Peripheral neuropathy in acrodermatitis chronica atrophicans - effect of treatment

Lyme Neuroborreliosis—Significant Local Variations in Incidence within a Highly Endemic Region in Sweden

The aim of this study was to perform a detailed epidemiological overview of Lyme neuroborreliosis (LNB) 2008–2021 in a highly Lyme borreliosis-endemic area in Sweden using a geographic information system (GIS). Diagnosis of LNB was based on clinical symptoms and analysis of cerebrospinal fluid (CSF) according to European guidelines. From laboratory databases and medical records, we detected all patients with CSF pleocytosis and intrathecal anti-Borrelia antibody production and listed clinical features. The distribution of LNB cases within Kalmar County, Sweden was investigated using GIS. In total, 272 cases of definite LNB were confirmed with an average yearly incidence of 7.8/100,000. Significant differences in incidence were noted between children 0–17 years (16/100,000) and adults 18+ years (5.8/100,000) (p < 0.001), between rural (16/100,000) and urban areas (5.8/100,000) (p < 0.001) and between selected municipalities (p < 0.001). Distinct clinical differences in presentation of LNB were also noted between children and adults. Thus, the incidence of LNB varies significantly locally and in relation to age, and clinical presentation shows differences between children and adults. Surveillance of LNB and knowledge of local epidemiological conditions may facilitate preventive measures.

Methodological Quality Assessment with the AGREE II Scale and a Comparison of European and American Guidelines for the Treatment of Lyme Borreliosis: A Systematic Review

BACKGROUND

Most European and American countries recently updated their guidelines on Lyme borreliosis (LB). The aim of this study was to provide a comparative overview of existing guidelines on the treatment of LB in Europe and America and to assess the methodological quality of their elaboration.

METHODS

A systematic search was carried out in MEDLINE, Google Scholar, and the national databases of scientific societies from 2014 to 2020. Quality was assessed by two independent reviewers using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool.

RESULTS

Twelve guidelines were included. The scores for the AGREE II domains (median ± IQR) were: overall assessment 100 ± 22, scope and purpose 85 ± 46, stakeholder involvement 88 ± 48, rigour of development 67 ± 35, clarity of presentation 81 ± 36, applicability 73 ± 52 and editorial independence 79% ± 54%. Cohen's weighted kappa showed a high agreement (K = 0.90, 95%CI 0.84-0.96). Guidelines were quite homogeneous regarding the recommended molecules (mostly doxycycline in the first intention and ceftriaxone in the second intention), their duration (10 to 28 days), and their dosage. The differences were due to the lack of well-conducted comparative trials. The International Lyme and Associated Diseases Society (ILADS) guidelines were the only ones to suggest longer antibiotics based on an expert consensus.

CONCLUSION

European and American guidelines for the treatment of LB were quite homogeneous but based on moderate- to low-evidence studies. Well-conducted comparative trials are needed to assess the best molecules, the optimal duration and the most effective doses.

Confirmed cases of Neuroborreliosis with involvement of peripheral nervous system: Description of a cohort

The manifestations of borreliosis in the peripheral nervous system (PNS) remain poorly described. As the symptoms of neuroborreliosis can be reversed with timely introduction of antibiotics, early identification could avoid unnecessary axonal loss. Our aim was to describe the characteristics of confirmed neuroborreliosis cases involving the PNS diagnosed between 2007 and 2017 in our neuromuscular disease center in a nonendemic area (La Pitié-Salpêtrière Hospital, Paris, France).Neuroborreliosis was defined as follows: compatible neurological symptoms without other cause of neuropathy; cerebrospinal fluid and serum analysis (positive serological tests with ELISA, confirmed by Western Blot); and improvement of symptoms with adapted antibiotherapy. All the patients consulting in our center between 2007 and 2017 underwent electrophysiological study.Sixteen confirmed cases of neuroborreliosis involving the PNS were included: 10 cases of meningoradiculoneuritis, 4 of axonal neuropathy, and 2 of demyelinating neuropathy (one acute and one chronic). Only 4 (25%) patients reported tick bites. Meningoradiculoneuritis was characterized by lymphocytic meningitis, intense pain, cranial nerve palsy, and contrast enhancement of nerve roots on imagery. The patients with axonal neuropathy presented sensory symptoms with intense pain but no motor deficit and meningitis was rare. Nerve biopsy of 1 patient revealed lymphocytic vasculitis. Electrophysiological testing showed sensory or sensorimotor axonal neuropathy (3 subacute and 1 chronic) of the lower limbs, with asymmetrical neuropathy in 1 patients, symmetrical neuropathy in one and monomelic sensory mononeuritis multiplex in another. We also found 1 case of acute demyelinating neuropathy, treated with antibiotherapy and immunoglobulins, and 1 chronic demyelinating neuropathy. Overall, diaphragmatic paralysis was frequent (18.6%). Antibiotherapy (mostly ceftriaxone 3-4 weeks) resulted in symptom resolution.This series gives an updated overview of the peripheral complications of neuroborreliosis to help identify this disease so that timely treatment could avoid axonal loss.

