Tick exposures and alpha-gal syndrome: A systematic review of the evidence.

Alpha-gal syndrome (AGS) refers to a delayed allergic reaction to galactose-α-1,3-galactose (α-Gal) that occurs following the consumption of mammalian meat or exposure to other animal-based foods and products. Increasing evidence suggests that bites from certain tick species can lead to AGS through sensitization of a person's α-Gal specific IgE levels. This systematic review aimed to summarize the published evidence on this topic to understand post-tick exposure AGS epidemiology and health outcomes. A structured search for literature in eight bibliographic databases was conducted in January, 2020. Grey literature and verification searches were also performed. The exposure of interest was tick bites, and the outcome of interest was AGS. All primary research study designs were eligible for inclusion. References were screened for relevance, and data extraction and risk-of-bias assessment were conducted on relevant studies by two independent reviewers. Data were descriptively and narratively summarized. Of 1390 references screened, 102 relevant articles (103 unique studies) were identified (published from 2009 to 2020). Most studies (76.7 %) were case report or series. These 79 studies reported on 236 post-tick exposure AGS cases from 20 different countries, mostly the United States (33.5 %), Spain (19.5 %), Sweden (18.6 %), and France (12.7 %). The mean case age was 51.3 (SD = 16.7, range 5-85, n = 229), while 68.1 % were male (n = 226). The most commonly reported symptom was urticaria (71.2 %); 51.7 % of cases reported anaphylaxis. Twenty-one observational studies were reported, mostly (95.2 %) among clinical allergy patients. The proportion of AGS cases that recalled tick bites was highly variable across these studies. Three challenge studies evaluating tick exposures and α-Gal levels in α-Gal deficient mice were identified. The existing evidence suggests tick bites lead to α-Gal-specific IgE sensitization, which can cause AGS, but further research is needed to clarify if AGS is only attributable to certain tick species and whether other vectors may trigger AGS. Additional research is needed on risk factors for AGS development, evaluation of diagnostic immunoassays, and the epidemiology and distribution of AGS in different populations. Climate change will likely lead to future cases of AGS in new regions worldwide due to the predicted alteration of suitable tick habitats.

Urticaria and silent parasitism by Ascaridoidea: Component-resolved diagnosis reinforces the significance of this association.

Urticaria remains a major problem in terms of aetiology, investigation, and management, and although parasitic diseases are considered potential causes, the absence of a consistent link between parasitic infections and skin allergy symptoms leads to the need for a deeper study of parameters that support this association. The objectives of this study were to analyse a possible relationship between parasitism by Ascarididae (Toxocara canis and Anisakis simplex) and the clinical expression of urticaria and to identify possible parasitic molecular markers for improving the diagnosis of unknown urticaria aetiology. The prevalence of Toxocara and Anisakis infestations was evaluated by measuring the levels of specific IgG (sIgG) and IgE (sIgE) antibodies against crude extracts and isolated components from whole larvae of Anisakis simplex (Ani s 1, Ani s 3 and Ani s 7) and Toxocara canis (TES-120, TES-70, TES-32 and TES-26) using immunologic and molecular diagnostic methods. A cross-sectional study was performed in a group of 400 individuals. The study group consisted of 95 patients diagnosed with urticaria (55 with chronic urticaria and 40 with acute urticaria). A control group consisted of 305 subjects without urticaria (182 diagnosed with respiratory allergy and 123 without allergy). Statistically significant differences were demonstrated in the seroprevalence of specific IgG and IgE antibodies between the urticaria patients and the healthy general population when isolated ascarid antigens were evaluated. The prevalence of IgG antibodies against Ani s 1, IgE antibodies against TES-120 and IgE antibodies against TES-70 were significantly different between the control individuals (healthy general population) and patients with urticaria. Moreover, the urticaria patient group demonstrated a higher seroprevalence of antibodies (sIgE and sIgG) against Anisakis simplex larva whole extract than the control group but just with statistically diferences when sIgE was evaluated. The presence of IgE and/or IgG antibodies against Ani s 3 (tropomyosin) can help to discriminate between patients with and without urticaria. Both ascarids seem to be associated with urticaria, although in our region, Anisakis seems to have greater involvement than Toxocara in this relationship. Molecular diagnostics can be used to associate urticaria with parasite infestations. Tropomyosin and Ani s 1 were the most relevant markers to demonstrate the association between urticaria and the most relevant Ascarididae parasites in our region.

Traumatic rupture of a hydatid cyst of the liver presenting with skin lesions.

