The mites of the family Pyemotidae Berlese (1897) are a large family of ectoparasitoids arthropods, known as pathogen for humans since the 18th century and responsible for the so-called "straw itch" or "grain itch" in granary and dock workers. The identified species of the genus Pyemotes are divided into two groups: the scolyti group (P. scolyti, P. parviscolyti and P. dimorphus) and the ventricosus group (P. tritici and P. ventricosus). The first group is characterized by nonvenomous mites usually parasitizing bark beetles; the ventricosus group includes species associated with a large number of hosts (Coleoptera, Lepidoptera, Hymenoptera, Diptera and Rhynchota), parasitizing all host stages, often highly poisonous and responsible for itchy skin lesions for humans. Several species of Pyemotes mites can be pathogenic to humans, especially in spring and summer and in indoor environments, where worm-eaten wood or infested foodstuffs are present. The most frequent clinical feature is the "strophulus," characterized by small erythematous, edematous, and papular lesions centered by a tiny vescicle evolving into a small erosion covered by crust, or by a central hemorrhagic punctum. Other less frequently observed clinical features are urticaria-like lesions, erythematous excoriated papular and pustular lesions, and rarely scabies-like eruptions. The parasitological diagnosis together with the environmental disinfestation and removing of each substrate infested by insects parasitized by Pyemotidae is mandatory to definitely solve Pyemotes dermatitis.

Buffalo flies (Haematobia irritans exigua) are hematophagous ectoparasites of cattle causing production and welfare impacts in northern Australian herds. Skin lesions associated with buffalo fly infestation and Stephanofilaria nematode infection are manifested as focal dermatitis or ulcerated areas, most commonly on the medial canthus of the eye, along the lateral and ventral neck, and on the abdomen of cattle. For closely related horn flies (Haematobia irritans irritans), Staphylococcus aureus has been suggested as a contributing factor in the development of lesions. To investigate the potential role of bacterial infection in the pathogenesis of buffalo fly lesions, swabs were taken from lesions and normal skin, and bacteria were also isolated from surface washings of buffalo flies and surface-sterilized homogenized flies. Bacterial identification was conducted by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and strain typing by repetitive sequence-based PCR (rep-PCR) and DNA sequencing to determine species similarity and virulence factors. Of 50 bacterial isolates collected from lesions, 38 were identified as Staphylococcus agnetis and 12 as Staphylococcus hyicus, whereas four isolates from normal skin were S. hyicus and one was Mammaliicoccus sciuri. Of the Staphylococcus isolates isolated from buffalo flies, five were identified as S. agnetis and three as S. hyicus. Fifty percent of the buffalo fly isolates had rep-PCR genotypic patterns identical to those of the lesion isolates. Genome sequencing of 16 S. agnetis and four S. hyicus isolates revealed closely similar virulence factor profiles, with all isolates possessing exfoliative toxin A and C genes. The findings from this study suggest the involvement of S. agnetis and S. hyicus in buffalo fly lesion pathogenesis. This should be taken into account in the development of effective treatment and control strategies for lesions. IMPORTANCE Skin lesions in cattle associated with feeding by Haematobia fly species are a significant welfare issue in Australia, North and South America, and Europe. The development of these lesions has been attributed to a number of causal factors, but the exact etiology and pathogenesis were unclear. This study characterized Staphylococcus agnetis and Staphylococcus hyicus strains from cattle skin lesions and in vector flies and demonstrated their role in the pathogenesis of these lesions. These findings will aid the development of targeted and more effective treatment and control strategies for lesions associated with fly infestation in cattle.

