The 2022 world health organization reevaluation of human and mammalian toxic equivalency factors for polychlorinated dioxins, dibenzofurans and biphenyls.

In October 2022, the World Health Organization (WHO) convened an expert panel in Lisbon, Portugal in which the 2005 WHO TEFs for chlorinated dioxin-like compounds were reevaluated. In contrast to earlier panels that employed expert judgement and consensus-based assignment of TEF values, the present effort employed an update to the 2006 REP database, a consensus-based weighting scheme, a Bayesian dose response modeling and meta-analysis to derive "Best-Estimate" TEFs. The updated database contains almost double the number of datasets from the earlier version and includes metadata that informs the weighting scheme. The Bayesian analysis of this dataset results in an unbiased quantitative assessment of the congener-specific potencies with uncertainty estimates. The "Best-Estimate" TEF derived from the model was used to assign 2022 WHO-TEFs for almost all congeners and these values were not rounded to half-logs as was done previously. The exception was for the mono-ortho PCBs, for which the panel agreed to retain their 2005 WHO-TEFs due to limited and heterogenous data available for these compounds. Applying these new TEFs to a limited set of dioxin-like chemical concentrations measured in human milk and seafood indicates that the total toxic equivalents will tend to be lower than when using the 2005 TEFs.

Normocomplementemic urticarial vasculitis secondary to Lyme disease: A rare association with challenging treatment.

Urticarial vasculitis (UV) is a rare entity characterised by long-lasting recurrent episodes of urticarial lesions. Although frequently idiopathic, UV has been associated with multiple diseases, including infections. We present a case of Lyme disease (LD) as a trigger of normocomplementemic UV, a very rarely described association. The patient presented first with episodes of inflammatory polyarthritis and a positive serology for Borrelia burgdorferi, later followed by the appearance of long-lasting urticarial lesions, histologically suggestive of UV. Lyme arthritis resolved with doxycycline, but UV persisted. Response to cyclosporine was satisfactory but with side effects, and only methotrexate showed substantial and consistent improvement. This case reminds physicians that chronic urticaria with atypical characteristics should raise suspicion of UV. Possible triggers for this disease must be sought, even if rarely described, such as LD. Normocomplementemic UV frequently presents a therapeutic challenge, but methotrexate can be a particularly effective therapy in this setting.

Relato de caso de síndrome de Hikikomori em Portugal: uma síndrome primária ou expressão de outra perturbação mental? / Case report of Hikikomori syndrome in Portugal: a primary syndrome or the expression of another mental disorder?

RESUMO O fenómeno hikikomori, forma de isolamento social grave e prolongado, constitui um desafio diagnóstico. A nível conceptual, alguns autores diferenciam o hikikomori em primário e secundário. Este último conceito é utilizado quando está presente comorbilidade que, pelo menos parcialmente, explique a síndrome, enquanto na ausência de diagnóstico psiquiátrico denomina- se "hikikomori primário". Os autores apresentam um caso clínico português com as mesmas características sociodemográficas e clínicas descritas no Japão. Esse caso ilustra que o hikikomori pode potencialmente ser explicado por uma perturbação psiquiátrica subjacente, nem sempre clara à apresentação, e a importância da avaliação cuidadosa e continuada no tempo, por forma a conseguir o esclarecimento diagnóstico e intervenção terapêutica adequada.

ABSTRACT Diagnosing hikikomori, a form of severe and prolonged social withdrawal, is challenging. Conceptually speaking, some authors differentiate "primary" and "secondary" hikikomori. The latter term has been used when there is co-morbidity that at least partially explains the syndrome, whereas in the absence of a psychiatric diagnosis it is called "primary hikikomori". The authors present a Portuguese case report with the same sociodemographic and clinical characteristics described in Japan. This case illustrates that hikikomori can potentially be explained by an underlying psychiatric disorder that is not always clear at the presentation and the importance of careful and continuous assessment, in order to achieve diagnostic clarification and adequate therapeutic intervention.

Rare case of otomastoiditis due to Coxiella burnetii chronic infection.