The hydatid cyst is the evolution of a parasitic infection caused by Echinococcus granulosus and is an endemic disease in Turkey. The hydatid cysts of the liver can give origin to several complications and the rupture is one of them. Rupture can occur spontaneously or as a result of external trauma. The presentation with skin lesions is very rare. We present a 20-year-old male patient who presented himself after a car accident, and was diagnosed with a rupture of traumatic hydatid cysts due to hives rash. In the operation, a scolicidal gent was administered to the cyst, the cyst wall was partially excised and the germinative membranes were removed. Medical treatment with albendazole was started. The postoperative period was quiet. The intraperitoneal traumatic rupture of a hydatid cyst is rare, but it can cause severe anaphylactic reactions and biliary peritonitis. Although a rare and broken hydatid cyst due to trauma may present with skin lesions in a patient in an endemic region, it should be considered in the differential diagnosis. KEY WORDS: Primary hydatid cyst, Trauma, Urticaria.

Blastocystis, urticaria, and skin disorders: review of the current evidences.

Blastocystis is one of the most common intestinal protozoan parasites worldwide, which is linked to cutaneous lesions and urticaria. In a setting of systematic review, the data on the association of Blastocystis infection with cutaneous lesions were searched in order to summarize the main clinical symptoms, diagnostic methods, treatment, and outcome of the patients. The search identified 28 eligible articles, including 12 cross-sectional studies and 16 case reports/case series (including 23 cases). A diverse spectrum of skin symptoms, mainly urticaria, rash, and itching, was reported from the studies. Of the 23 infected cases with the skin symptoms, gastrointestinal symptoms were reported from the 16 cases, whereas 7 cases with urticaria had asymptomatic infection. The most frequent subtypes were ST1, ST2, and ST3, respectively. Metronidazole, paromomycin, and tinidazole were the most prescribed drugs in patients with single Blastocystis infection. Notably, urticaria and other cutaneous symptoms of all treated patients were resolved after treatment. In conclusion, this study indicates that Blastocystis infection can be a neglected cause of urticaria and skin disorders. Since the treatment of Blastocystis infection is simple, screening and treatment of this infection should be considered in patients with urticaria and other skin disorders.

Morbidity Associated with Chronic Strongyloides stercoralis Infection: A Systematic Review and Meta-Analysis.

Strongyloides stercoralis, a worldwide-distributed soil-transmitted helminth, causes chronic infection which may be life threatening. Limitations of diagnostic tests and nonspecificity of symptoms have hampered the estimation of the global morbidity due to strongyloidiasis. This work aimed at assessing S. stercoralis-associated morbidity through a systematic review and meta-analysis of the available literature. MEDLINE, Embase, CENTRAL, LILACS, and trial registries (WHO portal) were searched. The study quality was assessed using the Newcastle-Ottawa scale. Odds ratios (ORs) of the association between symptoms and infection status and frequency of infection-associated symptoms were calculated. Six articles from five countries, including 6,014 individuals, were included in the meta-analysis-three were of low quality, one of high quality, and two of very high quality. Abdominal pain (OR 1.74 [CI 1.07-2.94]), diarrhea (OR 1.66 [CI 1.09-2.55]), and urticaria (OR 1.73 [CI 1.22-2.44]) were associated with infection. In 17 eligible studies, these symptoms were reported by a large proportion of the individuals with strongyloidiasis-abdominal pain by 53.1% individuals, diarrhea by 41.6%, and urticaria by 27.8%. After removing the low-quality studies, urticaria remained the only symptom significantly associated with S. stercoralis infection (OR 1.42 [CI 1.24-1.61]). Limitations of evidence included the low number and quality of studies. Our findings especially highlight the appalling knowledge gap about clinical manifestations of this common yet neglected soil-transmitted helminthiasis. Further studies focusing on morbidity and risk factors for dissemination and mortality due to strongyloidiasis are absolutely needed to quantify the burden of S. stercoralis infection and inform public health policies.

Atypical Presentation of Human Acute Muscular Sarcocystosis: Sarcocystis Nesbitti Confirmed on Molecular Testing.

BACKGROUND Acute muscular sarcocystosis (AMS) is one of a spectrum of diseases caused by the Sarcocystis parasite which infects humans in regions where it is endemic. Infections present with non-specific signs and symptoms and have been known to occur in clusters. CASE REPORT A 51-year-old Vietnamese male presented to Tan Tock Seng Hospital, Singapore with 3 weeks of fever, urticarial rash, non-productive cough, and lower back pain. He had an extensive travel history prior to presentation. Magnetic resonance imaging (MRI) showed myositis involving the paravertebral and upper thigh muscles. The infection was confirmed on open muscle biopsy and Sarcocystis nesbitti was identified on molecular testing. The patient was treated with prednisone and methotrexate. CONCLUSIONS AMS must be considered in a patient with history of exposure to an endemic area. Diagnosis of the condition and identification of S. nesbitti as the causative organism will help to further study of this particular condition and guide treatment.

Chronic strongyloidiasis with recurrent asthma exacerbations and steroid-associated 'hives'.

