Nummular keratitis: A rare manifestation of brimonidine allergy.

A 32-year-old male, with juvenile open-angle glaucoma on chronic antiglaucoma therapy and recently introduced brimonidine eye drops to the treatment regimen, developed bilateral follicular conjunctivitis with subepithelial infiltrates (SEIs) initially resembling common infectious keratoconjunctivitis entities. The persistent nature of the conjunctivitis, the lack of positive conjunctival cultures, the absence of systemic symptoms, the full resolution of the condition upon discontinuation of antiglaucoma drops, and the commencement of topical steroids, along with the reappearance of SEIs upon reintroducing brimonidine; suggested an immune-mediated drug reaction secondary to a Benzalkonium chloride (BAK) preserved brimonidine tartrate 0.2% formulation. The interval between the initiation of brimonidine and the onset of the drug reaction was 13 months and shortened to 1 week upon re-exposure to the drug. The condition fully resolved without further sequelae off brimonidine. Brimonidine is notoriously known for causing ocular allergic reactions, the most common being follicular conjunctivitis, but very few reports exist describing its adverse effects on the cornea. This case highlights that brimonidine may directly or indirectly induce an immune reaction affecting the cornea in the form of SEIs. Brimonidine is, thus, capable of mimicking more commonly recognized infectious disease entities causing keratoconjunctivitis. This is the second report of a similar manifestation linked to its use.

Early Onset Colorectal Cancer in Arabs, Are We Dealing with a Distinct Disease?

Early-onset colorectal cancer (EOCRC) incidence is increasing worldwide. Efforts are directed to understand the biological and clinical signatures of EOCRC compared to late-onset colorectal cancer (LOCRC). EOCRC is thought to present differently across different ethnic groups and geographical regions. This study was an attempt to contribute with data from the Arab world toward the understanding of the clinicopathological parameters of EOCRC compared to LOCRC. Data from 254 CRC patients diagnosed at Sultan Qaboos University Hospital from the period 2015-2020 were studied. About 32.6% of all diagnosed CRC patients are below 50 years old, with no differences in gender distribution between EOCRC and LOCRC (p-value 0.417). Rectal involvement and tumor laterality were comparable among the two groups. Adenocarcinoma accounts for 83.3% and 94.2% of EOCRC and LOCRC, respectively. More mucinous and signet ring adenocarcinoma (8.3% each) were reported in EOCRC than LOCRC (2.9% and 2.2%, respectively). MLH1 and PMS2 loss are more common among LOCRC, but MSH6 loss is more frequent in EOCRC. The overall survival of EOCRC and LOCRC was comparable (median survival 64.88 and 67.24 months, respectively). This study showed comparable clinicopathological parameters between EOCRC and LOCRC from Arabs, which adds to the bigger picture of understand the disease.

Prevalence and distribution of sesamoid bones of the hand in Omani subjects: a radiological study.

Sesamoid bones show considerable variations in their occurrence among various ethnicities. This study aims to evaluate the prevalence and distribution patterns of the sesamoid bones of the hands among Omani patients who were referred for radiological investigations. The influence of gender and different age groups on the occurrence of sesamoid bones of the hand was determined using the Chi-square test. Spearman's rank correlation was used to determine the coexistence of sesamoid bones at the metacarpophalangeal joints. A total of 541 hand radiographs were reviewed. A high prevalence of sesamoid bones at the fifth metacarpophalangeal joint and the interphalangeal joint of the thumb was noted with a frequency of 64% and 49.7%, respectively. There were ten different patterns of sesamoid bones detected, the most common of which was the presence of sesamoid bones at the first and fifth metacarpophalangeal joints found in 32.9% of the radiographs. A statistically significant gender difference was observed at the interphalangeal joint of the thumb (p = 0.025) and fifth metacarpophalangeal joint (p = 0.027) with a female dominance. A significant association between the age and prevalence of sesamoid bones was noted at the fifth metacarpophalangeal joint (p = 0.03). The prevalence of the sesamoid bones of the hand in Omani subjects seems to differ from other Middle Eastern populations, particularly at the fifth metacarpophalangeal joint and the interphalangeal joint of the thumb. In the meantime, the baseline data of our study can be helpful while treating the patients complaining of hand discomfort or pain.