Systemic and skin-limited delayed-type drug hypersensitivity reactions associate with distinct resident and recruited T cell subsets.

Delayed-type drug hypersensitivity reactions are major causes of morbidity and mortality. The origin, phenotype, and function of pathogenic T cells across the spectrum of severity require investigation. We leveraged recent technical advancements to study skin-resident memory T cells (TRMs) versus recruited T cell subsets in the pathogenesis of severe systemic forms of disease, Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS), and skin-limited disease, morbilliform drug eruption (MDE). Microscopy, bulk transcriptional profiling, and single-cell RNA-sequencing (scRNA-Seq) plus cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq) plus T cell receptor sequencing (TCR-Seq) supported clonal expansion and recruitment of cytotoxic CD8+ T cells from circulation into skin along with expanded and nonexpanded cytotoxic CD8+ skin TRM in SJS/TEN. Comparatively, MDE displayed a cytotoxic T cell profile in skin without appreciable expansion and recruitment of cytotoxic CD8+ T cells from circulation, implicating TRMs as potential protagonists in skin-limited disease. Mechanistic interrogation in patients unable to recruit T cells from circulation into skin and in a parallel mouse model supported that skin TRMs were sufficient to mediate MDE. Concomitantly, SJS/TEN displayed a reduced Treg signature compared with MDE. DRESS demonstrated recruitment of cytotoxic CD8+ T cells into skin as in SJS/TEN, yet a pro-Treg signature as in MDE. These findings have important implications for fundamental skin immunology and clinical care.

ACR Appropriateness Criteria® Soft Tissue Vascular Anomalies: Vascular Malformations and Infantile Vascular Tumors (Non-CNS)-Child.

Soft tissue vascular anomalies may be composed of arterial, venous, and/or lymphatic elements, and diagnosed prenatally or later in childhood or adulthood. They are divided into categories of vascular malformations and vascular tumors. Vascular malformations are further divided into low-flow and fast-flow lesions. A low-flow lesion is most common, with a prevalence of 70%. Vascular tumors may behave in a benign, locally aggressive, borderline, or malignant manner. Infantile hemangioma is a vascular tumor that presents in the neonatal period and then regresses. The presence or multiple skin lesions in an infant can signal underlying visceral vascular anomalies, and complex anomalies may be associated with overgrowth syndromes. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Stigmatization and Mental Health Impact of Chronic Pediatric Skin Disorders.

Importance: Chronic skin disorders in children frequently are visible and can cause stigmatization. However, the extent of stigmatization from chronic skin disease and association with mental health needs further study. Objective: To examine the extent of stigma, dependence on disease visibility and severity, and association with mental health and quality of life (QOL) in chronic pediatric skin disease. Design, Setting, and Participants: A cross-sectional, single-visit study was conducted at 32 pediatric dermatology centers in the US and Canada from November 14, 2018, to November 17, 2021. Participants included patients aged 8 to 17 years with chronic skin disease and 1 parent. Main Outcomes and Measures: Using the Patient-Reported Outcomes Measurement Instrumentation System (PROMIS) Stigma-Skin, the extent of stigma with child-, caregiver-, and physician-assessed disease visibility (primary outcome) and severity was compared, as well as reduced QOL (assessed by Skindex-Teen), depression, anxiety, and poor peer relationships (PROMIS child and proxy tools) (secondary outcomes). Results: The study included 1671 children (57.9% female; mean [SD] age, 13.7 [2.7] years). A total of 56.4% participants had self-reported high disease visibility and 50.5% had moderate disease severity. Stigma scores significantly differed by level of physician-assessed and child/proxy-assessed disease visibility and severity. Among children with chronic skin disorders, predominantly acne, atopic dermatitis, alopecia areata, and vitiligo, only 27.0% had T scores less than 40 (minimal or no stigma) and 43.8% had at least moderate stigma (T score ≥45) compared with children with a range of chronic diseases. Stigma scores correlated strongly with reduced QOL (Spearman ρ = 0.73), depression (ρ = 0.61), anxiety (ρ = 0.54), and poor peer relationships (ρ = -0.49). Overall, 29.4% of parents were aware of bullying of their child, which was strongly associated with stigma (Cohen d = -0.79, with children who were not bullied experiencing lower levels of stigma). Girls reported more stigma than boys (Cohen d = 0.26). Children with hyperhidrosis and hidradenitis suppurativa were most likely to have increased depression and anxiety. Conclusions and Relevance: The findings of this study suggest that physician assessment of disease severity and visibility is insufficient to evaluate the disease impact in the patient/caregiver. Identifying stigmatization, including bullying, and tracking improvement through medical and psychosocial interventions may be a key role for practitioners.