Lyme borreliosis: diagnosis and management

Lyme borreliosis is the most common vectorborne disease in the northern hemisphere. It usually begins with erythema migrans; early disseminated infection particularly causes multiple erythema migrans or neurologic disease, and late manifestations predominantly include arthritis in North America, and acrodermatitis chronica atrophicans (ACA) in Europe. Diagnosis of Lyme borreliosis is based on characteristic clinical signs and symptoms, complemented by serological confirmation of infection once an antibody response has been mounted. Manifestations usually respond to appropriate antibiotic regimens, but the disease can be followed by sequelae, such as immune arthritis or residual damage to affected tissues. A subset of individuals reports persistent symptoms, including fatigue, pain, arthralgia, and neurocognitive symptoms, which in some people are severe enough to fulfil the criteria for post-treatment Lyme disease syndrome. The reported prevalence of such persistent symptoms following antimicrobial treatment varies considerably, and its pathophysiology is unclear. Persistent active infection in humans has not been identified as a cause of this syndrome, and randomized treatment trials have invariably failed to show any benefit of prolonged antibiotic treatment. For prevention of Lyme borreliosis, post-exposure prophylaxis may be indicated in specific cases, and novel vaccine strategies are under development.

Guidelines for diagnosis and treatment in neurology - Lyme neuroborreliosis

Lyme borreliosis is the most common tick-borne infectious disease in Europe. A neurological manifestation occurs in 3–15% of infections and can manifest as polyradiculitis, meningitis and (rarely) encephalomyelitis.

This S3 guideline is directed at physicians in private practices and clinics who treat Lyme neuroborreliosis in children and adults.

Twenty AWMF member societies, the Robert Koch Institute, the German Borreliosis Society and three patient organisations participated in its development. A systematic review and assessment of the literature was conducted by the German Cochrane Centre, Freiburg (Cochrane Germany).

The main objectives of this guideline are to define the disease and to give recommendations for the confirmation of a clinically suspected diagnosis by laboratory testing, antibiotic therapy, differential diagnostic testing and prevention.

A foot tumour as late cutaneous Lyme borreliosis: a new entity?

Acrodermatitis chronica atrophicans (ACA) is the late cutaneous form of Lyme borreliosis. The early inflammatory phase manifests with a bluish-red discoloration and doughy swelling of the skin. The atrophic phase represents a late-phase process with red discoloration, and a thin and wrinkled appearance of the skin. We present a patient who exhibited a previously undescribed form of late cutaneous Lyme borreliosis (LCLB) with a foot tumour. A 64-year-old woman had a large tumorous lesion on the right sole. The tumour size and deformation of the feet made wearing shoes difficult. On skin histology, a granulomatous lymphohistiocytic infiltrate with plasma cells was noticed. In fact, the patient recalled tick bites 2 or 3 years before. Borrelia burgdorferi (Bb) serology was highly positive and a polymerase chain reaction analysis on the skin biopsy detected Bb sensu lato, genospecies B. afzelii. We diagnosed LCLB and antibiotics were prescribed. On the more recent examination, the tumour had totally disappeared; the skin was atrophic and dry with only few scales. We report an atypical case of European LCLB, suggesting that ACA is not the only possible presentation of LCLB. The diagnosis of ACA is often clinically missed for months or years, and may be mistaken at the inflammation phase for vascular disorders, erysipelas or bursitis/arthritis, and at the atrophic phase for lichen sclerosus atrophicus, morphoea or anetoderma. To our knowledge, no such tumorous LCLB has previously been described.