Demodex canis is an important parasitic mite causing skin lesions in dogs. However, molecular studies on this species are limited because of the lack of transcriptomic data. To obtain functional genes of D. canis, mites were collected and RNA was extracted for transcriptome sequencing and functional annotation. Coding sequences (CDSs) of important functional genes were screened and identified using bioinformatics strategies. Six complete CDSs were amplified by specific primers, cloned and sequenced. Results demonstrated that the quantity of the RNA extracted from 100 mites was 12.8 ng and the RNA integrity number was 5.4, indicating that it could be used to construct a cDNA library. Transcriptome sequencing yielded 263,619 unigenes, of which 151,048 (57.3%) were functionally annotated. Using bioinformatics strategies, 58 total CDSs were identified as homologous to those of closely related mite species, including 16 types of allergen genes, 13 types of protease genes, and nine types of motion-related genes. The verified CDSs were almost identical to the CDSs of unigenes. Phylogenetic analyses of tropomyosin further revealed that the verified CDSs clustered successively with those of Demodex species and Tetranychus species in Raphignathae, which agreed with the morphological classification, demonstrating the reliability of the transcriptomic data. In conclusion, this study is the first to successfully sequence transcriptome of D. canis, perform functional annotation, and verify CDSs, which will provide ample data for further studies on the functional genes and molecular pathogenic mechanism of D. canis.

The saturniid genus Hylesia is well known for the cutaneous lepidopterism induced by airborne setae on contact with the skin. Although several cases of such dermatitis have been reported in Argentina, no information about their venoms and toxicological implications on human health is available yet. Thus, we conducted a morphological analysis of the setae/spines and a toxinological characterization (through biological assays and proteomic techniques) of the bristle extract from caterpillars and moths of Hylesia sp. from Misiones, Argentina. By scanning electron microscopy, we revealed the various and distinctive types of urticating structures: harpoon-shaped or spiny setae in caterpillars, and setae with barb-like structures in female moths. Their venom electrophoretic profiles were substantially different, presenting proteins related to toxicity, such as serpins and serine peptidases. The female moth venom exhibited higher caseinolytic activity than the caterpillar venom, and coincidentally only the former noticeably hydrolyzed fibrinogen and gelatin. In addition, the female venom displayed a dose-dependent procoagulant effect. The injection of this venom into mouse skin led to the rapid detection of an increased number of intact and degranulated mast cells in the dermis; a few areas of focal subcutaneous hemorrhage were also observed after 5 h of injection. Altogether, this study provides relevant information about the pathophysiological mechanisms whereby Hylesia sp. from northeastern Argentina can induce toxicity on human beings, and paves the way for treatment strategies of accidents caused by this saturniid lepidopteran.

Lutzomyia longipalpis is the natural vector of Leishmania (Leishmania) infantum, but it is also permissive for several Leishmania species that are related to cutaneous leishmaniasis (CL). Maranhao State (Northeast of Brazil) is endemic for CL and has the highest number of cases of diffuse cutaneous leishmaniasis (DCL) in the country. It is a rare disease associated with a defective immune response mainly caused by L. (L.) amazonensis. Additionally, the number of immunosuppressed patients infected with the etiologic agents of CL has increased, including regions in which the main vectors of CL are rare. Therefore, we investigated whether Lu. longipalpis is able to transmit L. (L.) amazonensis to uninfected and immunosuppressed mice, resulting in CL. For that, 291 sand flies took an initial blood meal in mice infected with L. (L.) amazonensis. Of these, 17 underwent a second feeding on uninfected and immunosuppressed mice (of which 58.8% were also positive for Leishmania according to data on the dissection of the intestine). After 27 days of infection, these mice exhibited leishmaniotic lesions. The occurrence of parasites on the animal's skin was confirmed by limiting dilution and immunohistopathological analyses. Parasite DNA was also detected in paw lesions and inguinal lymph nodes. DNA sequencing confirmed the Leishmania species in insects and mice. The results confirmed the ability of Lu. longipalpis to become infected and experimentally transmit L. (L.) amazonensis to immunosuppressed rodents, resulting in leishmaniotic lesions. Our data open perspectives for the potential role of Lu. longipalpis in the epidemiology of urban cutaneous leishmaniasis, especially in immunosuppressed patients.

We present a 5-year-old girl who accidentally crushed an insect of the coleoptera family walking barefoot and secondarily developed an exogenous acral pigmentation. The lesions resolved spontaneously within a few weeks. Proper identification of the insect and a detailed physical examination were key to avoiding unnecessary invasive diagnostic tests.