Immunohistochemical Expression of Lymphatic Endothelial Markers in Blue Rubber Bleb Nevus Syndrome.

INTRODUCTION: Blue rubber bleb nevus syndrome (BRBNS) is an uncommon vascular anomaly characterized by multifocal cutaneous, visceral, and other soft tissue or solid organ venous malformations. We observed that BRBNS lesions express immunohistochemical markers of lymphatic differentiation. METHODS: BRBNS histopathologic specimens assessed at our institution during the past 27 years were reviewed. Slides from 19 BRBNS lesions were selected from 14 patients (9 cutaneous, 9 gastrointestinal, and 1 hepatic). We recorded the involved anatomical compartments and presence/absence of thrombi or vascular smooth muscle. Immunohistochemical endothelial expression of PROX1 (nuclear) and D2-40 (membranous/cytoplasmic) was evaluated semi-quantitatively. RESULTS: Endothelial PROX1 immunopositivity was noted in all specimens; the majority (89.5%) demonstrated staining in more than 10% of cells. D2-40 immunopositivity was present in one-third (33%) of cutaneous lesions and only 1 gastrointestinal lesion. CONCLUSION: Endothelial cells in BRBNS almost always express 1 or more immunohistochemical markers of lymphatic differentiation.

Infantile Hemangioma of the Breast: Long-Term Assessment of Outcomes.

Background: The literature is meager regarding the natural history and outcomes of infantile hemangiomas (IHs) in the breast. Treatment in childhood may be considered due to psychosocial and physical concerns with breast development. Early surgical intervention may cause iatrogenic breast asymmetry and possibly impair lactation later in life. This study characterizes the clinical presentation, management, and long-term outcomes of IHs arising in the breast. Methods: Female patients aged 11 years or older at presentation were included in a retrospective review of the Vascular Anomalies Center database for patients with IHs of the breast seen at our institution between 1980 and 2020. Breast development was ascertained by a structured telephone interview, physical examination, or photographs. Results: A total of 10 patients met criteria for inclusion in this study. The median age at enrollment was 14 years (11-36 years). Breast asymmetry was noted in 60% of patients (n = 6). Of the four patients who underwent subtotal excision of breast IH, three developed ipsilateral breast hypoplasia. Breast asymmetry was also noted in three of five patients who did not receive medical treatment: two with hypoplasia and one with hyperplasia. No asymmetry was noted in the single patient who received corticosteroid. Conclusions: IHs involving the nipple-areola complex can be associated with breast asymmetry. Hypoplasia was noted in patients not treated with corticosteroid or resection in childhood. These findings suggest that systemic treatment should be considered. Longitudinal follow-up on patients treated with propranolol will elucidate its possible benefits in minimizing breast asymmetry.

Multicenter Study of Long-Term Outcomes and Quality of Life in PHACE Syndrome after Age 10.

