Panadizo herpético en lactante de 20 meses / Herpetic whitlow in a 20-month-old infant

El panadizo herpético es una lesión cutánea producida por el virus herpes simple, en pediatría especialmente el virus herpes tipo 1. Es una lesión que se debe conocer para evitar realizar un diagnóstico incorrecto e instaurar tratamientos innecesarios o incluso perjudiciales. La presentación clínica habitual es una lesión con vesículas arracimadas, cuya localización típica es en primer o segundo dedo. En los pacientes pediátricos es frecuente que se produzca tras autoinoculación desde una gingivoestomatitis herpética, por lo que ante la sospecha de esta lesión es importante la exploración física completa incluyendo orofaringe. El curso es autorresolutivo aunque en ocasiones puede ser necesario instaurar tratamiento con aciclovir oral. El drenaje de la lesión está contraindicado porque puede llegar a producir una diseminación del virus herpes con graves consecuencia (AU)

Herpetic whitlow is a skin lesion caused by the herpes simplex virus (HSV), usually type 1 in the paediatric population. Providers must be aware of this lesion to avoid making an incorrect diagnosis and initiating unnecessary or even harmful treatments.The usual presentation is a lesion with clustered vesicles, typically located on the first or second toe. In paediatric patients, it is often the result of autoinoculation from HSV gingivostomatitis lesions, so when this lesion is suspected, it is important to carry out a complete physical examination including the oropharynx.The course is self-limiting, although on occasion treatment with oral acyclovir becomes necessary. Drainage of the lesion is contraindicated because it could lead to dissemination of HSV with severe consequences. (AU)

Herpes simplex virus 1 proteins can induce skin inflammation in an atopic dermatitis-like mouse model.

Herpes simplex virus type 1 (HSV-1) can induce in certain individuals with atopic dermatitis (AD) severe cutaneous infections that can spread throughout the entire body, a condition named as AD complicated by eczema herpeticum (ADEH). It has been recently found that ADEH patients can produce specific IgE against HSV-1 proteins, which may contribute to lower protection against HSV-1. However, little is known about the capacity of these HSV-1 proteins to produce an inflammatory response at the skin level. In this study, using a mouse model of AD-like dermatitis, three HSV-1 proteins (glycoprotein D -gD-, glycoprotein B -gB- and VP22) were applied on tape-stripped back skin mice in three exposures periods. Ovalbumin (OVA) and 0.9% NaCl were used as positive and negative controls, respectively. Skin samples were obtained for analysis of specific cell components of skin infiltration. The results showed that the viral protein gD induced a statistically significant increase in the number of dermal infiltrating CD3+, CD4+ cells and mast cells compared with the negative control group. gD was also able to induce epidermal thickening and epidermal infiltration of T cells closely related to the one produced in mice sensitized with OVA. However, VP22 and gB contributed to a lesser extent to skin inflammation. These results showed that proteins from HSV-1, especially gD, can have per se an important T cell and mast cell-driven inflammatory potential at the skin level.

Novel Dermatitis and Relative Viral Nucleic Acid Tissue Loads in a Fin Whale (Balaenoptera physalus) with Systemic Cetacean Morbillivirus Infection.

Cetacean morbilliviruses (CeMVs) are significant causes of mortality in many cetacean species in epizootics and smaller outbreaks. Despite the prominence of skin lesions in seals and terrestrial animals, including humans, affected by other morbilliviruses, they have not been reported in CeMV-infected cetaceans. Here we report CeMV-associated skin lesions in a fin whale (Balaenoptera physalus) with subacute, systemic CeMV infection that live-stranded in Scotland, UK. Grossly, the skin was sloughing in large sheets, presumed due to autolysis, but histological examination showed syncytia, below the dermoepidermal junction, that were strongly immunopositive for morbillivirus antigen, as were syncytia in other organs. By polymerase chain reaction (PCR), the relative load of CeMV-specific RNA was largest in the liver and urinary bladder, even in formalin-fixed, paraffin-wax embedded samples. Levels were low in skin and only detectable in frozen samples. Genetic comparison of the CeMV revealed close alignment with isolates from fin whales from the North Atlantic Ocean and Mediterranean Sea, but that it was distinct from the porpoise CeMV clade. These findings show skin samples can be used to diagnose CeMV infection in cetaceans, highlighting the potential of ante-mortem sampling for monitoring disease in current populations and assessment of changes in host and pathogen genetics.