Tegumentary leishmaniasis (TL) is caused by parasites of the genus Leishmania and transmitted by the sandfly species, insects belonging to the order Diptera, family Psychodidae. Historically, the most endemic area of TL in Argentina has been the northern region. The aim of this work was to analyze the presence and temporal variation of TL cases reported between 1985 and 2019 in Colonia Santa Rosa locality, northern Argentina. Furthermore, its clinical forms were characterized and sandflies were captured. Patients were diagnosed by smear and the Montenegro skin test. For sampling, CDC light traps were placed at 14 sites from 7pm to 7am. The correlation between vegetation cover and sandfly abundance was also studied. One hundred and twenty TL cases were diagnosed and the overall prevalence was 0.75% (≈16 000 inhabitants). Patients presented simple and multiple cutaneous leishmaniasis (88.79%) and the mucocutaneous form (10.83%). Skin lesions were more frequent on the lower extremities (46.73%). Of the total number of sandflies, Nyssomyia neivai (95%) was the predominant species followed by Migonemyia migonei (1.9%), cortelezzii complex (1.3%) and Evandromyia sallesi (0.09%). The persistent occurrence of cases and the presence of sandflies in the locality suggest the existence of endemic transmission in the area. This highlights the need to design prevention and control measures for TL in northern Argentina.

Atopic dermatitis is a chronic inflammatory skin disease, of which incidence is closely related to exposure to environmental pollutants and allergens. Thymic stromal lymphopoietin (TSLP) plays an important role in the early stages of atopic dermatitis development by inducing Th2 immune responses. In addition, TSLP regulates activation of group 2 innate lymphoid cells (ILC2), promoting the pathogenesis of atopic dermatitis. The aim of this study was to investigate whether celastrol alleviated atopic dermatitis symptoms by regulating TSLP expression and ILC2 stimulation. Celastrol suppressed TSLP production in mouse keratinocyte cells by inhibiting NF-ĸB activation. Topical application of celastrol significantly improved atopic dermatitis symptoms induced by house dust mite (HDM) in NC/Nga mice as determined by dermatitis score and histological assessment. Celastrol decreased the levels of TSLP in atopic dermatitis skin lesions of HDM-stimulated NC/Nga mice. Celastrol reduced levels of Th2 cytokines including IL-4, IL-5, and IL-13 in atopic dermatitis skin lesions of NC/Nga mice. Further, celastrol significantly reduced ILC2 population in atopic dermatitis skin lesions of NC/Nga mice. These results indicate that topical application of celastrol improved atopic dermatitis symptoms by lowering TSLP levels and concomitant immune responses. Data demonstrated that reduced TSLP levels and associated lower number of ILC2 cells alleviate atopic dermatitis symptoms induced by house dust mite.

Cera Flava (CF), a natural extract obtained from beehives, is widely used in dermatological products owing to its wound healing, wrinkle reduction, UV-protective, and skin cell turnover stimulation effects. However, its effect on AD-like skin lesions is unknown. In this study, we used a mouse model of AD to evaluate the effects of CP at the molecular and phenotypic levels. Topical house dust mite (HDM) sensitization and challenge were performed on the dorsal skin of NC/Nga mice to induce AD-like cutaneous lesions, phenotypes, and immunologic responses. The topical application of CF for 6 weeks relieved HDM-induced AD-like phenotypes, as quantified by the dermatitis severity score, scratching frequency, and skin moisture. CP decreased immunoglobulin E, histamine, and thymic stromal lymphopoietin levels. Histopathological analysis showed that CF decreased epidermal thickening and the number of mast cells. CF attenuated HDM-induced changes in the expression of skin barrier-related proteins. Furthermore, CF decreased the mRNA levels of inflammatory factors, including interleukin (IL)-1β, IL-4, IL-13, IL-8, TARC, MDC, and RANTES, in dorsal skin tissue via the TLR2/MyD88/TRAF6/ERK pathway. CF influences skin barrier function and immune regulation to alleviate AD symptoms. It may therefore be an effective alternative to topical steroids for the treatment of AD.