A critical appraisal of the mild axonal peripheral neuropathy of late neurologic Lyme disease

In older studies, a chronic distal symmetric sensory neuropathy was reported as a relatively common manifestation of late Lyme disease in the United States. However, the original papers describing this entity had notable inconsistencies and certain inexplicable findings, such as reports that this condition developed in patients despite prior antibiotic treatment known to be highly effective for other manifestations of Lyme disease. More recent literature suggests that this entity is seen rarely, if at all. A chronic distal symmetric sensory neuropathy as a manifestation of late Lyme disease in North America should be regarded as controversial and in need of rigorous validation studies before acceptance as a documented clinical entity.

Long-term Follow-up of Patients With Lyme Disease: Longitudinal Analysis of Clinical and Quality-of-life Measures

BACKGROUND

Lyme disease is the most common vector-borne disease in the United States. Some patients report persistent or intermittent subjective symptoms of mild to moderate intensity after antibiotic treatment for Lyme disease. We sought to evaluate trends in clinical and quality-of-life (QOL) measures in a cohort of patients with Lyme disease enrolled in a natural history study at the National Institutes of Health from 2001-2014.

METHODS

QOL was measured using the self-administered 36-item Short Form Health Survey (SF-36) during study follow-up. Primary outcomes included mean physical (PCS) and mental (MCS) health QOL composite scores and reporting long-term (≥2 years) symptoms, adjusted for Lyme disease stage and severity at diagnosis.

RESULTS

Overall, 101 patients with an average follow-up time of 3.9 years (range, 0.5-11.3 years) were included. At first visit, overall mean QOL scores were below the US population mean for both PCS (45.6 ± 10.4) and MCS (47.3 ± 11.5) but increased to just above the national average after 3 years of follow-up for both PCS (50.7 ± 9.6) and MCS (50.1 ± 10.0). Baseline QOL scores were lowest in those with late disease (P < 0.01) but also increased by the end of follow-up to national averages. In multivariate analysis, the only factors significantly associated with long-term symptoms or lower QOL scores were other comorbidities unrelated to Lyme disease.

CONCLUSIONS

Comorbid conditions can play a role in the reporting of long-term symptoms and overall QOL of Lyme disease patients and should be considered in the evaluation of these patients.

CLINICAL TRIALS REGISTRATION

NCT00028080.

Lyme neuroborreliosis-epidemiology, diagnosis and management

Lyme disease, caused by the Borrelia burgdorferi bacterium, is the most common vector-borne disease in the northern hemisphere. The clinical presentation varies with disease stage, and neurological manifestations (often referred to as Lyme neuroborreliosis) are reported in up to 12% of patients with Lyme disease. Most aspects of the epidemiology, clinical manifestation and treatment of Lyme neuroborreliosis are well known and accepted; only the management of so-called chronic Lyme disease is surrounded by considerable controversy. This term is used for disparate patient groups, including those who have untreated late-stage infection (for example, late neuroborreliosis), those with subjective symptoms that persist after treatment (termed 'post-treatment Lyme disease syndrome' [PTLDS]), and those with unexplained subjective complaints that may or may not be accompanied by positive test results for B. burgdorferi infection in serum (here called 'chronic Lyme disease'). The incidence of PTLDS is still a matter of debate, and its pathogenesis is unclear, but there is evidence that these patients do not have ongoing B. burgdorferi infection and, thus, do not benefit from additional antibiotic therapy. Chronic Lyme disease lacks an accepted clinical definition, and most patients who receive this diagnosis have other illnesses. Thus, a careful diagnostic work-up is needed to ensure proper treatment.