OBJECTIVE: To characterize long-term outcomes of PHACE syndrome. STUDY DESIGN: Multicenter study with cross-sectional interviews and chart review of individuals with definite PHACE syndrome ≥10 years of age. Data from charts were collected across multiple PHACE-related topics. Data not available in charts were collected from patients directly. Likert scales were used to assess the impact of specific findings. Patient-Reported Outcomes Measurement Information System (PROMIS) scales were used to assess quality of life domains. RESULTS: A total of 104/153 (68%) individuals contacted participated in the study at a median of 14 years of age (range 10-77 years). There were infantile hemangioma (IH) residua in 94.1%. Approximately one-half had received laser treatment for residual IH, and the majority (89.5%) of participants were satisfied or very satisfied with the appearance. Neurocognitive manifestations were common including headaches/migraines (72.1%), participant-reported learning differences (45.1%), and need for individualized education plans (39.4%). Cerebrovascular arteriopathy was present in 91.3%, with progression identified in 20/68 (29.4%) of those with available follow-up imaging reports. Among these, 6/68 (8.8%) developed moyamoya vasculopathy or progressive stenoocclusion, leading to isolated circulation at or above the level of the circle of Willis. Despite the prevalence of cerebrovascular arteriopathy, the proportion of those with ischemic stroke was low (2/104; 1.9%). PROMIS global health scores were lower than population norms by at least 1 SD. CONCLUSIONS: PHACE syndrome is associated with long-term, mild to severe morbidities including IH residua, headaches, learning differences, and progressive arteriopathy. Primary and specialty follow-up care is critical for PHACE patients into adulthood.

Non-vascular intracranial lesions in three children with PHACE association.

PHACE (posterior fossa malformations, hemangiomas, arterial anomalies, cardiac anomalies, eye anomalies) association has many recognized clinical features. A link between PHACE and non-vascular intracranial lesions has not been well-described. We report three pediatric patients with PHACE and non-vascular intracranial lesions.

Next generation sequencing aids diagnosis and management in a case of encephalocraniocutaneous lipomatosis.

Encephalocraniocutaneous lipomatosis (ECCL) is a rare neurocutaneous disorder caused by somatic FGFR1 and KRAS variants. It shares significant phenotypic overlap with several closely related disorders caused by mutations in the RAS-MAPK pathway (mosaic RASopathies). We report a diagnostically challenging case of ECCL in which next-generation sequencing of affected tissue identified a pathologic FGFR1 p.K656E variant, thereby establishing a molecular diagnosis. Patients with FGFR1-associated ECCL carry a risk of developing malignant brain tumors; thus, genetic testing of patients with suspected ECCL has important management implications.

Spectrum of lymphatic anomalies in patients with RASA1-related CM-AVM.

BACKGROUND: Capillary malformation-arteriovenous malformation (CM-AVM) is characterized by multifocal fast-flow capillary malformations, sometimes with arteriovenous malformations/fistulas, skeletal/soft tissue overgrowth, telangiectasias, or Bier spots. Lymphatic abnormalities are infrequently reported. We describe seven patients with CM-AVM and lymphatic anomalies. METHODS: Following IRB approval, we identified patients with CM-AVM and lymphatic anomalies seen at the Vascular Anomalies Center at Boston Children's Hospital from 2003 to 2023. We retrospectively reviewed records for clinical, genetic, laboratory, and imaging findings. RESULTS: We found seven patients with CM-AVM and lymphatic abnormalities. Five patients were diagnosed prenatally: four with pleural effusions (including one suspected chylothorax) and one with ascites. Pleural effusions resolved after neonatal drainage in three patients and fetal thoracentesis in the fourth; however, fluid rapidly reaccumulated in this fetus causing hydrops. Ascites resolved after neonatal paracentesis, recurred at 2 months, and spontaneously resolved at 5 years; magnetic resonance lymphangiography for recurrence at age 19 years suggested a central conducting lymphatic anomaly (CCLA), and at age 20 years a right spermatic cord/scrotal lymphatic malformation (LM) was detected. Chylous pericardial effusion presented in a sixth patient at 2 months and disappeared after pericardiocentesis. A seventh patient was diagnosed with a left lower extremity LM at 16 months. Six patients underwent genetic testing, and all had RASA1 mutation. RASA1 variant was novel in three patients (c.1495delinsCTACC, c.434_451delinsA, c.2648del), previously reported in two (c.2603+1G>A, c.475_476del), and unavailable in another. Median follow-up age was 5.8 years (4 months-20 years). CONCLUSION: CM-AVM may be associated with lymphatic anomalies, including pericardial/pleural effusions, ascites, CCLA, and LM.