Q fever is a zoonotic disease caused by Coxiella burnetii that usually presents with non-specific or benign constitutional symptoms. Diagnosis is often challenging and, after acute Q fever, 1%-5% of patients can develop chronic disease. We present an 80-year-old male patient who was admitted due to a 3 months history of fever, productive cough, myalgia, weight loss, headache and hearing loss. Chronic Q fever was confirmed by positive antiphase I immunoglobulin G. Frequent locations of chronic infection was discarded, and ear CT revealed a right mastoid infection. He was treated with doxycycline and hydroxychloroquine for 18 months with significant improvement. This is a rare case of chronic Q fever presenting with otomastoiditis that has never been described.

When a Goitre is a Thyroid Lymphoma.

Primary thyroid lymphoma is a rare cause of both thyroid malignancy and extra-nodal lymphoma. It typically presents as a rapidly enlarging goitre with compressive symptoms. Histological analysis of a biopsy specimen is necessary to confirm the diagnosis. Awareness of this disease is important for early diagnosis and appropriate treatment. A 55-year-old man was admitted due to a 3-month history of cervical enlargement, facial and periorbital oedema and dyspnoea, apparently due to a superior vena cava syndrome. However, cervical ultrasound showed asymmetrical thyroid enlargement, lobulated contours and a hypoechogenic texture. A neck CT scan showed calibre reduction of the superior vena cava. The diagnosis of primary thyroid lymphoma was confirmed by open biopsy of the thyroid gland. The patient started treatment with rituximab with clinical improvement. LEARNING POINTS: Primary thyroid lymphoma is rare, accounting for less than 5% of thyroid malignancies and less than 2% of extra-nodal lymphomas, but should be suspected in the presence of a rapidly enlarging goitre.Fine needle aspiration biopsy is the initial technique of choice, but core needle biopsy or open surgical biopsy may be necessary to establish the diagnosis.Treatment and prognosis are dependent on accurate histological classification, with the disease generally treated successfully with chemotherapy.

Severe post-influenza (H1N1) encephalitis involving pulvinar nuclei in an adult patient.

Neurological complications of H1N1 infections are mostly found in children, but rare cases of acute encephalopathy and post-infectious encephalitis such as acute disseminated encephalomyelitis (ADEM) have been described in adults. We report a case of an adult presenting with a progressive and severe encephalopathy that developed after H1N1 respiratory infection resolution. Cerebrospinal fluid (CSF) analysis was normal, including negative PCR for herpes simplex virus, H1N1, influenza B and JC virus, and absent oligoclonal IgG bands in CSF and serum. Initial CT scan was normal, but later MRI showed posterior multifocal leucoencephalopathy with pulvinar sign. The delayed neurological findings together with the ancillary investigation, namely the MRI pattern with both grey and white matter involvement, raised the possibility of a post-infectious process, rather than an acute encephalitis. Despite aggressive immunotherapy, the patient experienced severe neurological sequelae. Early recognition of ADEM manifestations by those dealing with H1N1 infection is important as early immunotherapy may improve the prognosis.

Dementia in a patient with Thymoma and hypogammaglobulinaemia (Good's syndrome).

Good's syndrome is extremely rare and refers to an acquired B and T cell immunodeficiency in thymoma patients. The authors of this article present a case report of a 75-year-old, caucasian male patient previously subjected to examinations for secondary dementia and recurrent infections, which revealed paraneoplastic syndrome arose from thymoma. He underwent thymectomy, while his immunodeficiency syndrome sustained with frequent opportunistic infections, constantly requiring intravenous immunoglobulin treatment.

The methylenetetrahydrofolate reductase (MTHFR) 677C-->T mutation and cardiovascular risk--A case of ischemic stroke and acute myocardial infarction.

The authors report the case of a 39-year-old male patient who had an ischemic stroke (complete infarction of right anterior cerebral circulation) and an acute myocardial infarction during the same year. Molecular study revealed he was homozygous for the 677C-->T mutation in the gene coding for methylenetetrahydrofolate reductase, a key enzyme of folate metabolism; deficiency of this enzyme is associated with increased cardiovascular risk and neurological lesions. Some considerations are put forward about hyperhomocysteinemia and the MTHFR 677C-->T mutation as cardiovascular risk factors.