Chronic Lyme; diagnostic and therapeutic challenges

In this review, we aim to discuss the definition, clinical and laboratory features, diagnostics, and management of chronic Lyme. Chronic Lyme is a rare condition caused by long-lasting and ongoing infection with the spirochete Borrelia burgdorferi (Bb). The most common manifestations are progressive encephalitis, myelitis, acrodermatitis chronica atrophicans with or without neuropathy, and arthritis. Chronic Lyme is not considered to present with isolated subjective symptoms. Direct detection of Bb has low yield in most manifestations of chronic Lyme, while almost 100% of the cases are seropositive, that is, have detectable Bb IgG antibodies in serum. Detection of Bb antibodies only with Western blot technique and not with ELISA and detection of Bb IgM antibodies without simultaneous detection of Bb IgG antibodies should be considered as seronegativity in patients with long-lasting symptoms. Patients with chronic Lyme in the nervous system (neuroborreliosis) have, with few exceptions, pleocytosis and production of Bb antibodies in their cerebrospinal fluid. Strict guidelines should be applied in diagnostics of chronic Lyme, and several differential diagnoses, including neurological disease, rheumatologic disease, post-Lyme disease syndrome, chronic fatigue syndrome, and psychiatric disease, should be considered in the diagnostic workup. Antibiotic treatment with administration route and dosages according to current guidelines are recommended. Combination antimicrobial therapy or antibiotic courses longer than 4 weeks are not recommended. Patients who attribute their symptoms to chronic Lyme on doubtful basis should be offered a thorough and systematic diagnostic approach, and an open and respectful dialogue.

Lyme neuroborreliosis

Lyme neuroborreliosis (LNB) designates the nervous system disorders caused by the tick-borne spirochete Borrelia burgdorferi (Bb). The clinical syndromes are usually distinct and are classified as early and the rare late or chronic LNB. Early LNB occurs 3-6 weeks after infection most frequently as a lymphocytic meningoradiculoneuritis (LMR). Symptoms are mainly due to a painful sensory radiculitis and a multifocal motor radiculo-neuritis. Fifty percent have cranial nerve involvement predominantly uni- or bilateral facial nerve palsies. Meningitic symptoms occur primarily in children. Nerve biopsies, autopsies, animal models, and nerve conduction studies showed that the pathology is a lymphocytic perineuritis leading to multisegmental axonal injury of nerve roots, spinal ganglia, and distal nerve segments. Due to meningeal and root inflammation cerebrospinal fluid (CSF) shows lymphocytic inflammation. The only evidence that Bb causes peripheral neuropathy without CSF inflammation is seen in patients with acrodermatitis chronica atrophicans (ACA), a chronic dermatoborreliosis. In the rare chronic or late LNB the pathology and thus the clinical presentation is primarily due to chronic meningitis and meningovascular CNS involvement, whereas the peripheral nervous system is not primarily affected. In early and late LNB the diagnosis is based on a characteristic clinical appearance and CSF inflammation with Bb-specific intrathecal antibody production. Both conditions, but not the ACA-associated neuropathy, respond to antibiotic therapy.

Skin manifestations of lyme borreliosis: diagnosis and management

Lyme borreliosis is a multisystem infectious disease caused by tick-transmitted spirochetes of the Borrelia burgdorferi sensu lato complex. The three characteristic cutaneous manifestations are erythema migrans, borrelial lymphocytoma, and acrodermatitis chronica atrophicans. Erythema migrans occurs in acute Lyme borreliosis, lymphocytoma is a subacute lesion, and acrodermatitis is the typical manifestation of late Lyme borreliosis. Clinical appearances of erythema migrans and lymphocytoma (when located on the ear or breast) are characteristic, whereas acrodermatitis is often confused with vascular conditions. The diagnosis of erythema migrans is made clinically. Serologic analyses often yield false-negative results and are not required for the diagnosis. However, serologic proof of the diagnosis in lymphocytoma (approximately 90% positive) and acrodermatitis (100% positive) is mandatory. Histopathologic examination often adds substantial information in patients with skin manifestations of Lyme borreliosis and is recommended in clinically (and serologically) undecided cases of erythema migrans or lymphocytoma and is obligatory in acrodermatitis. Polymerase chain reaction for Borrelia-specific DNA (rather than culture of the spirochete) and immunohistochemical investigations (lymphocytoma) are sometimes necessary adjuncts for the diagnosis. Antibacterial treatment is necessary in all patients to eliminate the spirochete, cure current disease, and prevent late sequelae. Oral doxycycline, also effective against coinfection with Anaplasma phagocytophilum, is the mainstay of therapy of cutaneous manifestations of Lyme borreliosis. Other first-line antibacterials are amoxicillin and cefuroxime axetil. Erythema migrans is treated for 2 weeks, lymphocytoma for 3-4 weeks, and acrodermatitis for at least 4 weeks.

