Sex: F
Vaccine: COVID19
Symptoms: Ultrasound abdomen, White blood cell count
Clinical narrative: Aden mesenteritis; This is a literature report for the following literature source(s).  Coronavirus disease 2019 (Covid-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2) is considered a global public health crisis in 2020, generating significant morbidity and mortality worldwide. To date, the vaccination of the global population, seems to be the only effective strategy to achieve the 'herd immunity' and consequently prevent the virus circulation.  This requires the entire population to be vaccinated, including children and adolescent, in addition, since the antibody response to SARS-Cov-2 has been shown to wane in both adults and children, more booster doses are needed. Vaccinating children and adolescents is a very debated topic, both because there are contrasting opinions about their role in spread of SARS Cov-2 and also because, since covid-19 in children has a mild or asymptomatic course in most cases, it is important to carefully assess the risk and benefit of vaccination in this age group. The pediatric vaccination could have many advantages, not only in terms of reducing viral transmission and preventing the disease, especially in the elderly or high risk individuals, but also by contributing, associated with the implementation of preventive measures in children to migrating the downstream effects of pandemic, such as social isolation and interruption of education and also to protect from two long term consequences of SARS-COV-2 infection in children (multisystem inflammatory syndrome associated with coronavirus disease 2019-MIS-C and long covid syndrome). Therefore, to justify childhood vaccination, it is necessary for the scientific community to report all possible adverse events related to the vaccine. This could improve community knowledge about vaccination in children, debunk numerous fake news reports and increase the complications and consent of caregivers to vaccination. In the context we report a possible rare complications post SARS-Cov-2 vaccine aden mesenteritis occurred in a 13-year-old girl after the first dose of BNT162B2. Authors describe a case of a 13-year-old girl who presented to the emergency department with a five day fever (maximum temperature 39.5 degree C). Th mother reported that the girl had received the first dose of SARS-Cov-2 vaccine (BNT162B2) less than twelve hours before the onset date of fever. The fever was associated with a headache that was slightly responsive to anti-inflammatory drugs, abdominal pain, one episodes of vomiting per day and two episodes of diarrhea per day. On the advice of the family pediatrician, the child has started antibiotic therapy with amoxicillin + clavulanic acid with little benefit. The mother denied possible contact with positive cases of SARS-Cov-2 or recent travel. After collecting the patient's medical history, the history was remarkable of recurrent headache symptoms. The remaining family and pathogenically history included no other noteworthy items except the dept of the paternal grandfather from Covid-19 in the previous year. Physical examination on admission was unremarkable, except for a temperature of 38 degree C, hyperemia of the pharynx and slight tenderness on palpation of the abdomen, the child's antigenic and molecular swabs for SARS-CoV-2 were negative. Given the persistent symptoms not associated with a significant clinical finding and the possible link with vaccine administration, the patient was admitted and focused assessment of febrile symptoms, headache and gastrointestinal symptoms was performed. Differential Diagnosis: Investigations and treatment: On admission, the patient performed blood examinations that showed an increase in systemic inflammation index (C-reactive protein-CRP 5.21 mg/dl, cutoff of normality greater than 0.5mg/dl) and a slight increase in white blood cells (10.45x10 3/ul) with an increases in the neutrophil quota (neutrophils 84.5%-8.83x 10 3/ul, lymphocytes 10 %-0.54x 10 3/uL, monocytes 10.1%-1.06x10 3/uL). The examination of blood biochemistry and the study of coagulation indices was within the normal range. Additionally, the patient performed the following instrumental examinations: a CT encephalic scan for persistent headaches that was non-responsive to medication, which was negative, a color doppler echocardiography with normal results, and an abdominal ultrasound, which revealed the presence of enlarge lymph nodes and mesenteric inflammation, consistent with a diagnosis of aden mesenteritis. Thus, the patient started fluid the therapy with saline (0.9%) solution at 50 mL/h and an antibiotic therapy with ceftriaxone ev 2g single daily administration. During hospitalization, the patient also performed the following tests: serology for covid-19, which confirmed positively for Covid-19 IgG (32.77 AU/mL, cutoff of normality less than 10) and covid-19 IgM negative (0.92 AU/mL), a stool culture test that was negative for bacteria, parasites, adenovirus and rotavirus (the search for SARS-Cov-2 in stool was not possible in our laboratory), blood cultures that were negative for anaerobic microorganism. Furthermore, to investigate the girl's persistent headache, we performed an ophthalmic counselling with and examination of the fundus oculi that showed a normal result, and a neurological counselling, who recommended a nuclear magnetic resonance (MRI) of the brain district in the election. The patient performed MRI examination with a diagnosis of non-specific gliosis. Outcome and Follow-up: During the hospital stay, the patient's clinical condition improved, with the last fever peck on the second day of admission an normalized of abnormal symptoms in 3 days. Laboratory test shown normalization of the leucocyte count and the return of inflammatory indices to the normal cutoff at discharge. Abdominal ultrasound showed a reduction mesenteric inflammation and lymph node involvement compared to the first examination. Finally, the patient was discharged in good general condition with an indication of ultrasound and neurological follow-up and the administration of probiotics at home for 10 days.  Discussion: Only one year after the outbreak of the pandemic, the collective scientific effort has allowed for the release of effective vaccine against SAR-CoV-2. Different vaccines were authorized for use in adult people, while at pediatric age, RNA-based vaccines are among the most advance candidates. Two vaccines, BNT162B2 (Pfizer-Biontech) and mRNA-1273 (Moderna), have completed experimental, demonstrating safe and effective profiles in children. On 07Dec2021, the authorization of BNT162B2 vaccine was expanded to include children from 5 to 11 years of age. These mRNA vaccines contain nucleoside-modified messenger RNA encoding Spike-protein S, containing the receptor-binding domain that allows for host entry. Few date are available on possible adverse effects of the vaccine in children and adolescents, the current evidence shows that, in children 12-15 years old, local and systemic adverse effects after BNT162B2 vaccines are relatively common, particular after the second dose, most are mild severity and are limited to the first two days after vaccination. The most commonly reported effects are injection site reactions, mainly pain (86% after the first dose, 79% after second dose), swelling and induration of the site (7% after the first dose and 5% after the second dose), redness (6% after first dose and 5% after second dose). Systemic adverse effects are rarer and involve: fatigue (1 degree dose 60%, 2 degree dose 66%), headache (1 degree dose 55%, 2 degree 65%), shiver (1 degree 28%, 2 degree 42%), myalgia (1 degree  24%, 2 degree dose 32%), fever (1 degree 10%, 2 degree 20%), joint pain (1 degree 10%, 2 degree 16%), diarrhea (1 degree  8%, 2 degree dose 6%), and vomiting (1 degree dose 3%, 2 degree 3%). In addition, the mRNA-1273 vaccine showed a good safety and efficacy profile among adolescents. As with the BNT162B2 vaccine, the most common adverse reactions reported after first second injections were injections were injection-site pain (in- 93.1% and 92.4% respectively), headache (in 44.6% and 70.2% respectively) and fatigue (in 47.9% and 67.8% respectively).  Regarding the age group of 5-11 years, a Covid-19 vaccination regimen consisting of two 10 ug doses of BNT162B2 administered 21 days apart has proven to be safe, immunogenic and efficacious. In a recent expert consensus on Covid-19 vaccination in the pediatric age group of (withheld), the authors conclude that the common adverse reactions after vaccinations with codi-19 vaccines in children are similar to those after other vaccinations and includes ad include collateral effects, from mild to moderate, which resolved within 24 hour after vaccination. In an interesting meta analysis on the safety and efficacy of Covid-19 vaccine in children and adolescent, including 7 RCTS and 2 observations studies for a total 264674 patients (withheld) have shown that overall effectiveness of the covid-19 vaccine in children is 96.09% and is better than that in adult populations. The development or myocarditis or pericarditis after mRNA vaccines has been documented after vaccine, especially in young adsorbents. Some studies reported an incidence of 6.3-6.7 cases per 100000s vaccine doses in males aged 12-17 years, which increases to 15.1 cases per 100000s vaccine doses in males aged 16-19 years. However, of these patients, most recovered without sequelae and around 6% required intensive care admission. No thrombose and anaphylaxis events were seen in pediatric age, no deaths were reported post vaccine.; Sender's Comments: A possibly contributory role of BNT162B2 in triggering the onset of Adenomesenteritis cannot be fully excluded, considering the temporal relationship.  More epidemiologic data and cumulative safety reports collected post marketing use are needed to indicate if there exists a potential causal link between the vaccination and such occurrence The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate.