Substance P/ Neurokinin-1 Receptor, Trigeminal Ganglion, Latency, and Coronavirus Infection-Is There Any Link?

Novel Severe Acute Respiratory Syndrome-Corona Virus-2 infection (SARS-CoV-2) is an acute respiratory and infectious disease. This perspective aims to provide a basic understanding of the inflammation caused by SARS-CoV-2 and its relation to the trigeminal ganglion (TG). The virus enters through the mucous membranes of the orofacial region and reaches the TG, where it resides and takes control of its peptides including Substance P (SP). SP is the main neuropeptide, neuromodulator, and neuro-hormone of TG, associated with nociception and inflammation under noxious stimulus. SP release is triggered and, consequently, affects the immune cells and blood vessels to release the mediators for inflammation. Hence, cytokine storm is initiated and causes respiratory distress, bronchoconstriction, and death in complicated cases. Neurokinin-1 Receptor (NK-1R) is the receptor for SP and its antagonists, along with glucocorticoids, may be used to alleviate the symptoms and treat this infection by blocking this nociceptive pathway. SP seems to be the main culprit involved in the triggering of inflammatory pathways in SARS-CoV-2 infection. It may have a direct association with cardio-respiratory rhythm, sleep-wake cycle, nociception, and ventilatory responses and regulates many important physiological and pathological functions. Its over-secretion should be blocked by NK-1R antagonist. However, experimental work leading to clinical trials are mandatory for further confirmation. Here, it is further proposed that there is a possibility of latency in SARS-CoV-2 virus infection if it is acting through TG, which is the main site for other viruses that become latent.

Diagnosis of Adult Onset Still's Disease in a Patient Who has recovered from Coronavirus-19.

INTRODUCTION: Adult Still's disease (ASD) is an uncommon inflammatory disorder characterized by fevers, a salmon-colored rash, and arthritis. Cytokines storm syndrome related to Coronavirus-19 (COVID-19) usually occur in acute period of COVID-19 and can mimic clinical features of ASD. CASE REPORT: We present a case of a 27-year-old male who was hospitalized in July 2020 due to fever, sore throat, multiple joint pain, and body rash for 2 weeks. Patient recovered from COVID-19 8 weeks ago but his nasopharyngeal SARS CoV-2 PCR was still positive on current hospitalization. Post COVID-19 cytokines storm syndrome post COVID-19 was suspected but after further assessment and investigations, diagnosis of ASD was established and patient was treated with corticosteroids therapy and had favorable outcome. CONCLUSION: During COVID-19 pandemic, diagnosis of many other diseases either were delayed or missed. We encourage all clinicians to have a broader differential diagnosis to improve patient care and outcome.