to new vectors and of spread of these diseases to new regions throughout the world. In France, molluscum contagiosum, orf and milkers' nodule give rise to numerous consultations and are well known to dermatologists. However, dermatologists must also be able to identify other parapoxviruses of similar presentation to orf; thus, CPXV and monkeypox are considered potentially emergent viruses with a high risk of epidemic and spread due to increasing international transport and the loss of the maximum protection against smallpox. Finally, despite its declared eradication, smallpox is currently being monitored because of the potential risk of reintroduction, whether accidentally or deliberately through bioterrorism.

Wearing of examination gloves and hygiene practice among dermatologists: A national survey.

INTRODUCTION: Touch is essential for dermatologists. Differences in practice, such as whether or not to wear examination gloves, may be seen among dermatologists. To investigate this approach and its associated factors, we conducted a national survey to study hygiene measures and the wearing of gloves among dermatologists, e.g. wearing a coat, hand washing between patient visits, hand shaking and past history of infectious disease transmitted by patients. The context and circumstances in which gloves were worn was studied. RESULTS: Four hundred and seventy-four dermatologists responded to the survey (median age: 52 years). Most dermatologists reported wearing examination gloves as follows: always (21%, n=99), occasionally (76%, n=359), never (3%, n=13). Most physicians reported wearing a coat (91%, n=419) and routinely washing their hands after examination (53%, n=241). A minority of physicians reported shaking hands (36%, n=163). A significant number of dermatologists reporting that they wore examination gloves were younger and female, and these practitioners also washed their hands more frequently. The most common reason cited by dermatologists wearing gloves "occasionally" was patient hygiene (71%, n=256) rather than infectious skin disease (52%, n=186). This practice was ascribable more to concerns by dermatologists about protecting themselves (78%, n=270) rather than protecting patients (51%, n=169). Finally, it was felt that wearing gloves impaired neither the quality of clinical examination (52%, n=173) nor relations with patients (49%, n=160). CONCLUSION: Although wearing gloves is not recommended for examining unbroken skin, most of the respondents reported wearing examination gloves during their consultations. Wearing of gloves was associated with more frequent hygiene measures (hand washing, no handshaking) and was based on concern for self-protection.

Dermatological emergencies: evolution from 2008 to 2014 and perspectives.

BACKGROUND: Our dermatological department includes a dermatological emergency unit (DEU) whose activity has grown in recent years. OBJECTIVES: An audit to characterize the activity of our DEU and its evolution in terms of medical demographics of the area. METHODS: We collected the following data from administrative services: number of patients consulting each year in the DEU and in the general emergency unit (GEU) of our hospital between 2008 and 2014; daily and seasonal activity of the DEU; occurrence of a second event in the department and proportion of patients from the DEU who were hospitalized and why. From the medical charts of a random sample of patients consulting in the first 15 days of January and August 2014, we studied the epidemiological profile, time to consultation and diagnoses. Data related to medical demographics (number of general practitioners and dermatologists) between 2007 and 2014 and projections were obtained. RESULTS: The activity in the DEU increased by 67% between 2008 and 2014 but remained stable in the GEU over the same period. The activity was higher on Mondays and in the summer (+30%). More than 15% of the patients were seen a second time in outpatient consultation; 1.2% were hospitalized. Infectious dermatosis was the main reason for consultation; seasonal-disease consultations were more frequent in the summer. Less than 40% of patients consulted in the first week after disease onset. Medical demographics continually decreased since 2007 in Paris and suburbs and will continue to decrease in the next years. CONCLUSION: The increasing activity of our DEU parallels the decrease in medical demographics in Paris. The proportion of patients hospitalized was low, in part due to specific healthcare networks implemented for some life-threatening dermatoses independent of the DEU. A better coordination between hospital and private practitioners for managing dermatologic emergencies, taking into account the decrease in medical demographics, is warranted.

Histopathology of drug rash with eosinophilia and systemic symptoms syndrome: a morphological and phenotypical study.