Purpose: Lyme borreliosis (LB) occurs throughout Europe. No clinical and seroprevalence studies for LB in Kosovo have been publicly available thus far. Therefore, this study aimed to investigate LB from a tick bite perspective in the Pristina region, Kosovo. Methods: This single-center prospective observational study enrolled consecutive adult participants (≥18 years of age) with tick bite (embedded tick in the skin), who were examined at the Clinic of Infectious Diseases, Pristina, between January 2015 and August 2018. At the first visit related to the index tick bite, ticks (the complete ticks or parts of the ticks) were removed from the skin, blood samples were taken for serological tests, and antibiotic treatment was started when deemed necessary. The complete, undamaged ticks removed were proceeded for entomological identification. Participants were followed up at 2 months (serological tests were repeated) and 6 months after the index event for the development of clinical manifestations of LB and/or seroconversion against Borrelia burgdorferi. Results: A total of 380 subjects were included in the study. Most cases were seen in May and June in all study years. All 117 preserved ticks were identified as Ixodes ricinus. Immunoglobulin G seroprevalence among subjects during the first visit in the study was 28/380 (7.4%). Erythema migrans (EM) was clinically diagnosed in 74/380 patients (19.5%, 95% confidence interval 15.6-23.8). Only 15 clinically diagnosed EM (in seronegative patients) were serologically confirmed with seroconversion (2 months later), 3.9% of all subjects included in the study. There were three cases with clinical manifestation between the second and third visit: EM recidivans, multiple erythema, or several nonspecific systemic symptoms. Doxycycline and amoxicillin were mainly used for the treatment of borrelial skin lesions. Conclusion: This assessment can help indicate the need for disease awareness and reinforce the importance of primary prevention measures, early diagnosis, and appropriate treatment.

Atopic dermatitis (AD) is a multifactorial inflammatory skin disease of complex etiology. Despite its increasing prevalence, treatment for AD is still limited. Crude drugs, including herbal extracts or natural resources, are being used to treat AD symptoms, with minimum side effects. Cicadidae Periostracum (CP), derived from the slough of insects belonging to the family Cicadidae, is a commonly used crude drug in traditional Asian medicine to treat/control epilepsy, shock, and edema. However, the effect of CP on AD-like skin lesions is unknown. In this study, we examined the effect of a CP water extract on AD disease development in vivo, using a house dust mite-induced AD mouse model, and in vitro, using HaCaT keratinocytes and a 3D human skin equivalent system. Importantly, CP administration alleviated house dust mite-induced AD-like symptoms, suggested by the quantified dermatitis scores, animal scratching behaviors, skin moisture retention capacity, and skin lesion and ear thickness. Furthermore, histopathological analysis demonstrated that CP decreased intralesional mast cell infiltration. In addition, CP treatments decreased the systemic levels of immunoglobulin E, histamine, and thymic stromal lymphopoietin (TSLP) and the local mRNA expression of TSLP and several Th1/Th2 cytokines. Our data suggest that these effects were mediated by the inhibition of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation. In vivo and in vitro CP treatments resulted in the downregulation of inflammasome components, such as ASC and cleaved caspase-1, as well as related mediators such as IL-1β and reactive oxygen species. Collectively, our results suggest that CP is a potential therapeutic agent for AD, controlling inflammatory responses through the suppression of NLRP3 inflammasome activation.

Ornithonyssus bursa (Berlese, 1888), also known as the tropical fowl mite, is a blood-feeding ectoparasite of domestic and wild birds. It is considered a serious pest to poultry in warm and tropical climates and has been reported to attack humans, causing gamasoidosis. Avian-mite dermatitis may be difficult to recognize and misdiagnosed as bites from other arthropods. The present report describes two cases of human dermatitis linked to O. bursa infestation. Both cases occurred in an apartment in a residential area in Oeiras, Portugal, where two members of the same family presented with pruritic erythematous skin eruptions disseminated over their body over a period of 4 months. The lesions were located mostly in the pelvic, gluteal, coccygeal, and perineal regions, and also on the neck, wrists and torso. On inspecting the mattresses and the covers of the bedrooms, three mites ~1 mm long by 0.5 mm wide were found. The three specimens were identified as O. bursa. Investigations tracing back the source of infestation, revealed that the mites were carried over from chickens raised 45 km away (Sesimbra, Setúbal) that, after being slaughtered for consumption, had been transported by car to the apartment in Oeiras. The chickens were farmed in an open backyard henhouse that allowed free access to several species of wild birds, including pigeons (Columba livia), turtle doves (Streptopelia decaocto), and sparrows (Passer domesticus). Recent reports suggest that O. bursa may be established in Mediterranean countries, increasing the risk of gamasoidosis. This is the first record linking O. bursa infestation of chickens with human dermatitis in continental Portugal. More research is needed to assess the extent of poultry infestation and evaluate the possible implications for the poultry industry, as well as for human health in Portugal.

