Histopathologic Findings of Evolving Mpox Lesions.

ABSTRACT: This article reports two cases of the 2022 mpox virus with notable histopathology, and includes a novel description of mpox pseudotumor in the perianal region which is not previously described. This article additionally includes literature review of characteristic histopathology through evolving lesions, as it is sparsely described in relation to the 2022 mpox outbreak. Case one describes a 42-year-old man who presented with umbilicated, smooth papules on the trunk and extremities, and milia-like papules on the face. Histopathology of an umbilicated lesion revealed epidermal acanthosis with keratinocyte pallor, ballooning degeneration, keratinocyte necrosis, and neutrophilic epitheliotropism. Case two describes a 51-year-old man who presented with scattered eroded papules as well as a perianal mass. Histopathology of the mass revealed ulceration with keratinocyte enlargement and pallor with a mixed inflammatory cell infiltrate. It additionally revealed rare multinucleated keratinocytes with nuclear molding. These cases are remarkable and contribute to literature as reports of the histopathology of the atypical 2022 mpox outbreak are rare. A combination of clinical, laboratory, and histopathologic evidence is useful in diagnosing mpox, and these cases contribute to describing the evolution of viral lesions.

Acute Interstitial Inflammation on Skin Biopsies and Positive Tissue Cultures in Cellulitis Patients Are Associated a Worse Prognosis.

BACKGROUND: Cellulitis is a significant public health burden and lacks a gold standard for diagnosis. Up to 1/3 of patients are incorrectly diagnosed. The skin biopsy has been proposed as the gold standard. OBJECTIVE: In this study, we evaluate the histopathologic characteristics and tissue culture positivity of biopsies in patients diagnosed with cellulitis seen by our inpatient dermatology consultation service. METHODS: This retrospective cohort study examined patients who were hospitalized with a skin and soft tissue infection at our institution between 2011 and 2020 and underwent a skin biopsy. RESULTS: Those with a positive tissue culture were more likely to die within 30 days compared with those with negative tissue cultures (26% vs. 6%, P = 0.048). Patients who died within 30 days were more likely to have acute interstitial inflammation as a feature on histopathology (38%, P = 0.03). LIMITATIONS: Single institutional design, unintentional exclusion of patients with organism-specific diagnosis, and selection for a medically complex patient population because of the nonroutine collection of biopsies. CONCLUSION: Positive tissue cultures and histopathology showing acute interstitial space inflammation on skin and soft tissue infection (SSTI) biopsies are associated with increased mortality and thus may serve as indicators of poor prognosis.

NCCN Guidelines Insights: Primary Cutaneous Lymphomas, Version 2.2020.

Mycosis fungoides (MF) is the most common subtype of cutaneous T-cell lymphoma (CTCL), and Sézary syndrome (SS) is a rare erythrodermic and leukemic subtype of CTCL characterized by significant blood involvement. Although early-stage disease can be effectively treated predominantly with skin-directed therapies, systemic therapy is often necessary for the treatment of advanced-stage disease. Systemic therapy options have evolved in recent years with the approval of novel agents such as romidepsin, brentuximab vedotin, and mogamulizumab. These NCCN Guidelines Insights discuss the diagnosis and management of MF and SS (with a focus on systemic therapy).

Highlighting a Potential Pitfall: Positive Treponema pallidum Immunohistochemical Stain in a Patient Without Syphilis.

The Treponema pallidum antibody immunohistochemical (IHC) stain has improved our ability to detect the organism histologically. We present a case of a man with genital condyloma acuminatum with a positive T. pallidum IHC stain but negative T. pallidum serologies and no syphilitic symptoms. It has been shown that the T. pallidum antibody IHC can cross-react, staining other spirochetes, including Borrelia burgdorferi and the Brachyspira family of intestinal spirochetes. Because of the proximity of our patient's lesions to the anus, and the persistently negative T. pallidum serologies, we believe nontreponemal spirochetes colonized the condyloma, giving a false-positive T. pallidum IHC. This cross-reactivity is a potential diagnostic pitfall and is important for the dermatopathologist to recognize, thereby avoiding false diagnosis of syphilis.