BACKGROUND: The histopathological features of drug rash with eosinophilia and systemic symptoms (DRESS) syndrome remain poorly characterized. OBJECTIVES: To better characterize the histopathological features of DRESS syndrome, and define the phenotype of the effector cells in the skin and compare it with maculopapular rash (MPR). METHODS: We conducted a retrospective study on 50 skin biopsies from patients with DRESS syndrome (n = 36). Histopathological and immunophenotypical features were studied and compared with a series of MPRs (n = 20). RESULTS: Foci of interface dermatitis, involving cutaneous adnexae, were frequently seen in cases of DRESS. Eosinophils were seen in only 20% of cases and neutrophils in 42%. Eczematous (40%), interface dermatitis (74%), acute generalized exanthematic pustulosis-like (20%) and erythema multiforme-like (24%) patterns were observed. The association of two or three of these patterns in a single biopsy was significantly more frequent in cases of DRESS than in a series of nondrug-induced dermatoses (P < 0.01), and appeared to be more marked in DRESS syndrome with severe cutaneous lesions (P = 0.01) than in less severe cases of DRESS and MPR. A higher proportion of CD8(+) and granzyme B(+) lymphocytes was observed in cases of DRESS with severe cutaneous eruptions (erythroderma and/or bullae). Atypical lymphocytes were found in 28% of biopsies, and expressed CD8 in most cases; a cutaneous T-cell clone was rarely found (6%). CONCLUSIONS: The histopathology of DRESS syndrome highlights various associated inflammatory patterns in a single biopsy. Cutaneous effector lymphocytes comprise a high proportion of polyclonal CD8(+) granzyme B(+) T lymphocytes.

Dermatological emergencies: a comparative study of activity in 2000 and 2010.

BACKGROUND AND OBJECTIVE: Studies of dermatological emergencies (DE) are few. We evaluated the activity in our DE unit in a 1-month retrospective study and compared the results with a similar study performed in the same department in 2000. METHODS: We reviewed the charts of all outpatients seen in the DE unit in January 2010, collecting data on age, sex, place of residence, referral mode, day and hour of consultation, true emergency or non-emergency, diagnosis and follow-up. RESULTS: In January 2010, we serviced 605 patients (58% males, mean age 40 ± 21 years), 21% more than in 2000; 43.5% were seen during off-duty hours vs. 49% in 2000 (P = 0.066), 49% were considered true emergencies vs. 43% in 2000 (P = 0.046), and 14% were referred by a physician vs. 23% in 2000 (P = 0.0001). In total, 35.2% of cases were infectious dermatoses in 2010 vs. 29% in 2000 (P = 0.026). Other diagnoses were eczema, urticaria and drug-related eruptions. Follow-up was suggested to 53.3% of the patients. CONCLUSIONS: Our DE unit satisfies a genuine need. Its activity increased over 10 years, most likely because of the decrease in the number of dermatologists in France. Although our results are close to those reported in the literature, comparison with previously published studies is difficult because of the heterogeneity of the definition of DE.

[Subacute cutaneous lupus erythematosus and cancer: two cases and literature review]. / Lupus cutané subaigu et cancer: deux cas et revue de la littérature.

BACKGROUND: Subacute cutaneous lupus erythematosus is an uncommon dermatosis characterised by a non-scarring, annular photo-distributed dermatosis associated with anti-Ro/SSA antibodies. It is remarkable as a paraneoplastic syndrome (12 cases in the literature). We report two cases of subacute cutaneous lupus erythematosus occurring in patients treated for metastatic breast adenocarcinoma. CASE REPORTS: Case 1: a 72-year-old woman with breast carcinoma relapsing after surgery, chemotherapy, hormone therapy, and without treatment for 6 months, was admitted for an acute erythematous slightly squamous and photo-distributed eruption. On clinical examination, she was found to be presenting polyadenopathy and pleural effusion. Case 2: a 46-year-old woman with a history of breast carcinoma was admitted for an erythematopapular, annular and photo-distributed eruption occurring after a second breast cancer relapse and five months after initiation of docetaxel. A new line of chemotherapy initially resulted in regression of the lesions, and progression of the breast cancer was associated with cutaneous relapse. DISCUSSION: The diagnosis of subacute cutaneous lupus erythematosus was supported in our two patients by the presence of an annular photo-distributed eruption associated with positive testing for anti-Ro/SSA antibodies. Occurrence of the eruption in both cases with relapse of the neoplasia and its improvement after oncological treatment reinforced the diagnosis of paraneoplastic syndrome in one case, and the use of chemotherapy known to trigger lupus could have suggested a diagnosis of drug-induced subacute cutaneous lupus erythematosus. Thus, the association between lupus and cancer is relevant.

[Measles in adults: an emerging disease not sparing medical staff]. / Rougeole de l'adulte : une maladie émergente n'épargnant pas le personnel médical.

BACKGROUND: A large outbreak of measles is taking place in Europe and is related to a low vaccination coverage. Measles is observed in adults. METHODS: We retrospectively studied all the consecutive cases of measles seen in adults between the 1/1/2007 and the 30/4/2009 in four Parisian hospitals. RESULTS: Twenty-one patients were included. Six patients (29%) were health care workers (HCW) including five (83%) who were vaccinated. Twenty (95%) patients were hospitalized. All patients presented with febrile exanthema, cough and rhinitis in association with hepatic involvement in 71%. Neither death nor sequelae were reported. CONCLUSION: Measles may occur in HCW, most of them being insufficiently covered by the vaccination. Therefore, since 2010, one injection of measles vaccine is now recommended in France, for HCW without history of measles or vaccination with two doses. Furthermore, adequate respiratory precautions should be taken when seeing patients with febrile exanthema and cough.

