Microscopic colitis, a forgotten condition: a clinical case and review of the literature.

OBJECTIVE: Microscopic colitis is a not uncommon chronic inflammatory disease of the colon, characterized by watery, non-bloody diarrhea, which is often forgotten and misdiagnosed. CASE PRESENTATION: In this paper, we present a puzzling case of relapsing chronic diarrhea triggered by non-steroidal anti-inflammatory drug (NSAID) abuse, smoking, inappropriate antibiotic use, and secondary Clostridium Difficilis infection. Several tests were performed during hospitalization, all of which were negative apart from fecal calprotectin (> 6,000 mg/kg, normal values < 50 mg/kg) and a positive Clostridium Difficilis toxin test. Since Vancomycin treatment did not bring about the expected response, colonoscopy was performed, which led to diagnosis, targeted therapy, and clinical resolution. Targeted therapy with budesonide and probiotics was initiated leading to resolution of the diarrhea. CONCLUSIONS: This case study shows how actual diagnosis may be delayed not only due to having to perform differential diagnosis with chronic inflammatory diseases, but also because certainty can only come from histological evidence, which takes time to obtain, especially when the disease's multifactorial nature is considered (smoking, NSAID abuse, oral proton pump inhibitors, inappropriate antibiotic use, and Clostridium difficilis infection).

The complexity of immunology: a rare adverse event following a Pfizer-BioNTech vaccine booster shot.

OBJECTIVE: Several mRNA vaccines have been developed to tackle the global pandemic. Despite their remarkable clinical efficacy, they are not devoid of severe short- and long-term adverse events. CASE PRESENTATION: In this paper, we describe a rare delayed adverse event (arterial and venous renal thrombosis with myocardial injury) in an otherwise healthy adult female, which occurred three months after she received a booster shot of Pfizer COVID-19 vaccine.  The patient was successfully treated for subacute renal ischemia with intra-arterial urokinase, and her myocardial injury was diagnosed with imaging (contrast-enhanced thoracic CT and cardiac magnetic resonance) and percutaneous coronary intervention. Deferred post-vaccine myocarditis was diagnosed and resolved with steroid therapy. CONCLUSIONS: In this paper, we report a useful clinical case for the pharmacovigilance database. Although scientific evidence confirms that the benefits of vaccination far outweigh the risk of adverse events, we would like to point out how important watchful observation is in the medium and long term, especially when the subject belongs to a specific risk category.