Salmonella Aortitis in an Elderly Male, a Rare but Deadly Cause of Abdominal Pain: A Case Report.

INTRODUCTION: Infectious aortitis is a rare condition with mortality rates approaching 100% without surgical intervention. Symptoms and findings may be vague. Computed tomography (CT) with intravenous (IV) contrast, once the gold standard of diagnosis, may only show subtle findings. More recently, CT angiography (CTA) and magnetic resonance angiography have become the diagnostic modalities of choice. CASE REPORT: A 58-year-old diabetic male presented to our emergency department with nausea, vomiting, diarrhea, fevers, and abdominal pain of two weeks duration. The patient had been seen just days before at another facility with the same complaints. He received an abdominal CT with IV contrast that was reported as negative and discharged with the diagnosis of gastroenteritis. He failed to improve and presented to our facility. On presentation, the patient was diaphoretic and uncomfortable. A repeat abdominal CT with IV contrast revealed a mantle of low density around the aorta. The patient was started on IV antibiotics, and a follow-up CTA of the abdomen and pelvis showed an irregular saccular aneurysm. Vascular surgery was consulted, and the patient underwent vascular reconstruction. CONCLUSION: Because of the high level of mortality seen in infectious aortitis and improvement in patient outcomes with surgical intervention, a high index of suspicion needs to be maintained in patients presenting with fever and chest, abdominal, and back pain, especially in the setting of risk factors and bacteremia. The clinician should be aware that the usual modality for the evaluation of abdominal pain, CT with IV contrast, may not be adequate to make the diagnosis.

Role of neurturin in spontaneous itch and increased nonpeptidergic intraepidermal fiber density in a mouse model of psoriasis.

Psoriasis is often accompanied by itch, but the mechanisms behind this symptom remain elusive. Dynamic changes in epidermal innervation have been observed under chronic itch conditions. Therefore, we investigated whether epidermal innervation is altered in the imiquimod-induced psoriasis mouse model, whether blockade of neurotrophic growth factor signaling can reduce these changes, and whether this system can impact psoriatic itch. Over the 7-day time course of imiquimod treatment, the density of epidermal nonpeptidergic nerves significantly increased, whereas the density of peptidergic nerves significantly decreased. The nonpeptidergic epidermal nerves expressed glial cell line-derived neurotrophic factor (GDNF) family receptor GFRα-1 and GFRα-2, the ligand-binding domains for GDNF and neurturin (NRTN). The NRTN mRNA expression was elevated in the skin of imiquimod-treated mice, whereas the GDNF mRNA expression was decreased. Treatment of imiquimod-challenged mice with an NRTN-neutralizing antibody significantly reduced nonpeptidergic nerve density as well as spontaneous scratching. These results indicate that NRTN contributes to an increase in the epidermal density of nonpeptidergic nerves in the imiquimod-induced psoriasis model, and this increase may be a factor in chronic itch for these mice. Therefore, inhibition of NRTN could be a potential treatment for chronic itch in psoriasis.

Mouse model of imiquimod-induced psoriatic itch.

Itch is a major indicator of psoriasis, but the underlying mechanisms behind this symptom are largely unknown. To investigate the neuronal mechanisms of psoriatic itch, we tested whether mice subjected to the imiquimod-induced psoriasis model exhibit itch-associated behaviors. Mice received daily topical applications of imiquimod to the rostral back skin for 7 days. Imiquimod-treated mice exhibited a significant increase in spontaneous scratching behavior directed to the treated area as well as touch-evoked scratching (alloknesis). To characterize this model, we measured the mRNA expression levels of pruritogens and itch-relevant receptors/channels using real-time reverse transcription PCR. The mRNA expression of MrgprA3, MrgprC11, and MrgprD decreased gradually over time in the dorsal root ganglion (DRG) cells. There was no significant change in the mRNA expression of TRPV1 or TRPA1 in DRG cells. TRPV4 mRNA expression was transiently increased in the DRG cells, whereas TRPM8 mRNA was significantly decreased. The mRNA expression levels of histidine decarboxylase and tryptophan hydroxylase 1, as well as the intensity of histamine and serotonin immunoreactivity, were transiently increased in the skin on day 2, returning to baseline by day 7. Histamine H1-receptor antagonists, chlorpheniramine and olopatadine, significantly inhibited spontaneous scratching on day 2, but not day 7. Neither chlorpheniramine nor olopatadine affected alloknesis on day 2 or day 7. These results may reflect the limited antipruritic effects of histamine H1-receptor antagonists on human psoriasis. The imiquimod-induced psoriasis model seems to be useful for the investigation of itch and its sensitization in psoriasis.