Background: Nicotinamide is the active form of vitamin B3 (niacin) obtained through endogenous synthesis, mainly through tryptophan metabolism and dietary supplements, fish, meats, grains, and dairy products. It participates in cellular energy metabolism and modulates multiple cellular survival and death pathways. Nicotinamide has been widely studied as a safe chemopreventive agent that reduces actinic keratosis (AKs) and non-melanoma skin cancers (NMSC). Methods: We used the Medline, EMBASE, PubMed, and Cochrane databases to search the concepts “nicotinamide”, “chemoprevention”, and “skin cancer” up to August 2023. Three independent authors screened titles and abstracts for intervention and study design before searching full texts for eligibility criteria. The primary outcome was the impact of oral nicotinamide on the incidence of NMSC in high-risk patients. We also conducted a systematic search to identify relevant epidemiological studies published evaluating dietary niacin intake and the risk of NMSC. Results: Two hundred and twenty-five studies were reviewed, and four met the inclusion criteria. There was no association between NAM consumption and risk for squamous cell carcinoma (SCC) (rate ratio (RR) 0.81, 95% CI 0.48–1.37; I² = 0%), basal cell carcinoma (BCC) (RR 0.88, 95% CI 0.50–1.55; I² = 63%), and NMSC (RR 0.82, 95% CI 0.61–1.12; I² = 63%). Adverse events were rare and acceptable, allowing optimal compliance of patients to the treatment. We found only one article evaluating the association between niacin dietary intake and NMSC risk, supporting a potential beneficial role of niacin intake concerning SCC but not BCC or melanoma. Conclusions: The present meta-analysis shows, by pooling immunocompetent and immunosuppressed patients, that there is insufficient evidence that oral nicotinamide therapy significantly reduces the number of keratinocyte cancers.

Ingesting caustic substances represents a common event which may result in serious injuries of the gastrointestinal system. Severity of injury depends on the type of ingested substance: Caustic burns are more frequently associated with acid ingestion and their severity depends on type, concentration, time of exposure, and amount of the ingested substance. We report a case of phosphoric acid ingestion leading to death in a patient with depressive disorder. While reports ingestion of other acids and organophosphates can be found in the literature, there are no reports detailing a death due to phosphoric acid ingestion. We hope that presenting the findings in this case can aid death investigators in future cases that may involve ingestion of such a substance. After autopsy pH, phosphate and calcium ions concentration in the blood were analyzed. The cause of death was due to systemic effects: metabolic acidosis, hypophosphatemia, hypocalcemia, and hyperkalemia.

Mortality of bullous pemphigoid (BP) is a variable parameter, depending especially on the area where the study was conducted. The 1-year mortality rate and the identification of clinic-therapeutic factors with potential prognostic value in patients with BP were evaluated in a cohort from a single referral center. We have reviewed medical records of patients with BP diagnosed at the Sant' Orsola-Malpighi Hospital in Bologna (Italy) between 2005 and 2019. Data collected included sex, age at diagnosis, laboratory findings, severity of disease, dosage of systemic treatments, age at death and comorbidities. Only patients who had at least 1 year of follow-up were included. Eighty-five patients were included; the mortality rate was 7.1%. The mortality rate of patients treated with a moderate dosage of corticosteroids was no higher than that of patients treated with a low dosage. The log-rank test showed a statistically significant correlation between mortality and patients aged ≥85, BP230 positive, and CCIS≥4. Compared with similar studies, our results show a lower 1-year mortality rate. Advanced age at diagnosis and CCIS were confirmed as major independent factors associated with poor prognosis in BP. Administration of moderate dosage of oral corticosteroids seems to have an overall positive benefit-risk ratio, providing a good control of the disease and minimizing the risk of hospitalization, possible related complications and the mortality rate.