A 74-year-old man experienced worsening asthma for several years. Oral steroids were required on multiple occasions for asthma treatment. During his steroid courses, he developed a hive-like rash, which would resolve after completion of each steroid course. He was from Romania, and had lived in the USA for many years. Laboratory testing had shown eosinophilia. He was eventually diagnosed with strongyloidiasis by serology. Treatment with ivermectin led to marked improvement but not resolution of his long-term asthma. His hive-like rash, which was likely larva currens, did not recur with a subsequent steroid course. Improved recognition of strongyloidiasis, particularly in steroid-treated patients, is needed.

The Prevalance of Blastocystosis among Patients with Gastrointestinal and Dermatologic Complaints and Effects of Blastocystis spp. Density on Symptomatology.

OBJECTIVE: Blastocystosis has been linked with non-specific symptoms, such as diarrhea, abdominal pain, and distention. In this study, we evaluated the relationship between Blastocystis spp. with urticaria and intestinal symptoms. METHODS: The results of the stool examinations of the patients who were referred to Ege University Medical Faculty Hospital's Medical Parasitology Department Direct Diagnosis Laboratory with gastrointestinal (GIS) and/or dermatologic symptoms between January 2011 and July 2016 were retrospectively scanned. RESULTS: Of the evaluated 37108 stool samples, 2573 (6.93 %) were identified to be positive for Blastocystis spp. The patients with gastrointestinal complaints comprised 68.4% of Blastocystis spp. positive samples (1.761 samples) while 30.1% of patients had dermatologic symptoms (urticaria) (776 samples). Blastocystis spp. density in the non-amplified (without using any stool concentration technique) stool samples of the patients with GIS and dermatological symptoms was as follows: 2.47%, 1.35% rare, 21.73%, 22.17% few, 49.65%, 54.29% medium, 26.27%, and 22.17% dense, respectively. CONCLUSION: 75.92% and 76.46% of the patients with GIS and dermatological complaints had medium to dense parasite densities in their stool samples respectively. This suggests a positive correlation between parasite density and GIS and dermatologic symptomatology.

Toxocara Canis and Chronic Urticaria.

No Abstract.

Mysterious chronic urticaria caused by Blastocystis spp.?

Species of the genus Blastocystis, which are single-cell, intestinal protozoan parasites of humans and animals, remain mysterious, with unclear clinical and epidemiologic significance. In recent years, many researchers have suggested a possible connection between Blastocystis spp. infection and chronic urticaria. In the present article, we review the literature and discuss the possible associations between the clinical symptomatology and pathogenicity of this organism in terms of its subtypes, morphologic forms, genetic diversity, and interactions with other intestinal microbiota.

Toxocara Canis IgG Seropositivity in Patients with Chronic Urticaria.

We aimed to investigate IgG antibody levels specific to Toxocara canis (T. canis), a parasite which subsists in dog's intestine, on serum samples obtained from patients with chronic urticaria (CU) to evaluate effective risk in CU etiopathogenesis. In this study, 73 patients diagnosed with CU and 109 healthy individuals as control group, were included. Various factors such as sex, age, education and income, daily hand washing habits, history of dog owning and soil eating were questioned in patient anamnesis. T. canis IgG antibodies were detected using an enzyme linked immunosorbent assay (ELISA) kit prepared with T. canis larval excretory-secretory antigens. Positive results were confirmed with western blot (WB) WB test. We found T. canis IgG positivity in 17.8% (n=13) of patients (n=73) with CU. But we did not observe any T. canis IgG positivity in healthy controls (n=109). Low molecular weight bands (24-35 kDa) were observed in 11 samples in WB analyses while two of the samples were weakly positive. It is revealed that dog owning history increases T. canis seropositivity 12.9 times while insufficient daily hand washing habit (less than six times a day) increases seropositivity 20.7 times. Our study showed that T. canis may trigger CU since we found 17.8% seropositivity in 73 patients with CU and none in 109 healthy individuals. Moreover, various socio-demographic characteristics have been shown to affect T. canis seropositivity in patients with CU.

Blastocystis and urticaria: Examination of subtypes and morphotypes in an unusual clinical manifestation.