Chronic Lyme disease: a review

Studies have shown that most patients diagnosed with chronic Lyme disease either have no objective evidence of previous or current infection with Borrelia burgdorferi or are patients who should be classified as having post-Lyme disease syndrome, which is defined as continuing or relapsing nonspecific symptoms (such as fatigue, musculoskeletal pain, and cognitive complaints) in a patient previously treated for Lyme disease. Despite extensive study, there is currently no clear evidence that post-Lyme disease syndrome is caused by persistent infection with B burgdorferi. Four randomized placebo-controlled studies have shown that antibiotic therapy offers no sustained benefit to patients who have post-Lyme disease syndrome. These studies also showed a substantial placebo effect and a significant risk of treatment-related adverse events. Further research to elucidate the mechanisms underlying persistent symptoms after Lyme disease and controlled trials of new approaches to the treatment and management of these patients are needed.

Infectious neuropathy

PURPOSE OF REVIEW

Infectious neuropathy affects a large number of people worldwide. There is evidence of direct involvement of nerves by the infective agent, from the immune reaction of the patient or secondary to the toxicity of the drugs used during treatment. This group of neuropathies is often treatable or preventable.

RECENT FINDINGS

There is a complex clinical picture of the neuropathy of leprosy, different pathological features and immunological mechanisms. If the skin is unaffected in leprosy it is not always easy to demonstrate that the neuropathy is due to leprosy. Peripheral neuropathy in patients with chronic infection with hepatitis C virus may be due to the virus, the development of vasculitis or direct neurotoxic effects of the treatment. Peripheral neuropathy has become the chief neurological syndrome in individuals infected with HIV-1. The antiretroviral therapies themselves can cause peripheral neuropathies clinically indistinguishable from those caused by the virus. The occurrence of chronic polyneuropathy as a late manifestation in Lyme disease is extremely rare and is not well understood.

SUMMARY

Although infectious neuropathies are very frequent, mainly in developing countries, further studies are needed to elucidate their mechanisms of action, focusing on preventive interventions.

Le traitement des phases secondaires et tertiaires de la borréliose de Lyme

The treatment of secondary and tertiary Lyme borreliosis is difficult because of antibiotic lack of efficacy. This fact may be explained by several factors: the specific pathophysiology, involving not only the presence of bacteria, but also immunological reactions. There is no specific method of diagnosis resulting in difficulties for good indication of treatment and to evaluate treatment efficacy. The literature review shows that ceftriaxone and doxycycline are the two most efficient antibiotics in this indication. Even if the methodology of the published studies is not always convincing, these two antibiotics proved their efficacy in articular as well as in neurological forms of the disease. In the late stage of borreliosis, antibiotics are less efficient. Various treatment modalities with different dosage or duration of treatment cannot let us conclude on a convincing regimen.

Sur quels éléments cliniques et épidémiologiques faut-il évoquer le diagnostic de la borréliose de Lyme? Aspects neurologiques et psychiatriques au cours de la maladie de Lyme

Lyme disease is associated with various systemic and neurological manifestations. The neurological and psychiatric manifestations of Lyme disease are more frequently observed during its secondary phase (stage 2) than during its late tertiary phase (stage 3). In stage 2, cerebrospinal fluid and bacterial tests are consistent with the ongoing infection. Painful meningoradiculitis, encephalomyelitis and encephalitis, and symptoms of depression are the most characteristic at this stage. The diagnosis should be based on the association of clinical, epidemiological, and biological features. Adequate treatment usually leads to recovery. In stage 3 of the disease, the link between neurological manifestations and initial infection is uncertain. Distal axonal polyneuropathy and chronic encephalopathy are the most frequently reported presentations.

Traitement et suivi des phases secondaire et tertiaire de la borréliose de Lyme

The aim of this review was to analyze the current strategies of treatment and follow-up of disseminated and late Lyme borreliosis. A comprehensive search was performed using the Medline database. Only relevant reviews, expert guidelines and randomized controlled clinical trials were selected and, if necessary, open trials. Major drugs used in these studies were amoxicillin, doxycycline, penicillin G, and ceftriaxone. Oral administration of antibiotics was preferred in Lyme arthritis whereas parenteral drugs were mostly used in neuroborreliosis. The treatment duration usually ranged from 14 to 30 days. Prolonged antibiotic courses recommended by some authors in post-Lyme syndromes were not validated by several randomized placebo controlled studies. Follow up patterns were analyzed in order to determine possible prognosis parameters allowing to distinguih active Borrelia burgdorferi infection from a sequel of infection.

