Neutrophilic dermatoses: a review of current treatment options

Mucocutaneous manifestations of inflammatory bowel disease

Mucocutaneous manifestations can be indicative of a variety of gastrointestinal diseases, and the dermatologist needs to know how to recognize them to refer the right patients to the gastroenterologist. Conversely, the gastroenterologist is often confronted with mucocutaneous lesions that raise the question of a possible association with a known digestive disease. Among the extra-intestinal manifestations of inflammatory bowel disease (IBD), mucocutaneous manifestations are the most common. This review will provide a breakdown by classifying them into 4 groups: 1) reactive manifestations, which include neutrophilic dermatoses, aphthous stomatitis, erythema nodosum, and vasculitis; 2) Crohn's disease-specific granulomatous skin lesions, which are histologically characterized by tuberculoid granulomas similar to those found in the gastrointestinal tract; 3) nutritional deficiency manifestations secondary to anorexia, malabsorption, loss, and drug interactions; and 3) a variety of autonomous autoimmune or inflammatory skin diseases. Dermatologists may also be involved in the management of the adverse effects of IBD treatments, especially the so-called "paradoxical" psoriatic eruptions.

Longitudinal Presentation and Management of Neutrophilic Dermatosis of the Dorsal Hand: A Case Report Over Six Visits

Neutrophilic dermatosis of the dorsal hands (NDDH) is a rare, challenging condition characterized by its acute febrile onset, neutrophilic dermal infiltrate seen on histology, and frequent association with hematologic disorders. This case report presents a longitudinal follow-up of NDDH in an 80-year-old male with significant comorbid conditions, including atrial fibrillation, chronic systolic heart failure, venous insufficiency, and gastroesophageal reflux disease. Over six clinic visits, we document the patient's clinical progression, highlighting key changes in presentation, diagnostic findings, and the multifaceted approach to management, including the use of systemic and topical therapies. Notably, the treatment strategy was adapted in response to diagnostic tests revealing methicillin-resistant Staphylococcus aureus (MRSA) and Group B Streptococcus (GBS), complicating the patient's condition. Despite the challenges posed by the patient's comorbidities, which limited the use of certain medications, the patient showed significant improvement with a treatment approach primarily involving topical and systemic steroids. The observed improvement emphasizes the effectiveness of modifying therapy based on lesion regression and the patient's overall condition. This case underscores the critical need for accurate diagnosis, the complexities of managing NDDH in patients with multiple health conditions, and the value of adaptability in treatment plans. Through this detailed longitudinal case study, we contribute insights into the progression and management of NDDH, emphasizing the need for ongoing research and a flexible approach to treatment.

Rare Autoinflammatory Neutrophilic Dermatoses in Pregnancy: Literature Review

Rare cases of autoinflammatory neutrophilic dermatoses (AINDs) have been reported in patients during pregnancy with associated adverse maternal and fetal outcomes. Due to the rarity and heterogeneous morphology of pregnancy-associated AINDs, clinical diagnosis is often overlooked, and treatment options are limited. In this review, we present the epidemiology, clinical characteristics, therapeutic interventions, maternal and fetal outcomes, and discuss the possible pathophysiology of various pregnancy associated AINDs. Risk factors for the onset and exacerbation of AINDs in pregnancy include older maternal age, disease duration, and specific gestational age. The varied disease courses and conflicting clinical outcomes in both mothers and fetuses demonstrate the importance of symptom recognition and the understanding of the role of pregnancy on AINDs.

Emerging Role of the IL-36/IL-36R Axis in Multiple Inflammatory Skin Diseases

IL-36 is a most recent member of the IL-1 cytokine family, primarily expressed at barrier sites of the body such as the skin, lungs, and intestine. It plays a vital role in inflammation and is implicated in the development of various cutaneous; intestinal; and pulmonary disorders, including psoriasis, inflammatory bowel disease, and chronic obstructive pulmonary disease. IL-36 comprises 4 isoforms: the proinflammatory IL-36α, IL-36β, and IL-36γ and the anti-inflammatory IL-36R antagonist. An imbalance between proinflammatory and anti-inflammatory IL-36 isoforms can contribute to the inflammatory fate of cells and tissues. IL-36 cytokines signal through an IL-36R heterodimer mediating their function through canonical signaling cacade, including the NF-B pathway. Prominent for its role in psoriasis, IL-36 has recently been associated with disease mechanisms in atopic dermatitis, hidradenitis suppurativa, neutrophilic dermatoses, autoimmune blistering disease, and Netherton syndrome. The major cutaneous source of IL-36 cytokines is keratinocytes, pointing to its role in the communication between the epidermis, innate (neutrophils, dendritic cells) immune system, and adaptive (T helper [Th]1 cells, Th17) immune system. Thus, cutaneous IL-36 signaling is crucial for the immunopathological outcome of various skin diseases. Consequently, the IL-36/IL-36R axis has recently been recognized as a promising drug target for the treatment of inflammatory disorders beyond psoriasis. This review summarizes the current update on IL-36 cytokines in inflammatory skin diseases.