Blastocystis is a human common enteric protist that may colonize a large variety of non-human hosts linked to symptoms and diseases such as abdominal pain, constipation, diarrhea, urticaria, flatulence and irritable bowel syndrome (IBS). Blastocystis exhibits remarkable genetic diversity and multiple subtypes (STs) within the genus with no absolute associations with clinical symptomatology. Here we analyzed fecal samples from Argentinean patients (n=270) belonging to symptomatic (urticaria and non-specific gastrointestinal symptoms, n=39) and asymptomatic control (n=28). Those patients infected with Blastocystis (n=67) were submitted for morphological analysis, DNA extraction, 18S PCR, sequencing and STs identification according to DNA barcoding. Blastocystis vacuolar forms were the predominant morphotype (75%), ameboid-like forms were evidenced in 1.5% of samples. Blastocystis ST3 was detected in 71.6% (n=48), of which 71.4%, (n=35) and 28.6% (n=14) belonged to symptomatic and asymptomatic respectively. Other subtypes identified were ST1 (14.9%), ST6 (7.5%) and ST2 (5.9%). Blastocystis 18S barcoding evidenced in non-urticaria symptomatic patients and asymptomatic control group the presence of allele 134 (ST3) (p<0.0001), while allele 34 (ST3) was detected in 85.7% (18/21) of symptomatic uricaria as compared with control group (1/21) (p<0.0001). The presence of a particular allele (a34) significantly associated with urticaria patients was detected and the clinical implications of these findings are herein discussed.

Recurrent toxocariasis due to chronic urticaria and successful treatment with prolonged albendazole therapy.

Toxocariasis is a worldwide human helminthiasis, especially seen in temperate and tropical climate regions around the world. The diagnosis of this disease is performed on the basis of clinical symptoms and laboratory findings. Albendazole is one of the treatment choices for toxocariasis, with a currently recommended regimen of 10 mg/kg/day in two doses (400 mg twice daily) for 5 days. However, there is no precise consensus about the duration of the treatment. In this article, we report a case of toxocariasis; the patient visited our infectious disease polyclinic with complaints of long-term itching and urticarial skin lesions that were resistant to routine treatment and that recurred. Then, recurrent disease was resolved and skin lesions were diminished after prolonged albendazole therapy.

Positive associations between infections of Toxoplasma gondii and seropositivity with Anisakis simplex in human patients suffering from chronic urticaria.

Toxoplasma gondii is a food-borne and orofecal microorganism which produces chronic infection, and attempts have been made to prove its negative association with atopy in the context of the hygiene hypothesis. Anisakis simplex is a fish parasite associated with chronic urticaria (CU) in endemic regions. We analysed the relationship between both infectious agents in CU. We included 42 patients with chronic urticaria (18 patients with CU associated with A. simplex sensitization and 24 not sensitized CU patients). Patients were assessed for atopy by a skin prick test (SPT) against common aeroallergens and for respiratory symptoms. Anisakis simplex sensitization was assessed by SPT and specific IgE by CAP fluoro-enzyme immunoassay (CAP-FEIA). Anti-T. gondii IgG levels were measured by enzyme-linked immunosorbent assay (ELISA). CU patients were analysed with respect to T. gondii seropositivity, A. simplex sensitization, atopy and immigrant status. The seroprevalence of T. gondii was 40.5% in CU patients and 42.1% in the control group. Immigrants were more frequently infected by T. gondii (41.2% versus 12%; P =0.036). Anti-T. gondii IgG antibodies were associated with past A. simplex parasitism (odds ratio 6.73; P =0.03) and independently with atopic sensitization (odds ratio 5.85; P =0.04). In CU patients, T. gondii has no protective effect on atopic sensitization or A. simplex sensitization.

A rare manifestation of cysticercosis infestation.

There are many causes of urticaria, which may vary from infections to malignancy. Among the infections, infestations by cysticercosis (larval stage of the tapeworm called Taenia solium) is an important cause. The present report is of forty four years old female who presented with urticaria and swelling on face. The swelling was later diagnosed as cysticercosis by noninvasive ultrasonography. The urticaria subsided after the treatment of cysticercosis. We report this case for rarity of its presentation.

Seroprevalence of IgG anti-Toxocara canis antibodies and anti-Fasciola sp. antibodies in patients with urticaria.

AIMS: Chronic urticaria (CU) is defined by recurrent episodes occurring at least twice a week for 6 weeks and generally characterized by the rapid appearance of wheals and/or angioedema and may be associated with parasitic infections. We aimed to investigate the seroprevalance of Toxocara canis and Fasciola species in patients with CU. MATERIALS AND METHODS: We included 55 patients (in age 16-55) with urticaria admitted in study. As a control group we recruited 30 healthy volunteers they had no history of urticaria, rhinitis, asthma, atopic eczema/dermatitis syndrome (AEDS), or other relevant diseases. IgG antibodies to Toxocara canis and Fasciola species were investigated by ELISA method. RESULTS: In a total of 55 patients (mean age: 31.85 ± 8.92), 8 patients (14.5%) were positive for IgG antibodies to Toxocara canis. Among seropositive patients (mean age: 38.62 ± 12.46) 6 patients were female. No patient was positive for Fasciola by ELISA. Six of Toxocara canis seropositive cases were frequently visited or lived in rural areas and had contact with pets. CONCLUSIONS: Patients with urticaria, should be tested for Toxocara canis and treated with anthelminthic drugs in endemics areas for toxocariasis.