Ginkgolic Acid Inhibits Herpes Simplex Virus Type 1 Skin Infection and Prevents Zosteriform Spread in Mice.

Herpes simplex virus type 1 (HSV-1) causes a lifelong latent infection with an estimated global prevalence of 66%. Primary and recurrent HSV infections are characterized by a tingling sensation, followed by an eruption of vesicles, which can cause painful erosions. Commonly used antiviral drugs against HSV infection are nucleoside analogues including acyclovir (ACV), famciclovir, and valacyclovir. Although these nucleoside analogues reduce morbidity and mortality in immunocompetent individuals, ACV-resistant HSV strains (ACVR-HSV) have been isolated from immunocompromised patients. Thus, ACVR-HSV infection poses a critical emerging public health concern. Recently, we reported that ginkgolic acid (GA) inhibits HSV-1 by disrupting viral structure, blocking fusion, and inhibiting viral protein synthesis. Additionally, we showed GA affords a broad spectrum of fusion inhibition of all three classes of fusion proteins, including those of HIV, Ebola, influenza A and Epstein Barr viruses. Here we report GA's antiviral activity against HSV-1 skin infection in BALB/cJ mice. GA-treated mice demonstrated a significantly reduced mortality rate and decreased infection scores compared to controls treated with dimethylsulfoxide (DMSO)-vehicle. Furthermore, GA efficiently inhibited ACVR-HSV-1 strain 17+ in vitro and in vivo. Since GA's mechanism of action includes virucidal activity and fusion inhibition, it is expected to work alone or synergistically with other anti-viral drugs, and we anticipate it to be effective against additional cutaneous and potentially systemic viral infections.

Characterization of an alphavirus isolated from a stranded harbor porpoise (Phocoena phocoena) from Alaska.

The family Togaviridae comprises several significant human and veterinary mosquito-borne pathogens. Two togaviruses (genus Alphavirus) have been previously identified in association with marine mammals, the southern elephant seal virus (SESV) and Eastern equine encephalitis virus (EEEV) from a fatal captive harbor seal infection. Herein we report the ultrastructural and phylogenomic characterization of a novel marine togavirus, the first isolated from a cetacean, an Alaskan harbor porpoise (Phocoena phocoena) displaying ulcerative dermatitis. A skin sample was processed for virus isolation on Vero.DogSLAMtag cells and cytopathic effects (CPE) were observed on primary isolation approximately 20 days post-infection. Transmission electron microscopy of the infected Vero.DogSLAMtag cells revealed typical alphavirus particles budding from both plasma and vacuolar membranes of infected cells. A next-generation sequencing approach was used to determine the near complete genome of the Alaskan harbor porpoise alphavirus (AHPV). Phylogenetic analysis supported the AHPV as the sister species to the SESV, forming a marine mammal alphavirus clade separate from the recognized alphavirus antigenic complexes. Genetic comparison of the protein coding sequence of the AHPV to other alphaviruses demonstrated amino acid identities ranging from 42.1-67.1%, with the highest identity to the SESV. Based on its genetic divergence, we propose the AHPV represents a novel alphavirus species, pending formal proposal to and ratification by the International Committee on Taxonomy of Viruses. The ecological and genetic characteristics of the AHPV and the SESV also suggest they represent a novel antigenic complex within the genus Alphavirus, which we propose to be named the Marine Mammal Virus Complex. The role of the AHPV in the associated harbor porpoise cutaneous pathology, if any, remains unclear. Further research is needed to determine AHPV's route(s) of transmission and potential vectors, host range, prevalence, and pathogenicity in cetaceans including harbour porpoises.