Metopic ridge presenting to pediatric dermatology and vascular anomalies clinics.

Metopic ridge (MeR) is a midline osseous forehead prominence resulting from physiologic closure of the underlying metopic suture. This mass-like ridge can be mistaken for serious conditions such as a craniosynostosis or vascular anomaly, prompting concern and workup. We reviewed patients presenting for a forehead mass to Vascular Anomalies and Dermatology clinics and diagnosed with MeR to increase familiarity with this finding and to encourage MeR in the differential diagnosis of pediatric midline forehead masses.

Paradoxical Psoriasiform Eruptions in Children Receiving Tumor Necrosis Factor α Inhibitors.

Importance: Tumor necrosis factor α (TNF) inhibitor-induced psoriasiform eruption is well recognized in adults, but few reports document this paradoxical effect in children. Objective: To characterize the clinical features and the clinical time course of TNF inhibitor-induced psoriasiform eruptions in children. Design, Setting, and Participants: A multicenter retrospective case series of children younger than 18 years seen between January 1, 2000, and December 31, 2016, who developed a new-onset psoriasiform eruption while taking a TNF inhibitor for a nondermatologic disorder. Participating sites were members of the Pediatric Dermatology Research Alliance. Data were entered into a Research Electronic Data Capture database at the Mayo Clinic (ie, the coordinating center). Results: Psoriasiform eruptions were identified in 103 TNF inhibitor-treated patients (median age, 13.8 years [IQR, 11.7-16.4 years]; 52 female patients [50%]; 57 White patients [55%]), with 67 patients (65%) treated with infliximab, 35 (34%) with adalimumab, and 1 (1%) with certolizumab pegol. Most patients had no personal history (101 [98%]) or family history of psoriasis (60 patients [58%]). Inflammatory bowel disease was the most common indication for treatment with TNF inhibitor (94 patients [91%]). The primary extracutaneous disease was under control in 95 patients (92%) who developed the eruption. Most patients (n = 85 [83%]) developed psoriasiform eruptions at multiple anatomic sites, with scalp involvement being most common (65 patients [63%]). Skin disease developed at a median of 14.5 months (IQR, 9-24 months) after TNF inhibitor initiation. To treat the psoriasiform eruption, topical steroidal and nonsteroidal medication was prescribed for all patients. Systemic therapy was added for 30 patients (29%): methotrexate for 24 patients (23%), oral corticosteroids for 8 patients (8%), and azathioprine for 1 patient (1%). For 26 patients (25%), suboptimal effectiveness with topical medications alone prompted discontinuation of the initial TNF inhibitor and a change to a second-line TNF inhibitor with cutaneous improvement in 23 patients (88%) by a median of 3 months (IQR, 2-4 months). Eight patients (31%) who started a second-line TNF inhibitor developed a subsequent TNF inhibitor-induced psoriasiform eruption at a median of 6 months (IQR, 4-8 months). Persistent skin disease in 18 patients (17%) prompted discontinuation of all TNF inhibitors; 11 patients changed to a non-TNF inhibitor systemic therapy, and 7 discontinued all systemic therapy. Conclusions and Relevance: In this case series, paradoxical TNF inhibitor-induced psoriasiform eruptions were seen in children treated with TNF inhibitors for any indication, and there appears to be a class effect among the varying TNF inhibitors. The majority of these children were able to continue TNF inhibitor therapy with adequate skin-directed and other adjuvant therapies.

Paraneoplastic pemphigus associated with Castleman disease: A multicenter case series.