Spider angioma is a benign vascular lesion reminiscent of a spider's body characterized by peculiar dilatation of end vasculature. The lesion is characterized by a central spot and extensions which radiate outward like a spider's body. Spider angiomas may appear as a solitary or multiple lesion that arises on the skin surface of the face, neck, chest, and arms; these lesions have been rarely observed in the sublingual mucosa and in the gut, and to date, they have never been reported in the nasal mucosa. In this article, we report a spider angioma of the nasal cavity found as an occasional finding during a narrow band imaging nasopharyngeal endoscopy in a 70-year-old male patient with hepatitis C virus-related liver cirrhosis and a history of total laryngectomy in 2013 due to laryngeal squamous cell carcinoma. The lesion was located in the mucosa of the pavement of the posterior portion of the left nostril; it was painless and asymptomatic.

The Atlantic bluefin tuna (ABFT; Thunnus thynnus) today represents one of the economically most important species for Croatian fisheries industry. Although the most diverse and abundant parasitofauna is usually found in the largest specimens of wild ABFT, the opposite was observed in captivity where parasite populations significantly decline by the end of the farming cycle. Copepod Brachiella thynni, is a skin parasite frequently parasitizing tuna, whose population also decreases in number throughout the rearing process. In order to better understand the immunity mechanisms underlying ABFT reaction to B. thynni infection, we studied expression profiles of immunity related genes; interleukin 1β (il1β), tumour necrosis factors (tnfα1, tnfα2), complement component 4 (c4) and caspase 3 (casp3), in peripheral blood leukocytes (PBLs) during in vitro stimulation by B. thynni protein extracts (i.e. antigens) and in infected tissues at B. thynni parasitation site. Finally, a histopathological analysis of semi-thin and ultra-thin sections of tissues surrounding B. thynii attachment site was performed to evaluate the severity of parasite-induced lesions and identify involved cell lineages. In vitro stimulation of ABFT PBLs with B. thynii antigens caused a dose-depended upregulation of selected genes, among which tnfα1 showed the highest induction by both concentrations of B. thynni protein extract. However, targeted genes were not significantly upregulated in the infected tissue. Also, no significant alterations in ultrastructure of epithelial layers surrounding B. thynii attachment site were noticed, except local tissue erosion, necrosis of squamous epithelium and proliferation of rodlet and goblet cells. Our results suggest that B. thynii has evolved strategies to successfully bypass both innate immune response and the connective-tissue proliferation processes. Therefore, the observed disappearance of this copepod by the end of the rearing process is more likely related to its limited lifespan on the host and its inability to complete the life cycle in the rearing cages, rather than host's reaction.

Acral purpura is generally a hallmark for severe internal disease. However, exogenous pigmentation related to contact with invertebrates, can induce acral purpura-like lesions. Data regarding the beetle's ability to cause skin hyperpigmentation or purpura-like lesions are scarce. We report a case of exogenous pigmentation caused by accidental contact with a darkling beetle, clinically simulating acral purpuric lesions. The history of recent drug inhalation and abnormal autoimmunity tests made this diagnosis difficult.

In November 2019 a 5-month-old mixed-breed rabbit presented to Chungbuk National University Veterinary Teaching Hospital, Cheongju-si, Chungbuk, Republic of Korea (Korea) with symptoms comprising pruritus, crusts on skin, poor appetite and reduced defecation. The rabbit was purchased 2 months prior from a pet shop located in a big market, and that the symptoms were first observed about 2 weeks prior to the hospital visit. Physical examination revealed that the patient had crust formation and alopecia on the nose together with lesions on the digits. A skin scraping test was performed using mineral oil and a high density of mites was observed by microscopy. Each mite showed a round, tortoise-like body with 4 comparatively short pairs of legs. The anus was located at the terminal unlike with suspected pathogen, Notoedres cati. Based on morphological characteristics, we identified the mite as Sarcoptes sp. Ivermectin was administered weekly by subcutaneous injection at a dosage of 0.4 mg/kg, and 4 weeks of follow-up study revealed the patient was fully recovered. And no more mites were detected from the case. This is the first case report of sarcoptic mange in a pet rabbit in Korea.