Ischemic stroke and purpuric dermatitis as COVID-19-related complications in a peritoneal dialysis patient.

Patients on dialysis may have an elevated risk of severe coronavirus disease 2019 (COVID-19) and its complications due to their high prevalence of comorbidities. Here we describe the case of an 80-year-old male undergoing peritoneal dialysis with a moderate SARS-CoV-2 infection who developed a purpuric dermatitis and ischemic stroke after successful recovery from his bilateral pneumonia. Erythemato-papular lesions affecting trunk and lower limbs appeared 17 days after the onset of SARS-CoV-2 symptoms. These kind of lesions are an infrequent cutaneous manifestation of COVID-19. The pathology revealed a moderate purpuric dermatitis affecting superficial dermis and corticoesteroids were prescribed achieving complete resolution. Arterial thrombosis affecting cerebellar vermis emerged 30 days after the onset of COVID-19 symptoms. It occurred 5 days after withdrawal of antithrombotic prophylaxis that the patient received from his admission until 2 weeks after discharge. He completely recovered from his paresis and continued on his regular antiaggregation therapy. This is the first case report published of a patient with PD with such COVID-19-related complications. More experience is needed to determine the appropriate length of antithrombotic prophylaxis especially in high-risk individuals.

Cutaneous manifestations in patients with coronavirus disease 2019: clinical and histological findings.

The clinical spectrum of coronavirus disease 2019 is getting wider with the exponential increase of patients worldwide. Initially described with flu-like symptoms, variable cutaneous manifestations have been reported, with only few histopathological descriptions. Detection of the virus in cutaneous samples has been assessed in very few cases until now, and the causative role of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not been proven for every type of cutaneous manifestations yet. We aimed to describe histological features of cutaneous eruptions occurring concomitantly to SARS-CoV-2 infection and assess by immunochemistry and in situ hybridization using RNAscope validation techniques the presence of the virus in skin lesions. We retrieved all skin biopsies received in the departments of pathology and dermatopathology, University Hospital of Strasbourg, performed in hospitalized SARS-CoV-2-infected patients presenting concomitant cutaneous manifestations since March 2020. In situ hybridization and immunostaining using a polyclonal SARS nucleocapsid protein antibody were performed on each sample. Skin biopsies from six patients presenting morbilliform eruption concomitant to SARS-CoV-2 infection were available for evaluation. All six samples showed varying degrees of spongiosis, perivascular inflammatory infiltrates of the dermis, and, for some of them, discrete interface dermatitis. In situ hybridization and immunohistochemistry were negative in all cutaneous samples. Morbilliform rash concomitant to SARS-CoV-2 infection is characterized by mild and unspecific histopathological features with no detectable viral RNA and protein and appears then not to be directly caused by the virus. Even if, at least for a few cases, the differential diagnosis with drug hypersensitivity reaction can be difficult, these cutaneous eruptions seem to rather correspond to paraviral rashes.

Dermatitis infectiva asociada a HTLV-1: dermatosis a tener en cuenta en pacientes de zonas endémicas / Infective dermatitis associated with HTLV-1: Dermatosis to be considered in patients from endemic áreas

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First molecular detection and complete sequence analysis of porcine circovirus type 3 (PCV3) in Peninsular Malaysia.