The effect of subcutaneous injection of methylprednisolone acetate and lidocaine for refractory postherpetic neuralgia: a prospective, observational study.

BACKGROUND: Postherpetic neuralgia (PHN) is the most common and bearable complication of herpes zoster (HZ). This pain may have negative impact on the patient's all aspects of daily life and health-related quality of life (HRQOL). Despite numerous advances in treatment, many patients remain resistant to the current therapy options. It is the first time subcutaneous injection of methylprednisolone acetate and lidocaine has been used to treat refractory PHN. We report the results of this treatment evaluating pain relief and HRQOL improvement in this disorder. METHODS: A total of 43 patients with refractory PHN was enrolled in the observational study. All patients received daily subcutaneous injection of methylprednisolone acetate and lidocaine for 10 consecutive days. The severity of pain was assessed by using Visual Analog Scale (VAS), and 36-Item Short Form Survey (SF-36) was applied to evaluate HRQOL. Assessment of the pain and HRQOL was carried out at baseline and posttreatment at 4 weeks as well as 6 and 12 months. RESULTS: At baseline, all patients experienced severe PHN with average VAS scores of 8.44 ± 0.85 (minimum 7; maximum 10). At 4 weeks, 6 months, and 12 months after treatment, the pain had significantly decreased (P < .001), and all subjects showed significant improvement in all eight domains of HRQOL. No major adverse events associated with the subcutaneous injection were observed. CONCLUSIONS: Our results indicate that subcutaneous injection of methylprednisolone acetate and lidocaine can be an effective and safe treatment for PHN.

[Cutaneous infections in bullous pemphigoid patients treated with topical corticosteroids]. / Infections cutanées chez les patients atteints de pemphigoïde bulleuse traités par dermocorticoïdes.

BACKGROUND: Potent topical corticosteroids (TCS), such as clobetasol propionate are more efficacious than systemic corticosteroids in the treatment of bullous pemphigoid (BP) and in reducing the rate of systemic infectious complications. However, TCS can have cutaneous side effects, such as atrophy and purpura. The risk of cutaneous infections due to TCS in BP is known but has never been studied, despite prolonged use of high doses. Since we noted three cases of fatal necrotizing fasciitis (NF) in patients treated with TCS for BP over a one-year period in our institution, we decided to analyse the frequency of cutaneous infections in all BP patients hospitalized in our department. PATIENTS AND METHODS: In this retrospective single-centre study, all files of patients presenting BP treated with TCS and hospitalized between April 2008 and April 2009 were reviewed. When the clinical file indicated a cutaneous infectious problem, bacteriological data were requested from the bacteriology laboratory. For each patient, clinical data, history, ongoing treatment, type of cutaneous infectious complication, general symptoms and details of outcome were collected. RESULTS: In the 30 files studied, we found ten cutaneous infections in nine patients: minor complication (three cases of impetiginisation), moderate complications (two erysipelas, one lymphangitis with sepsis, one flexor tendon phlegmon with cutaneous fistula), and severe complications with a fatal course (three NF, one of which had involved erysipelas of favourable outcome a few months earlier). These cutaneous complications occurred after various treatment times (ten days to two years) and various dosages of TCS (two-three tubes/day to two tubes every two days). Three of the nine patients with cutaneous infections had diabetes, in particular two of the three patients with FN. In contrast, four of the 21 patients without cutaneous complications had diabetes. Patients with cutaneous infections did not have more extensive BP or receive more TCS than the others. In two of three patients with NF, an immunosuppressant drug (methotrexate or mycophenolate mofetil) had been recently initiated (inferior to one month). The offending organism was Staphylococcus aureus in seven cases (methicillin-resistant in three cases) and Streptococcus A in five cases (three NF, one lymphangitis and one impetiginisation). The outcome was fatal in the three cases of NF but was favourable with local and/or systemic antibiotic therapy in the remaining cases. CONCLUSION: In this study, we noted cutaneous superinfection in nine of 30 (30%) patients receiving topical corticosteroids for bullous pemphigoid, among which were three cases of fatal NF due to streptococcus A (10%). The infectious risks associated with TCS must not be neglected, particularly since treated patients are old and fragile, and frequently have multiple well-known risk factors for NF (e.g. extensive lesions, diabetes, etc.). In the event of signs of cutaneous superinfection, especially in cases of diabetes and prolonged TCS treatment, bacteriological analysis should be conducted. Adequate treatment should be initiated without delay, especially in cases of beta-haemolytic streptococcal infection.