Symmetrical drug-related intertriginous and flexural exanthema with high-risk systemic features: a unique clinical phenotype in hospitalized patients.

Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) is classically considered a low-risk, self-limiting eruption lacking systemic manifestations and sparing facial and mucosal areas. We present 7 inpatients meeting diagnostic criteria for SDRIFE with concomitant systemic manifestations ± high-risk facial involvement acutely after antibiotic exposure (mean latency 6.71 days). These cases deviate from classic, self-limited SDRIFE and represent a unique phenotype of SDRIFE, characterized by coexisting extracutaneous manifestations. Onset of systemic stigmata coincided with or preceded cutaneous involvement in 4 and 3 patients, respectively. All patients developed peripheral eosinophilia and 6 patients had ≥ 2 extracutaneous systems involved. Facial involvement, a high-risk feature associated with severe cutaneous adverse reactions but atypical in classic SDRIFE, occurred in 4 cases. Patients had favorable clinical outcomes following drug cessation and treatment with 4-6 week corticosteroid tapers. We suggest that baseline labs be considered in hospitalized patients with antibiotic-induced SDRIFE. These patients may also necessitate systemic therapy given extracutaneous involvement, deviating from standard SDRIFE treatment with drug cessation alone.

Vancomycin-associated DRESS demonstrates delay in AST abnormalities.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a severe cutaneous adverse drug eruption characterized by rash, fever, lymphadenopathy, hematologic abnormalities, and organ dysfunction. Identifying causative agents and monitoring disease course in DRESS syndrome is crucial to prevent end-organ damage. The temporal relationship between causative medications including vancomycin and laboratory abnormalities in DRESS has not been studied, limiting the utility of laboratory data in monitoring disease course. Our study aims to investigate associations between medication class and peak serum laboratory values using simple linear regression (absolute eosinophils, creatinine, alanine aminotransferase [ALT] and aspartate aminotransferase [AST]). We found a significant difference between timing of peak AST values among vancomycin-triggered DRESS compared to other trigger groups. These findings draw attention to the increased role of AST as a diagnostic and monitoring tool in DRESS.

The United States dermatology inpatient workforce between 2013 and 2019: a Medicare analysis reveals contraction of the workforce and vast access deserts-a cross-sectional analysis.

While time spent practicing inpatient dermatology has decreased since the 1990s, less is known about the current state of inpatient dermatology. We describe the distribution and frequency of inpatient dermatology encounters servicing the United States Medicare population between 2013 and 2019. Cross-sectional analysis of publicly available inpatient Medicare Part B claims data from 2013 to 2019 was conducted. Main outcomes and measures were characteristics and trends of dermatologists performing inpatient encounters. Categorical variables were compared using χ2 analysis. Trends were analyzed for linearity using Pearson correlation coefficient. 782 physicians met inclusion criteria for inclusion. Dermatologists were more often male (56.5%), possessing allopathic Medical Doctorate (MD) (86.3%), and in metropolitan settings (98.2%). However, proportion of female inpatient dermatologists increased significantly (37.9% to 46.2%). Across rural and metropolitan practices, number of inpatient physicians (2013: 356; 2019: 281) and number of medical centers in which dermatology encounters occurred (2013: 239; 2019: 157) decreased, more significantly in non-residency-associated institutions. Spatial analysis revealed wide regions lacking dermatologists meeting defined criteria. Limitations included the need for ten Medicare inpatient encounters for inclusion, counties without reported data. In conclusion, the number of dermatologists performing > 10 inpatient encounters per year is decreasing, and large variations exist in the number of U.S. inpatient dermatology visits.

Histologic features of scalp melanocytic nevi.