The marine crustacean Lepeophtheirus salmonis (salmon louse) is a common ectoparasite of wild and farmed salmonids. The parasite has a complex ontogeny comprising eight instars. The planktonic copepodid stage settles on host skin and pass through five instars to reach the adult stage. The present study comprises an experimental infestation of Oncorhynchus mykiss (rainbow trout) with salmon lice and describes histopathology and host immune responses in skin beneath the louse at multiple time points encompassing all louse developmental stages. Each fish was exposed to 80 infective copepodids, a mean no. of 32 parasites reached the preadult I stage whereas a mean no. of 11 parasites reached the adult stage. A progression in the severity of cutaneous lesions was observed, and levels of immune gene transcripts at the attachment site revealed a dynamic response, initially related to innate immunity. Later, immune cells accumulated in the dermis concomitant with a moderate decrease in levels of transcripts characteristic of both innate and adaptive immune responses. The present study also demonstrates that the cutaneous immune response was mainly induced at lice affected sites, while non-affected skin resembled the skin of untreated control. This indicates that the skin cannot be regarded as a uniform organ and requires careful sampling at all salmon louse stages.

Myiasis is a common travel-associated dermatosis. We describe a 52-year-old Italian man who acquired Dermatobia hominis when bitten by a mosquito during a visit to Argentina. He had a painful nodular lesion on the left cheek that had been present for about 3 weeks. The complete removal of the larva is the goal of medical treatment. Prescription of antibiotics to avoid secondary infections is not recommended. For psychological reasons and due to the failure of previous therapies, the lesion was excised. Travelers to endemic areas should be informed of preventive measures to reduce mosquito bites and transmission of the infestation.

Trombiculids parasitize a wide variety of terrestrial vertebrates, including domestic animals, throughout the world. They are parasites only during their larval stages, causing several dermatological lesions on their hosts, such as acute dermatitis, erythema, excoriation, erosion, papules, crusts and alopecia on the ear margins, face, interdigital spaces and abdomen. Neotrombicula is one of the several genera in Trombiculidae family, which cause trombiculosis. The most common species implicated in clinical cases is Neotrombicula autumnalis. However, several reports have shown that Neotrombicula inopinata (Oudemans, 1909) can also play a role in trombiculosis. Here, we describe the first case of N. inopinata infestation in domestic cats from mainland Portugal. Since nucleic acids of Anaplasma phagocytophilum and Borrelia burgdorferi have been found in Neotrombicula autumnalis and Rickettsia spp. in Neotrombicula inopinata, a correct taxonomical identification is essential to understand the role of these mite species as possible vectors of pathogens.

Bedbugs, mites, and scabies are ectoparasites that commonly affect humans. Bedbugs (Cimex species) were once rare in the United States but are now common. They cause intensely pruritic lesions on areas of exposed skin. The bites are highly allergenic and can cause asthma exacerbations or anaphylaxis. Management of bedbug bites involves symptomatic relief of itching and dealing with patient anxiety. Identification and elimination of infestation are most important. Another ectoparasite of concern is lice (Pediculus and Pthirus species), which causes head, body, and pubic infestations. Patients can experience hypersensitivity to the saliva of lice, but such symptoms often do not develop until several weeks after infestation. Diagnosis involves identification of nits (ie, eggs) or lice on the skin or hair. Several pediculicides are used for management but wet combing without use of pediculicides may be more effective. A third common ectoparasitic infestation, scabies (ie, infestation with the mite Sarcoptes scabiei), affects 5% of the world's population. Patients present with pruritic lesions in skin folds, finger webs, and areas in which clothing is tight. The diagnosis can be confirmed with dermatoscopy or microscopy. Management involves use of permethrin cream, oral ivermectin, or benzyl benzoate.