A flickering cutaneous lesion occurring after an insect bite
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ABSTRACT:
SUBMITTER: Hodde T
PROVIDER: S-EPMC8572353 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Nocardia is a genus of aerobic actinomycetes that are usually responsible for opportunistic infection in immunocompromised patients. Less frequently nocardiosis can interest immunocompetent population, causing especially primary cutaneous infections. Cutaneous involvement by Nocardia spp. may occur mostly as one of four clinical manifestations: superficial cellulitis or abscess, mycetoma, lymphocutaneous (also defined "sporotrichoid") infection and secondary cutaneous involvement from systemic disease. Infections usually present after minor local injury, especially in traumatic outdoor activities (e.g. gardeners, farmers, road accidents), with subsequent environmental contamination of the wound. In sporadic cases cutaneous infection follows an insect bite. Microbiological diagnosis is often difficult to obtain and N. brasiliensis is the species isolated in most cases (80%). We present the case of a 45-year-old female with fever and a painful and necrotizing lesion on her right leg with secondary ascending lesions occurred on the homolateral knee and consensual groin lymphadenopathy after insect sting (maybe a spider bite). Cultures on skin biopsy identified Nocardia brasiliensis. Infection was completely healed after 5 months of targeted antibiotic therapy. In addition, we performed a literature review of all cutaneous nocardiosis cases in immunocompetent individuals, finding that only in 22 cases the infection presented after insect bite; in most of these cases lymphocutaneous manifestation was seen and N. brasiliensis was the Nocardia species isolated. Our case, along with others in literature, reveals that the real burden of soft-tissues nocardiosis seems low but probably many cases might go undiagnosed because of difficulties in microbiology diagnosis. Primary cutaneous nocardiosis should be included in the diagnostic pathway in cases of cellulitis following insect bite or sting, especially when localized to extremities.
| S-EPMC9177186 | biostudies-literature
Project description:Bite force is a decisive performance trait in animals because it plays a role for numerous life history components such as food consumption, inter- and intraspecific interactions, and reproductive success. Bite force has been studied across a wide range of vertebrate species, but only for 32 species of insects, the most speciose animal lineage. Here we present the insect bite force database with bite force measurements for 654 insect species covering 476 genera, 111 families, and 13 orders with body lengths ranging from 3.76 to 180.12 mm. In total we recorded 1906 bite force series from 1290 specimens, and, in addition, present basal head, body, and wing metrics. As such, the database will facilitate a wide range of studies on the characteristics, predictors, and macroevolution of bite force in the largest clade of the animal kingdom and may serve as a basis to further our understanding of macroevolutionary processes in relation to bite force across all biting metazoans.
| S-EPMC10781734 | biostudies-literature
Project description:BackgroundGenetic and epidemiologic evidence suggests that in horses, as in other species, different manifestations of hypersensitivity may occur together.HypothesisHorses affected with insect bite hypersensitivity (IBH) show airway hyperreactivity (AH) to inhaled histamine, even in the absence of overt clinical signs of equine asthma (EA).AnimalsTwenty-two healthy controls (group C), 24 horses suffering from IBH alone (group IBH), and 23 horses suffering from IBH and EA (group IBH/EA).MethodsThe clinical histories were assessed using 2 standardized questionnaires, the Horse Owner Assessed Respiratory Signs Index (HOARSI), and IBH scoring. Horses were classified as EA-affected if their HOARSI was >1 and as IBH-affected if IBH score was >0. Confounding disorders were excluded by clinical examination. The arterial partial pressure of oxygen (PaO2 ) was measured and flowmetric plethysmography used to assess airway reactivity to increasing doses of inhaled histamine.ResultsThe median histamine provocation concentration (PC) when ∆flow values increased by 35% (PC35) was significantly higher in group C (5.94 [1.11-26.33] mg/mL) compared to group IBH (2.95 [0.23-10.13] mg/mL) and group IBH/EA (2.03 [0.43-10.94] mg/mL; P < 0.01). The PC50 and PC75 showed very similar differences between groups. Furthermore, PaO2 was significantly lower in group IBH (84 ± 8 mmHg) and group IBH/EA (78 ± 11 mmHg) compared to group C (89 ± 6 mmHg; P < 0.01).Conclusions and clinical importanceIBH is associated with AH and decreased PaO2 , even in the absence of overt respiratory clinical signs.