Porcine circovirus type 3 (PCV3) is a newly emerging virus in the swine industry, first reported recently in 2016. PCV3 assembles into a 2000 bp circular genome; slightly larger than PCV1 (1758-1760 bp), PCV2 (1766-1769 bp) and PCV4 (1770 bp). Apart from being associated with porcine dermatitis and nephropathy syndrome (PDNS), PCV3 has been isolated from pigs with clinical signs of reproductive failures, myocarditis, porcine respiratory disease complex (PRDC) and neurologic disease. Given that PCV3 is increasingly reported in countries including Thailand and U.S. with whom Malaysia shares trade and geographical relationship; and that PCV3 is associated with several clinical presentations that affect productivity, there is a need to study the presence and molecular characteristics of PCV3 in Malaysian swine farms. Twenty-four commercial swine farms, three abattoirs and retail shops in Peninsular Malaysia were sampled using convenience sampling method. A total of 281 samples from 141 pigs, including 49 lung archive samples were tested for PCV3 by conventional PCR. Twenty-eight lung samples from wild boar population in Peninsular Malaysia were also included. Nucleotide sequences were analyzed for maximum likelihood phylogeny relationship and pairwise distances. Results revealed that PCV3 is present in Peninsular Malaysia at a molecular prevalence of 17.02%, with inguinal lymph nodes and lungs showing the highest molecular detection rates of 81.82% and 71.43% respectively. Despite wide reports of PCV3 in healthy animals and wild boars, no positive samples were detected in clinically healthy finishers and wild boar population of this study. PCV3 strain A1 and A2 were present in Malaysia, and Malaysian PCV3 strains were found to be phylogenetically related to Spanish, U.S. and Mexico strains.

Lumpy Skin Disease Is Characterized by Severe Multifocal Dermatitis With Necrotizing Fibrinoid Vasculitis Following Experimental Infection.

Lumpy skin disease is a high-consequence disease in cattle caused by infection with the poxvirus lumpy skin disease virus (LSDV). The virus is endemic in most countries in Africa and an emerging threat to cattle populations in Europe and Asia. As LSDV spreads into new regions, it is important that signs of disease are recognized promptly by animal caregivers. This study describes the gross, microscopic, and ultrastructural changes that occur over time in cattle experimentally challenged with LSDV. Four calves were inoculated with wildtype LSDV and monitored for 19 to 21 days. At 7 days after inoculation, 2 of the 4 cattle developed multifocal cutaneous nodules characteristic of LSD. Some lesions displayed a targetoid appearance. Histologically, intercellular and intracellular edema was present in the epidermis of some nodules. Occasional intracytoplasmic inclusion bodies were identified in keratinocytes. More severe and consistent changes were present in the dermis, with marked histiocytic inflammation and necrotizing fibrinoid vasculitis of dermal vessels, particularly the deep dermal plexus. Chronic lesions consisted of full-thickness necrosis of the dermis and epidermis. Lesions in other body organs were not a major feature of LSD in this study, highlighting the strong cutaneous tropism of this virus. Immunohistochemistry and electron microscopy identified LSDV-infected histiocytes and fibroblasts in the skin nodules of affected cattle. This study highlights the noteworthy lesions of LSDV and how they develop over time.

Molecular and Biological Characterization of a Cervidpoxvirus Isolated From Moose with Necrotizing Dermatitis.

Cervidpoxvirus is one of the more recently designated genera within the subfamily Chordopoxvirinae, with Deerpox virus (DPV) as the only recognized species to date. In this study, the authors describe spontaneous disease and infection in the North American moose (Alces americanus) by a novel Cervidpoxvirus, here named Moosepox virus (MPV). Three 4-month-old moose calves developed a multifocal subacute-to-chronic, necrotizing, suppurative-to-granulomatous dermatitis that affected the face and the extremities. Ultrastructurally, all stages of MPV morphogenesis-that is, crescents, spherical immature particles, mature particles, and enveloped mature virus-were observed in skin tissue. In vitro infection with MPV confirmed that its morphogenesis was similar to that of the prototype vaccinia virus. The entire coding region, including 170 putative genes of this MPV, was sequenced and annotated. The sequence length was 164,258 bp with 98.5% nucleotide identity with DPV (strain W-1170-84) based on the whole genome. The genome of the study virus was distinct from that of the reference strain (W-1170-84) in certain genes, including the CD30-like protein (83.9% nucleotide, 81.6% amino acid), the endothelin precursor (73.2% nucleotide including some indels, 51.4% amino acid), and major histocompatibility class (MHC) class I-like protein (81.0% nucleotide, 68.2% amino acid). This study provides biological characterization of a new Cervidpoxvirus attained through in vivo and in vitro ultrastructural analyses. It also demonstrates the importance of whole-genome sequencing in the molecular characterization of poxviruses identified in taxonomically related hosts.