BACKGROUND: The scalp has been proposed as an anatomic site that harbors melanocytic nevi with distinctive histologic attributes, so-called "special-site" nevi, similar to nevi on the breast and genitalia. However, detailed studies are lacking. OBJECTIVE: We sought to better delineate the features of scalp melanocytic nevi, particularly lesions that may qualify as special-site nevi. METHODS: The histologic features of 365 total melanocytic nevi of the scalp were studied from 322 patients over a consecutive period of 18 months from July 2007 through January 2009. RESULTS: A total of 56 nevi with characteristic features were identified. The most common features were: (1) random melanocytes containing large nuclei (92.9%) and abundant pale cytoplasm with dusty melanin granules (96.4%); (2) large nests (76.8%) situated along the sides of rete and between rete ridges (85.7%); (3) nests of poorly cohesive melanocytes (82.1%); (4) overlap features with Clark nevi (75.0%); and (5) overlap features with superficial congenital nevi (50.0%). Pagetoid spread (14.3%), asymmetry (23.2%), and poor lateral demarcation (16.1%) were less common. These 56 lesions predominated in the first 2 decades of life and were not observed after age 35 years. LIMITATIONS: Lack of long-term clinical follow-up of patients is a limitation; however, no recurrences or malignancies from these patients' scalps were submitted in the time period (≥ 3 years) since the initial biopsies. CONCLUSION: A special site scalp nevus is recognizable amongst scalp melanocytic nevi, and this lesion is more common in younger patients. Familiarization of its features should assist in the diagnosis and management of scalp melanocytic lesions.

Pustular blastomycosis.

Blastomycosis is an infection caused by the dimorphic fungus Blastomyces dermatitidis. Infection can disseminate to skin, where characteristic ulcerative and verrucous plaques, sometimes studded with pustules, are typically seen. Herein we report 3 patients, two children and one adult, with pustular blastomycosis. Their cutaneous lesions exhibited a pustular morphology at the onset and throughout the course of their illness, without evolution to more typical verrucous or ulcerative plaques. These patients all resided in Memphis, TN, the site of previous case reports of pustular blastomycosis.

Drug Reaction With Eosinophilia and Systemic Symptoms With Pustulosis.

This cohort study examines patients with drug reaction with eosinophilia and systemic symptoms who also have pustules.

Pesticide-associated pemphigus vulgaris.

We present a 40-year-old man with occupation-induced pemphigus vulgaris (PV). He developed PV within days of a one-time heavy exposure to fumes of burning glyphosate, a broad-spectrum nonselective pesticide. This exposure suggests acute cutaneous contact as a stimulus in the development of his pemphigus. While the patient initially required mycophenolate mofetil and prednisone therapy, he has since eliminated contact with pesticides and has been successfully tapered off systemic medication. We discuss the case and review concepts of inducible PV by pesticides and physical cutaneous injury.

Recurrent Staphylococcal Scalded Skin Syndrome in an Extremely Low-Birth-Weight Neonate.

Staphylococcal scalded skin syndrome (SSSS) in premature infants is a rare condition. We present SSSS in an extremely low-birth-weight (ELBW) infant with recurrent and confirmed bacterial sepsis. We present it to emphasize the importance for clinicians to not only recognize the clinical manifestations of SSSS, but also the need to closely monitor infants, especially very low-birth-weight (VLBW) and ELBW infants with SSSS for recurrence and bacterial sepsis. SSSS in preterm infants is a potentially lethal condition and early recognition and appropriate supportive care could be life-saving.

A Case Report of Rash at Peritoneal Dialysis Exit Site.

The International Society for Peritoneal Dialysis recommends the regular application of topical antibiotic-containing preparations in addition to a routine exit site care to reduce the risk of exit site infection (ESI). Among these prophylactic antimicrobial preparations, topical gentamicin is one of the widely used and effective antibiotics for prevention of ESI and peritonitis in peritoneal dialysis (PD) patients. Overall, topical gentamicin is well tolerated; however, its use can be associated with the development of allergic contact dermatitis (ACD). We describe a first reported case of PD catheter exit site contact ACD due to topical gentamicin mimicking ESI. The patient in this report developed worsening violaceous in color and pruritic rash surrounding the PD catheter exit site that appeared 3 weeks after the initiation of gentamicin cream. The association between development of rash and initiation of topical gentamicin led to a suspicion of local reaction to gentamicin rather than ESI. Skin biopsy confirmed ACD. Discontinuation of the provoking agent and subsequent treatment with topical hydrocortisone application led to a resolution of the exit site rash. Any rash at a PD catheter exit site should be considered infectious until proven otherwise. However, it is important to be aware of noninfectious etiologies of exit site rashes as the treatment of these 2 conditions differs.