| S-EPMC5697210 | biostudies-literature
Project description:In this study, we used proteomics and biological network analysis to evaluate the potential biological processes and components present in the identified proteins of biopsies from cutaneous leishmaniasis (CL) patients infected by Leishmania braziliensis in comparison with normal skin. We identified 59 proteins differently expressed in samples from infected and normal skin. Biological network analysis employing identified proteins showed the presence of networks that may be involved in the cell death mediated by cytotoxic T lymphocytes. After immunohistochemical analyses, the expression of caspase-9, caspase-3, and granzyme B was validated in the tissue and positively correlated with the lesion size in CL patients. In conclusion, this work identified differentially expressed proteins in the inflammatory site of CL, revealed enhanced expression of caspase-9, and highlighted mechanisms associated with the progression of tissue damage observed in lesions.
| S-EPMC4291685 | biostudies-literature
Project description:The current study details efficient lesion-free cutaneous vaccination via vaccine delivery into an array of micropores in the skin, instead of bolus injection at a single site. Such delivery effectively segregated vaccine-induced inflammation, resulting in rapid resolution of the inflammation, provided that distances between any two micropores were sufficient. When the inoculation site was treated by FDA-approved nonablative fractional laser (NAFL) before insertion of a PR8 model influenza vaccine-packaged, biodegradable microneedle array (MNs), mice displayed vigorous antigen-uptake, eliciting strong Th1-biased immunity. These animals were completely protected from homologous viral challenges, and fully or partially protected from heterologous H1N1 and H3N2 viral challenges, whereas mice receiving MNs alone suffered from severe illnesses or died of similar viral challenges. NAFL-mediated adjuvanicity was ascribed primarily to dsDNA and other "danger" signals released from laser-damaged skin cells. Thus, mice deficient in dsDNA-sensing pathway, but not Toll like receptor (TLR) or inflammasome pathways, showed poor responses to NAFL. Importantly, with this novel approach both mice and swine exhibited strong protective immunity without incurring any appreciable skin irritation, in sharp contrast to the overt skin irritation caused by intradermal injections. The effective lesion-free cutaneous vaccination merits further clinical studies.
| S-EPMC4413338 | biostudies-literature
Project description:BackgroundInsect bite hypersensitivity (IBH) is the most common seasonal pruritic allergic dermatitis of horses occurring upon insect bites. In recent years, a major role for IL-31 in allergic pruritus of humans, monkeys, dogs, and mice was acknowledged. Here, we investigate the role of IL-31 in IBH of horses and developed a therapeutic vaccine against equine IL-31 (eIL-31).MethodsIL-31 levels were quantified in allergen-stimulated peripheral blood mononuclear cells (PBMCs) and skin punch biopsies of IBH lesions and healthy skin from IBH-affected and healthy horses. The vaccine consisted of eIL-31 covalently coupled to a virus-like particle (VLP) derived from cucumber mosaic virus containing a tetanus toxoid universal T-cell epitope (CuMVTT). Eighteen IBH-affected horses were recruited and immunized with 300 μg of eIL-31-CuMVTT vaccine or placebo and IBH severity score was recorded.ResultsIL-31 was increased in PBMCs and exclusively detectable in skin lesions of IBH-affected horses. Vaccination against eIL-31 reduced delta clinical scores when compared to previous untreated IBH season of the same horses and to placebo-treated horses in the same year. The vaccine was well tolerated without safety concerns throughout the study.ConclusionTH2-derived IL-31 is involved in IBH pathology and accordingly the immunotherapeutic vaccination approach targeting IL-31 alleviated clinical scores in affected horses.
| S-EPMC7217000 | biostudies-literature
Project description:BackgroundMany common and relevant diseases affecting equine welfare have yet to be tested regarding structural variants such as copy number variations (CNVs). CNVs make up a substantial proportion of total genetic variability in populations of many species, resulting in more sequence differences between individuals than SNPs. Associations between CNVs and disease phenotypes have been established in several species, but equine CNV studies have been limited. Aim of this study was to identify CNVs and to perform a genome-wide association (GWA) study in Friesian horses to identify genomic loci associated with insect bite hypersensitivity (IBH), a common seasonal allergic dermatitis observed in many horse breeds worldwide.ResultsGenotypes were obtained using the Axiom® Equine Genotyping Array containing 670,796 SNPs. After quality control of genotypes, 15,041 CNVs and 5350 CNV regions (CNVRs) were identified in 222 Friesian horses. Coverage of the total genome by CNVRs was 11.2% with 49.2% of CNVRs containing genes. 58.0% of CNVRs were novel (i.e. so far only identified in Friesian horses). A SNP- and CNV-based GWA analysis was performed, where about half of the horses were affected by IBH. The SNP-based analysis showed a highly significant association between the MHC region on ECA20 and IBH in Friesian horses. Associations between the MHC region on ECA20 and IBH were also detected based on the CNV-based analysis. However, CNVs associated with IBH in Friesian horses were not often in close proximity to SNPs identified to be associated with IBH.ConclusionsCNVs were identified in a large sample of the Friesian horse population, thereby contributing to our knowledge on CNVs in horses and facilitating our understanding of the equine genome and its phenotypic expression. A clear association was identified between the MHC region on ECA20 and IBH in Friesian horses based on both SNP- and CNV-based GWA studies. These results imply that MHC contributes to IBH sensitivity in Friesian horses. Although subsequent analyses are needed for verification, nucleotide differences, as well as more complex structural variations like CNVs, seem to contribute to IBH sensitivity. IBH should be considered as a common disease with a complex genomic architecture.