Rubella Vaccine Persistence Within Cutaneous Granulomas in Common Variable Immunodeficiency Disorder.

Common variable immunodeficiency disorder is a primary immunodeficiency disorder characterized by reduced levels of serum immunoglobulins and impaired antibody response. This condition may be associated with development of noninfectious granulomatous dermatitis of the skin which may be disfiguring and destructive. There are no published guidelines for the treatment of cutaneous granulomas in this patient population. In recent studies, rubella virus-positive cells in granulomas were localized to M2 macrophages which have an important role in wound healing and the secretion of immunoregulatory cytokines. We present a case of treatment-refractory, disfiguring common variable immunodeficiency disorder-associated granulomatous dermatitis. Immunofluorescence microscopy of the biopsy specimen confirmed the presence of rubella vaccine capsid proteins in M2 macrophages within the granuloma, a newly recognized phenomenon in this patient population. This knowledge may serve to identify future therapeutic targets or preventative strategies for granulomatous dermatitis in patients with primary immunodeficiency disorder.

RIP1 kinase activity is critical for skin inflammation but not for viral propagation.

Receptor interacting protein kinase 1 (RIP1) is a critical effector of inflammatory responses and cell death activation. Cell death pathways regulated by RIP1 include caspase-dependent apoptosis and caspase-independent necroptosis. The kinase activity of RIP1 has been associated with a number of inflammatory, neurodegenerative, and oncogenic diseases. In this study, we use the RIP1 kinase inhibitor GNE684 to demonstrate that RIP1 inhibition can effectively block skin inflammation and immune cell infiltrates in livers of Sharpin mutant (Cpdm; chronic proliferative dermatitis) mice in an interventional setting, after disease onset. On the other hand, genetic inactivation of RIP1 (RIP1 KD) or ablation of RIP3 (RIP3 KO) or MLKL (MLKL KO) did not affect testicular pathology of aging male mice. Likewise, infection with vaccinia virus or with mouse gammaherpesvirus MHV68 resulted in similar viral clearance in wild-type, RIP1 KD, and RIP3 KO mice. In summary, this study highlights the benefits of inhibiting RIP1 in skin inflammation, as opposed to its lack of relevance for testicular longevity and the response to certain viral infections.

Infective dermatitis: A purely cutaneous manifestation of HTLV-1 infection.

Infectious dermatitis is a cutaneous manifestation of HTLV-1 infection. Although initially described in children in Jamaica, it is well documented that the disease can also present in adults. The clinical picture is of an oozing dermatitis affecting the scalp, face, retroauricular areas, the neck, and intertrigious areas, such as the axilla and groin. Histologically it has two patterns: a superficial perivascular dermatitis or a lichenoid dermatitis. The epidermal hyperplasia may mimic psoriasis. An important differential diagnosis is with mycosis fungoides, with epidermotropism, alignment of lymphocytes along the epidermal junction, lymphocytes in halo and wiry bundles of collagen in the papillary dermis. An important difference is the lack of marked lymphocytic atypia. The infiltrate is composed of a predominance of CD8-positive lymphocytes, analogous to what is seen in tropical spastic paraparesis. Infectious dermatitis patients may be confused with many common dermatological conditions, such a atopic dermatitis and contact dermatitis. Its diagnosis represent a challenge both to clinicians and dermatopathologists working in endemic areas.

Complete genome sequence of human T-cell lymphotropic type 1 from patients with different clinical profiles, including infective dermatitis.

