Davis, Dawn M.

ABSTRACT Background Hidradenitis suppurativa (HS) is an inflammatory condition associated with cysts of the folliculopilosebaceous unit primarily affecting intertriginous areas. HS has been correlated with smoke exposure in the adult population, but there is a knowledge gap in understanding its effect in pediatric and adolescent patients. This study assesses correlations between active and passive smoke exposure and the development of HS in the pediatric and adolescent population. Methods A retrospective case–control study was conducted at Mayo Clinic (2010–2023) of patients diagnosed with HS before the age of 18 years who were age‐, sex‐, and race‐matched to healthy controls in a 1:3 ratio, analyzed using Fisher exact for categorical variables and Kruskal–Wallis for continuous. Results One hundred and seventy‐four cases and 522 controls met inclusion criteria. The prevalence of active and passive smoke exposure was significantly higher in patients with HS compared to controls ( p = 0.001), with passive smoke accounting for 64.6% ( N = 31/48) of smoke exposure in patients with HS. Smoke exposure was associated with a significant increase in the odds of an HS diagnosis, with an odds ratio of 4.8 (95% CI: 3.06–7.61) for passive and/or active exposure, and 1.64 (95% CI: 1.01–2.61) for passive exposure alone. Smoke exposure was associated with a later age of diagnosis than those with no smoke exposure ( p < 0.001). Conclusion Prevalence of active and passive smoke exposure was higher in pediatric and adolescent patients with HS compared to age, sex, and race‐matched healthy controls. Smoke exposure increased the odds of having HS and was associated with a later age at diagnosis.

Abstract Background Pemphigoid gestationis (PG) and polymorphic eruption of pregnancy (PEP) are pregnancy‐related dermatoses. Definitive diagnosis often relies upon histopathology and direct immunofluorescence (DIF). PG is associated with fetal and neonatal risks, while PEP confers minimal risk. Objective We aimed to compare histopathologic features to determine key differentiators. Methods A retrospective cohort study of PG and PEP cases, with accompanying DIF, conducted from 1995 to 2020. Skin biopsies were examined independently in a blinded fashion by two dermatopathologists for a list of histopathological features. Results Twenty‐one cases of PG and 10 cases of PEP were identified. PG had significantly denser eosinophils than PEP (mean 155 vs. 48 cells/5 hpf; p < 0.018). PG was also noted to have eosinophilic spongiosis and eosinophils at the dermal–epidermal junction more frequently compared to PEP (80% PG vs. 10% PEP; p < 0.001). A mean cutoff value of 86 eosinophils and a mean optimal sensitivity and specificity of 81% and 83%, respectively, for eosinophils density's diagnostic power of PEP versus PG were achieved. Subepithelial separation was exclusively seen in PG (40% vs. 0%; p < 0.007). Conclusion Eosinophilic spongiosis, eosinophilic epitheliotropism, and dense superficial dermal eosinophils were diagnostic of PG. Given overlapping clinicopathologic features, however, DIF results with clinicopathologic correlation, remain the gold standard.

Abstract: Vascular tumors in infants present a diagnostic and treatment dilemma for both clinicians and pathologists. Infantile hemangioma, the most common vascular tumor in infants, can be confused for other less common vascular tumors in infants. Correct and timely diagnosis is important, as some vascular tumors can be associated with life-threatening coagulopathy. We present the cases of 5 vascular tumors that have clinical and histologic overlap: infantile hemangioma, pyogenic granuloma, noninvoluting congenital hemangioma, tufted angioma, and kaposiform hemangioendothelioma. Typical clinical and histopathologic features of each lesion are summarized. We review the utility and characteristic immunohistochemistry including CD31, CD34, GLUT-1, D2-40, LYVE-1, Prox-1, and WT-1. Collaboration between the clinician and the dermatopathologist correlating the clinical history and histopathologic features can lead to the correct diagnosis, whereas the utility of immunohistochemistry remains in question.