| S-EPMC6065148 | biostudies-literature
Project description:The immunological mechanisms explaining development of an allergy in some individuals and not in others remain incompletely understood. Insect bite hypersensitivity (IBH) is a common, seasonal, IgE-mediated, pruritic skin disorder that affects considerable proportions of horses of different breeds, which is caused by bites of the insect Culicoides obsoletus (C. obsoletus). We investigated the allergen-specific immune status of individual horses that had either been diagnosed to be healthy or to suffer of IBH. Following intradermal allergen injection, skin biopsies were taken of IBH-affected and healthy ponies and cytokine expression was determined by RT-PCR. In addition, allergen-specific antibody titers were measured and cytokine expression of in vitro stimulated, allergen-specific CD4 T-cells was determined. 24 hrs after allergen injection, a significant increase in mRNA expression of the type-2 cytokine IL-4 was observed in the skin of IBH-affected Shetland ponies. In the skin of healthy ponies, however, an increase in IFNγ mRNA expression was found. Analysis of allergen-specific antibody titers revealed that all animals produced allergen-specific antibodies, and allergen-specific stimulation of CD4 T-cells revealed a significant higher percentage of IFNγ-expressing CD4 T-cells in healthy ponies compared to IBH-affected ponies. These data indicate that horses not affected by IBH, in contrast to the so far established dogma, are not immunologically ignorant but have a Th1-skewed allergen-specific immune response that appears to protect against IBH-associated symptoms. To our knowledge this is the first demonstration of a natural situation, in which an allergen-specific immune skewing is protective in an allergic disorder.
| S-EPMC4406554 | biostudies-literature
Project description:We report 3 cases of Queensland tick typhus (QTT) and 1 case of African tick bite fever in which the causative rickettsiae were detected by PCR of eschar and skin lesions in all cases. An oral mucosal lesion in 1 QTT case was also positive.
| S-EPMC2727311 | biostudies-literature
Project description:IntroductionDermoscopic findings are used to diagnose and evaluate disease activity in patients with cutaneous lupus erythematosus (CLE).ObjectivesThis study aimed to characterize the dermoscopic features of discoid LE (DLE) and LE tumidus (LET) by lesion duration and CLE Disease Area and Severity Index (CLASI) scores and to examine the dermoscopic findings of lesions in different locations in DLE patients.MethodsDermoscopic findings (follicular features, perifollicular surface, interfollicular features, and vessel pattern) were assessed and lesion duration (≤12 and >12 months) and CLASI scores (grouped as mild or moderate) were calculated. DLE lesion locations were categorized as, non-scalp, scalp and lip.ResultsForty-eight dermoscopic images from 35 DLE and 4 LET patients were analyzed. The most common dermoscopic findings in non-scalp DLE were follicular keratotic plugs (82.8%) and white scales (69%). In scalp DLE (n=9), the most common findings were absent follicular openings (77.8%), white structureless areas (77.8%), and perifollicular scaling (66.7%). All LET patients had pink-white background and linear vessels. Follicular plugs, peripheral pigmentation, and polymorphous vessels were lower in patients with mild CLASI activity than moderate activity (P = 0.036, 0.039, and 0.019, respectively). Fibrotic white dots, honeycomb pigment pattern, and blue-gray dots/globules were lower in those with mild CLASI damage scores than moderate damage (P = 0.010, 0.010, and 0.020, respectively). Peripheral pigmentation was more common in patients with lesion duration ≤12 months, while blue-gray dots/globules were more common with lesion durations >12 months.ConclusionsCertain dermoscopic features may facilitate the differential diagnosis of DLE and LET.
| S-EPMC10868886 | biostudies-literature