The HTLV-1 is the first human retrovirus and is associated with several clinical syndromes, however, the pathogenesis of these clinical manifestations is still not fully understood. Furthermore, there are few complete genomes publicly available, about 0.12 complete genomes per 10,000 infected individuals and the databases have a major deficiency of sequences information. This study generated and characterized 31 HTLV-1 complete genomes sequences derived from individuals with Tropical Spastic Paraparesis/HTLV-1-Associated Myelopathy (TSP/HAM), Adult T-cell leukemia/lymphoma (ATL), infective dermatitis associated to HTLV-1 (IDH) and asymptomatic patients. These sequences are associated to clinical and epidemiological information about the patients. The sequencing data generated on Ion Torrent PGM platform were assembled and mapped against the reference HTLV-1 genome. These sequences were genotyped as Cosmopolitan subtype, Transcontinental subgroup. We identified the variants in the coding regions of the genome of the different clinical profiles, however, no statistical relation was detected. This study contributed to increase of HTLV-1 complete genomes in the world. Furthermore, to better investigate the contribution of HTLV-1 mutations for the disease outcome it is necessary to evaluate the interaction of the viral genome and characteristics of the human host.

Genome-Wide CpG Island Methylation Profiles of Cutaneous Skin with and without HPV Infection.

HPV infection is one of the most commonly transmitted diseases among the global population. While it can be asymptomatic, non-genital HPV infection often gives rise to cutaneous warts, which are benign growths arising from the epidermal layer of the skin. This study aimed to produce a global analysis of the ways in which cutaneous wart formation affected the CpG island methylome. The Infinium MethylationEPIC BeadChip microarray was utilized in order to quantitatively interrogate CpG island methylation in genomic DNA extracted from 24 paired wart and normal skin samples. Differential methylation analysis was carried out by means of assigning a combined rank score using RnBeads. The 1000 top-ranking CpG islands were then subject to Locus Overlap Analysis (LOLA) for enrichment of genomic ranges, while signaling pathway analysis was carried out on the top 100 differentially methylated CpG islands. Differential methylation analysis illustrated that the most differentially methylated CpG islands in warts lay within the ITGB5, DTNB, RBFOX3, SLC6A9, and C2orf27A genes. In addition, the most enriched genomic region sets in warts were Sheffield's tissue-clustered DNase hypersensitive sites, ENCODE's segmentation and transcription factor binding sites, codex sites, and the epigenome sites from cistrome. Lastly, signaling pathway analysis showed that the GRB2, GNB1, NTRK1, AXIN1, and SKI genes were the most common regulators of the genes associated with the top 100 most differentially methylated CpG islands in warts. Our study shows that HPV-induced cutaneous warts have a clear CpG island methylation profile that sets them apart from normal skin. Such a finding could account for the temporary nature of warts and the capacity for individuals to undergo clinical remission.

Quantitative real time polymerase chain reaction (qRT-PCR) and RNAscope in situ hybridization (RNA-ISH) as effective tools to diagnose feline herpesvirus-1-associated dermatitis.