Aspects neurologiques et psychiatriques au cours de la maladie de Lyme

The neurological and psychiatric manifestations of Borrelia burgdorferi sensu lato are so numerous that Borrelia is also called the "new great imitator". Thus knowing about the multiple clinical aspects of neuroborreliosis is necessary for the clinician. We reviewed literature for "classical" neuroborreliosis such as acute meningoradiculitis or chronicle encephalomyelitis, but also for encephalitis, myelitis, polyneuritis, radiculitis and more controversial disorders such as chronic neurological disorders, ischemic and hemorrhagic stroke, and motor neuron disease. We specified every time on which basis each disorder was attributed to Lyme disease, particularly if European or American criteria were met. Every part of the nervous system can be involved: from central to peripheral nervous system, and even muscles. In endemic areas, Lyme serology must be assessed in case of unexplained neurological or psychiatric disorder. In case of positive serology, CSF assessment with intrathecal anti-Borrelia antibody index will be more efficient to prove the diagnosis.

Lyme borreliosis

Lyme borreliosis is a tick-borne infectious disease caused by the spirochaetes Borrelia burgdorferi, B. garinii and B. afzelii. It comprises a wide spectrum of symptoms affecting skin, musculoskeletal system, heart, eyes, central and peripheral nervous system. The diagnosis is based on clinical findings in combination with detection of specific IgM and/or IgG antibodies. Diagnostic problems arise from patients with non-specific symptoms and positive IgG antibody detection. Adequate antibiotic therapy cures more than 90% of the patients. However, in some patients repeated therapy is necessary and a small number of patients develop chronic arthritis or other features. While there is currently no vaccine available, prevention of tick bite is the most effective prophylaxis.

The clinical assessment, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America

Evidence-based guidelines for the management of patients with Lyme disease, human granulocytic anaplasmosis (formerly known as human granulocytic ehrlichiosis), and babesiosis were prepared by an expert panel of the Infectious Diseases Society of America. These updated guidelines replace the previous treatment guidelines published in 2000 (Clin Infect Dis 2000; 31[Suppl 1]:1-14). The guidelines are intended for use by health care providers who care for patients who either have these infections or may be at risk for them. For each of these Ixodes tickborne infections, information is provided about prevention, epidemiology, clinical manifestations, diagnosis, and treatment. Tables list the doses and durations of antimicrobial therapy recommended for treatment and prevention of Lyme disease and provide a partial list of therapies to be avoided. A definition of post-Lyme disease syndrome is proposed.

Antibiotic treatment of Lyme borreliosis: what is the evidence?

Antibiotic treatment of all disease manifestations after infection with Borrelia sensu lato spp aims at resolving the presenting disease manifestation and preventing late stage disease. The goals are resolution of the preventing manifestation and prevention of the spread of bacteria to prevent late disease like arthritis. Different borrelial species prevail in Europe. The natural disease course of European borreliosis is not well defined and the effect of antibiotic treatment is unclear.

Genotype determines phenotype in experimental Lyme borreliosis

Borrelia burgdorferi sensu lato, the causative organism of Lyme borreliosis, is a heterogeneous group of spirochetes, consisting of at least three pathogenic species. To test the hypothesis that the genetic heterogeneity is the reason for the clinical differences, we investigated whether the experimental disease induced by European isolates is different from that induced by American isolates. Two American isolates of species B. burgdorferi sensu stricto were compared with three European isolates, two of species B. garinii, and one of species B. afzelii. The patterns of infection, immunity, and inflammation induced by the different species was distinctive. Inflammatory cells and levels of antibody in B. garinii- and B. afzelii-infected animals were lower than in B. burgdorferi s.s.-infected animals, whereas levels of spirochetal infection in the skin and nervous system were higher in the former group of animals. These data demonstrate that B. burgdorferi s.s. strains are more infective and inflammatory, whereas B. garinii and B. afzelii strains can survive the adaptive immune response to a greater degree and persist at greater numbers in the skin and nervous system. The results explain to a large extent the disparities between LNB in humans in the United States and Europe.