Polydactylous Squamous Cell Carcinoma of the Nail Unit: A Structured Review of the Literature.

Squamous cell carcinoma of the nail unit (SCCNU) is a rare neoplastic condition that involves multiple digits (polydactylous SCCNU) in only 3.9% of cases. Here, we report a case of polydactylous SCCNU and perform a comprehensive review of MEDLINE and Embase to collate 44 cases of polydactylous SCCNU reported to date. Polydactylous patients were younger on average (48 to 61-63 years) and had a longer diagnostic delay (44 vs 35.1 months) compared with reported monodactylous cases. Human papillomavirus (HPV) positivity was observed in 49% of cases, and the most common serotypes noted were 16 (25.8%), 73 (16.1%), 58 (9.7%), 18 (6.5%), and 33 (6.5%). Twenty percent of the cases were in immunosuppressed individuals who had a statistically significant lower age at diagnosis (39.33 years vs 51.12 years; P = .01) and diagnostic delay (2.50 months vs 132.46 months, P = .04). Patients with HPV positivity had a lower age at diagnosis (43.74 years vs 53.29 years, P = .04). Environmental exposures noted to be associated with polydactylous disease included X-rays, paint/solvents, soluble oils, and stagnant water. This comprehensive literature review serves to characterize polydactylous SCCNU and distinguish the differences in its characteristics to improve diagnosis and clinical recognition.

Coronavirus disease 2019-associated immunoglobulin A vasculitis/Henoch-Schönlein purpura: A case report and review.

Immunoglobulin A (IgA) vasculitis or Henoch-Schönlein purpura is a predominantly pediatric disease occurring after a triggering viral or bacterial infection. Conversely, drug exposure is the most common inciting event in adult cases of IgA vasculitis. Recently, data has suggested a temporal association between coronavirus disease 2019 (COVID-19) and the development of IgA vasculitis in children and adults. Here, we describe a case of IgA vasculitis with nephritis in a 70-year-old man with COVID-19 and perform a comprehensive review of eight reported cases of suspected COVID-19-associated IgA vasculitis. When compared to classical IgA vasculitis, COVID-19-associated IgA vasculitis exclusively affects males (p < 0.00002) and is more common in adults (p < 0.005). Among cases of COVID-19-associated IgA vasculitis, adult cases were associated with significantly more arthralgia than pediatric cases (p = 0.04). In cases where skin biopsy was obtained, direct immunofluorescence (DIF) was negative for IgA in 50% of cases; thereafter, kidney biopsy DIF was positive for IgA in all cases. With this study, we provide support for an association between IgA vasculitis and severe acute respiratory syndrome coronavirus 2 infection and provide clinical information differentiating its manifestations from classical IgA vasculitis.

DPP-4 Inhibitors and Increased Reporting Odds of Bullous Pemphigoid: A Pharmacovigilance Study of the FDA Adverse Event Reporting System (FAERS) from 2006 to 2020.

BACKGROUND: In recent years, an association between dipeptidyl peptidase-4 (DPP-4) inhibitors and bullous pemphigoid has been detected in pharmacovigilance studies in European and Asian countries; however, no pharmacovigilance data have been published yet in the USA. OBJECTIVE: The objective of this study was to examine the relationship between bullous pemphigoid and DPP-4 inhibitors and other oral diabetes mellitus medications in the FDA Adverse Event Reporting System (FAERS). METHODS: Case/non-case analyses were performed in the FAERS using data from 2006 to 2020 to examine the reporting odds ratio (ROR) signal for bullous pemphigoid for all classes of oral diabetes medications. These analyses were performed under multiple conditions to control for bias: (1) comparison to all other drugs in the FAERS; (2) comparison to other diabetes medications; and (3) comparison to all other diabetes medications where only a single agent was implicated. RESULTS: A statistically significant ROR for bullous pemphigoid was found for DPP-4 inhibitors under all conditions: (1) 109.79 (95% confidence interval [CI] 101.61-118.62); (2) 74.46 (95% CI 60.58-91.52); and (3) 35.94 (95% CI 27.91-46.28). A larger signal was seen for non-US Food and Drug Administration (FDA)-approved (anagliptin, vildagliptin, teneligliptin) vs FDA-approved DPP-4 inhibitors (alogliptin, linagliptin, saxagliptin, sitagliptin), likely because of an overestimation of the ROR for non-FDA-approved drugs. The largest signal was seen under conditions 1 and 2 with vildagliptin (1) 1022.83 (95% CI 909.45-1150.35) and (2) 158.84 (95% CI 127.01-198.66) followed by anagliptin (1) 628.63 (95% CI 221.36-1785.24) and (2) 60.64 (95% CI 20.98-175.26), alogliptin, teneligliptin, linagliptin, sitagliptin, and saxagliptin. Under condition 3, the largest signal was seen with linagliptin 122.25 (95% CI 93.96-159.07). Both metformin and the sulfonylureas had a significant ROR under condition 2 [3.42 (95% CI 3.01-3.89) and 2.07 (95% CI 1.66-2.57) respectively]; however, this association was not present under condition 3 as only confounded cases occurred, and a large majority of reported cases had concurrent exposure to a DPP-4 inhibitor. CONCLUSIONS: Our findings support an association between DPP-4 inhibitors and bullous pemphigoid. This association was maintained under controls to limit bias and falsely elevated signal, including controlling for disease state and cases with multiple drug exposures. Non-FDA-approved DPP-4 inhibitors had a larger ROR compared with FDA-approved DPP-4 inhibitors, likely owing to fewer reported adverse effects overall for non-FDA-approved drugs in FAERS.