BACKGROUND: Felid herpesvirus type 1 (FHV-1)-associated dermatitis is characterized by facial and nasal involvement; clinical and histopathological manifestations may overlap with other dermatitides. OBJECTIVE: To evaluate the realibility of qRT-PCR-2- ΔΔC q and RNAscope in situ hybridization (RNA-ISH) methods to diagnose FHV-1-associated dermatitis, in formalin-fixed paraffin-embedded (FFPE) tissues. ANIMALS: Sixteen FFPE samples from cats with facial dermatitis and four controls were studied. METHODS AND MATERIALS: Based on histopathological features, cases were separated into: Group 1, samples with herpetic dermatitis (four); Group 2, samples with nonherpetic facial dermatitis (six); Group 3, samples with facial dermatitis of ambiguous nature (allergic or viral) (six); and Group 4, samples from healthy cats (four). A relative quantification using the 2- ΔΔC q method was used to estimate the "upregulation" of each FHV-1 target viral gene copies (glycoprotein-B and thymidine-kinase) relative to reference gene. Detection of FHV-1 mRNA was performed using the RNAscope 2.5 detection kit. RESULTS: By 2- ΔΔC q analysis, upregulation of both FHV-1 genes was observed in all samples from Group 1 and two of six from Group 3. No upregulation was identified in samples from groups 2 and 4. Positive mRNA hybridization signal was observed in all cases from Group 1 and two cases of Group 3. No positivity was observed in samples from groups 2 and 4. CONCLUSIONS AND CLINICAL IMPORTANCE: QRT-PCR 2-ΔΔCq analysis and RNA-ISH can identify the FHV-1 genome as causative agent of the associated dermatitis, even where inclusion bodies are not detectable. Both techniques are functional in retrospective studies, have greater specificity than conventional PCR, and may be proposed for research and diagnostic purposes.

Induction of Porcine Dermatitis and Nephropathy Syndrome in Piglets by Infection with Porcine Circovirus Type 3.

Porcine circovirus type 3 (PCV3) is an emerging porcine circovirus that has been associated with porcine dermatitis and nephropathy syndrome (PDNS)-like clinical signs, reproductive failure, cardiac pathologies, and multisystemic inflammation in piglets and sows. Many aspects of PCV3 infection biology and pathogenesis, however, remain unknown. Here, we used a PCV3 virus stock from the rescue of an infectious PCV3 DNA clone to intranasally inoculate 4- and 8-week-old specific-pathogen-free piglets for evaluation of PCV3 pathogenesis. For 4-week-old piglets, typical clinical signs resembling those of PDNS-like disease were observed when piglets were inoculated with PCV3 alone or PCV3 combined with immunostimulation by keyhole limpet hemocyanin, with a mortality of 40% (2/5) for both types of inoculated piglets during a 28-day observation period postinoculation. Both types of inoculated piglets showed similar progressive increases in viral loads in the sera and had seroconverted to PCV3 capsid antibody after inoculation. Pathological lesions and PCV3-specific antigen were detected in various tissues and organs, including the lung, heart, kidney, lymph nodes, spleen, liver, and small intestine, in both types of inoculated piglets. The levels of proinflammatory cytokines and chemokines, including interleukin 1 beta (IL-1ß), IL-6, IL-23α, gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and chemokine ligand 5 (CCL5), were significantly upregulated in both groups of inoculated piglets. Eight-week-old piglets also exhibited a similar PDNS-like disease but without death after PCV3 inoculation, as evidenced by pathological lesions and PCV3 antigen in various tissues and organs. These results show for the first time successful reproduction of PDNS-like disease by PCV3 infection and further provide significant information regarding the pathogenesis of PCV3 in piglets.IMPORTANCE Porcine circovirus type 3 (PCV3), an emerging porcine circovirus, is considered the cause of porcine dermatitis and nephropathy syndrome (PDNS)-like clinical signs and other systemic diseases in piglets and sows. To evaluate the pathogenesis of PCV3 infection in vivo, we used a PCV3 virus stock from the rescue of an infectious PCV3 DNA clone to intranasally inoculate 4- and 8-week-old specific-pathogen-free piglets and demonstrated successful reproduction of PDNS-like disease in animals that were inoculated with PCV3 alone or PCV3 combined with immunostimulation by keyhole limpet hemocyanin. Both 4- and 8-week-old PCV3-inoculated piglets showed similar increases in viral loads in the sera and had seroconverted to PCV3 capsid antibody. Pathological lesions and PCV3-specific antigen were detected in various tissues and organs, while numerous proinflammatory cytokines and chemokines in the sera were significantly upregulated after PCV3 inoculation. These results will provide significant information regarding the pathogenesis of PCV3 in piglets.