INTRODUCTION: Paraneoplastic pemphigus (PNP) is a rare, often fatal, autoimmune blistering disease of the skin and mucous membranes. In children, PNP is frequently associated with Castleman disease (CD). This series describes five cases of PNP associated with CD. METHODS: Data were collected retrospectively from the medical records of patients with a diagnosis of PNP and CD from January 2013 to June 2022. Patients ≤22 years old with clinical and immunopathologic evidence of PNP were included; CD was diagnosed histopathologically. RESULTS: Two children, two adolescents, and one young adult (two males, three females) were included. The average age at disease presentation was 11.8 years (range: 7-22 years). Oral (n = 5) and anogenital (n = 3) mucositis were common. Four patients had "unicentric" CD (UCD); one patient had "multicentric" CD (MCD). Castleman tumors were in the retroperitoneum (n = 4) or axilla (n = 1). One patient had myasthenia gravis without thymoma. Three patients had bronchiolitis obliterans (BO). Three patients had complete resection of their CD; two had partial resection. Three patients remain alive with a median follow-up of 13 months (range: 12 months to 13 years); two are clinically stable with resolution of mucocutaneous lesions; one has persistent BO requiring ongoing ventilatory support. Patients who remain alive had UCD with complete resection; all deceased patients had partial resection and BO. CONCLUSION: Most patients had UCD, and the retroperitoneum was the most common location. Patients with MCD, incomplete resection, and BO died; patients with UCD and complete resection remain alive, even in the setting of BO. Consideration of PNP is critical when pediatric patients present with mucositis as PNP may be clinically indistinguishable from more common causes of mucositis.

Kaposiform Lymphangiomatosis: Pathologic Aspects in 43 Patients.

Kaposiform lymphangiomatosis is an uncommon generalized lymphatic anomaly with distinctive clinical, radiologic, histopathologic, and molecular findings. Herein, we document the pathology in 43 patients evaluated by the Boston Children's Hospital Vascular Anomalies Center from 1999 to 2020. The most frequent presentations were respiratory difficulty, hemostatic abnormalities, and a soft tissue mass. Imaging commonly revealed involvement of some combination of mediastinal, pulmonary, pleural, and pericardial compartments and most often included spleen and skeleton. Histopathology was characterized by dilated, redundant, and abnormally configured lymphatic channels typically accompanied by dispersed clusters of variably canalized, and often hemosiderotic, spindled lymphatic endothelial cells that were immunopositive for D2-40, PROX1, and CD31. An activating lesional NRAS variant was documented in 9 of 10 patients. The clinical course was typically aggressive, marked by hemorrhage, thrombocytopenia, diminished fibrinogen levels, and a mortality rate of 21%.

Association of Demographic Factors and Infantile Hemangioma Characteristics With Risk of PHACE Syndrome.

Importance: A 2010 prospective study of 108 infants estimated the incidence of PHACE (posterior fossa malformations, hemangioma, arterial anomalies, cardiac defects, eye anomalies) syndrome to be 31% in children with facial infantile hemangiomas (IHs) of at least 22 cm2. There is little evidence regarding the associations among IH characteristics, demographic characteristics, and risk of PHACE syndrome. Objectives: To evaluate demographic characteristics and comorbidities in a large cohort of patients at risk for PHACE syndrome and assess the clinical features of large head and neck IH that may be associated with a greater risk of a diagnosis of PHACE syndrome. Design, Setting, and Participants: This multicenter, retrospective cohort study assessed all patients with a facial, head, and/or neck IH who were evaluated for PHACE syndrome from August 1, 2009, to December 31, 2014, at 13 pediatric dermatology referral centers across North America. Data analysis was performed from June 15, 2017, to February 29, 2020. Main Outcomes and Measures: The main outcome was presence or absence of PHACE syndrome. Data included age at diagnosis, sex, patterns of IH presentation (including size, segment location, and depth), diagnostic procedures and results, and type and number of associated anomalies. Results: A total of 238 patients (mean [SD] age, 2.96 [4.71] months; 184 [77.3%] female) were included in the analysis; 106 (44.5%) met the criteria for definite (n = 98) or possible (n = 8) PHACE syndrome. A stepwise linear regression model found that a surface area of 25 cm2 or greater (odds ratio [OR] 2.99; 95% CI, 1.49-6.02) and involvement of 3 or more locations (OR, 17.96; 95% CI, 6.10-52.85) to be statistically significant risk factors for PHACE syndrome. Involvement of the parotid gland (OR, 0.39; 95% CI, 0.18-0.85) and segment S2 (OR, 0.38; 95% CI, 0.16-0.91) was associated with a lower risk. Race and ethnicity may also be associated with PHACE syndrome risk, although more studies are needed. Conclusions and Relevance: This cohort study further described factors associated with both a higher and lower risk of PHACE syndrome. The presence of multiple anatomical sites and large surface area were associated with greater risk, whereas S2 or parotid IHs were associated with lower, but still potential, risk. These findings can help in counseling families and decision-making regarding evaluation of infants with large head and neck IHs.

Verrucous Venous Malformation-Subcutaneous Variant.

BACKGROUND: Verrucous venous malformation (VVM), previously called "verrucous hemangioma," typically involves the dermis and the subcutaneous fat. We have encountered patients with VVM confined to the hypodermis. MATERIALS AND METHODS: During a nearly 20-year period, 13 patients, aged 2-17 years, presented with a subcutaneous mass in the limb without clinically obvious epidermal alterations. Consequently, operative excisions did not include the skin. RESULTS: Histopathologically, the specimens were composed of blood-filled channels with morphologic characteristics of capillaries and veins that infiltrated adipose tissue. Aggregates often formed nodules with variable fibrosis and a component of large and radially oriented vessels. A diagnosis of VVM was supported by endothelial immunopositivity for GLUT-1 (25%-75% immunopositive channels in 16/16 specimens); D2-40 (1%-25% channels in 14/15 specimens); and Prox-1 (1%-50% of channels in 14/16 specimens). A MAP3K3 mutation was identified by droplet digital PCR in 3 of the 6 specimens. CONCLUSIONS: Diagnosis of VVM in this uncommon location is challenging because of absence of epidermal changes and lack of dermal involvement. Imaging is not pathognomonic, and mimickers are many. Appropriate immunohistochemical stains and molecular analysis contribute to the correct diagnosis.

Classification of lower extremity venous malformations and risk of knee involvement: A retrospective cohort study.

BACKGROUND: Venous malformation (VM) is the most common vascular anomaly in the lower extremity. VMs can be classified as focal, multifocal, or diffuse types. Intraarticular VM (IA-VM) of the knee portends morbidity. Association of the lower extremity VM type with IA-VM is not well defined. OBJECTIVE: To classify a large cohort of lower extremity, nonsyndromic VMs by type and determine associations with IA-VM. METHODS: Retrospective cohort study. RESULTS: We assessed 156 patients with nonsyndromic, lower extremity VM; 71 (46%) were focal and 85 (54%) were diffuse type VM, and 97 (62%) were IA-VM. Of diffuse VMs, 26 (31%) were Bockenheimer and 59 (69%) were localized subtypes. Pure VM had a significantly elevated risk of IA-VM (relative risk [RR], 2.34; 95% confidence interval [CI], 1.42-3.89). IA-VM was more common in diffuse (73%) versus focal (49%) types. Risk of IA-VM in diffuse type VM was significantly elevated (RR, 1.48; 95% CI, 1.13-1.94). One hundred percent of diffuse Bockenheimer type VM had IA-VM, and this subtype had the highest risk (RR, 1.83; 95% CI, 1.56-2.14) of IA-VM. LIMITATIONS: Retrospective, single-institution study. CONCLUSIONS: Intraarticular involvement of the knee should be considered in all lower extremity VMs. Pure VM and the Bockenheimer diffuse VM subtype had the highest risk of IA-VM.