Annular neutrophilic dermatoses

Neutrophilic dermatoses (NDs) constitute a group of diseases characterized by sterile neutrophilic infiltrations. Many NDs usually present with infiltrated erythematous plaques, nodules, urticarial plaques, or pustules. Lesions may show variability, and atypical presentations may develop among NDs. Annular lesions have been reported in many NDs and may lead to diagnostic problems. Clinical features and histopathologic findings such as localization of the neutrophilic infiltrate, existence of other cell types, and absence of true vasculitis may be helpful to distinguish NDs. Some of these NDs are associated with infections, inflammatory diseases, and malignancies. In most NDs, systemic steroids and dapsone are very effective and usually first choices. Colchicine, antimicrobials such as doxycycline, tetracycline, and sulfapyridine, and other immunosuppressants such as cyclosporin, methotrexate, and mycophenolate mofetil have been used successfully in treating many NDs. Tumor necrosis factor α inhibitors have also been used successfully in treating many NDs. Janus kinase inhibitors are effective in CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature) syndrome, anakinra in neutrophilic urticarial dermatosis, and intravenous immunoglobulin in resistant pyoderma gangrenosum. We discuss the diagnosis and management of NDs that may present with annular lesions.

Sweet Syndrome Associated with Myelodysplastic Syndrome-A Review of a Multidisciplinary Approach

Sweet syndrome (SS) is a rare disease described as a febrile neutrophilic dermatosis with acute onset, the pathogenesis of which has not yet been elucidated. The syndrome is characterized by the sudden onset of erythematous infiltrated papules or plaques located on the upper body and is associated with fever, leukocytosis and neutrophilia. The lesions show a dense dermal infiltration with mature neutrophils. The condition is responsive to systemic steroids. The central nervous system, bones, muscles, eyes, ears, mouth, heart, lung, liver, kidneys, intestines, and spleen may be affected by SS as extracutaneous manifestations. More and more cases have been found to be associated with malignancies, particularly myelodysplastic syndrome, and, less frequently, other hematologic malignancies or solid tumors. Approximately 21% of patients with SS have an associated malignancy and up to 80% of MASS cases are associated with hematological diseases, predominantly myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Myelodysplastic syndrome is a clonal disease of the bone marrow characterized by inefficient hematopoiesis, dysplasia of the bone marrow and peripheral cytopenias. Affected patients have a high risk of leukemic transformation. After analyzing later studies and current practical aspects regarding MDS-related SS, we suggest an algorithm for evaluating these patients.

CD47 halts Ptpn6-deficient neutrophils from provoking lethal inflammation

Mice with SHP1 proteins, which have a single amino acid substitution from tyrosine-208 residue to asparagine (hereafter Ptpn6^spin mice), develop an autoinflammatory disease with inflamed footpads. Genetic crosses to study CD47 function in Ptpn6^spin mice bred Ptpn6^spin × Cd47^-/- mice that were not born at the expected Mendelian ratio. Ptpn6^spin bone marrow cells, when transferred into lethally irradiated Cd47-deficient mice, caused marked weight loss and subsequent death. At a cellular level, Ptpn6-deficient neutrophils promoted weight loss and death of the lethally irradiated Cd47^-/- recipients. We posited that leakage of gut microbiota promotes morbidity and mortality in Cd47^-/- mice receiving Ptpn6^spin cells. Colonic cell death and gut leakage were substantially increased in the diseased Cd47^-/- mice. Last, IL-1 blockade using anakinra rescued the morbidity and mortality observed in the diseased Cd47^-/- mice. These data together demonstrate a protective role for CD47 in tempering pathogenic neutrophils in the Ptpn6^spin mice.

Resistant Chronic Spontaneous Urticaria - A Case Series Narrative Review of Treatment Options

Background

Chronic spontaneous urticaria (CSU) can be extremely debilitating to the patient and challenging for the treating clinician. The National Institute of Health and Clinical Excellence (NICE) in the United Kingdom (UK) recommendation of omalizumab for patients who fail to respond to high-dose anti-histamines has improved treatment options and quality of life. However, there is still lack of clear guidelines for treatment of patients resistant to standard and anti-IgE therapies.

Methods

We discuss the therapeutic strategies employed among nine extremely resistant CSU cases and the heterogeneity between guidelines from different societies.

Results

Patients with anti-histamine-resistant urticaria either remained on omalizumab or started on immunosuppressive drugs (dapsone or ciclosporin) when they stopped responding to omalizumab. We used clinical assessment, skin biopsies (when available) and previous published reports to consider dapsone (for predominantly neutrophilic infiltration), or ciclosporin at doses between 2 and 4 mg/kg/day. One patient with ciclosporin-resistant urticaria responded to mycophenolate mofetil. Two patients remain on long-term omalizumab due to its relative safety and efficacy including 1 patient with underlying antibody deficiency where omalizumab was preferred over risks of using immunosuppressive medications.

Conclusions

These case studies bring to light the real-world difficulties in managing patients with resistant CSU and the need for generating the evidence base on alternative therapeutic options such as synergistic use of biologics and immunosuppressive drugs.

Neutrophilic Dermatosis and Management Strategies for the Inpatient Dermatologist

Purpose of Review

Neutrophilic dermatoses are a heterogeneous group of disorders with significant overlap in associated conditions, clinical presentation, and histopathologic features. This review provides a structural overview of neutrophilic dermatoses that may present in the inpatient setting along with diagnostic work-up and management strategies.

Recent Findings

Sweet's syndrome has been found in patients with coronavirus disease 2019 (COVID-19). Pyoderma gangrenosum (PG) has been shown to be equally associated with ulcerative colitis and Crohn's disease. A clinical trial shows that cyclosporine is equally effective as prednisone in treating PG. Neutrophilic eccrine hidradenitis has been found in the setting of newer antineoplastic medications, such as BRAF inhibitors, as well as in the setting of malignancy without chemotherapy exposure.

Summary

Neutrophilic dermatoses are a rare and complex group of dermatoses with varying and overlapping clinical presentations. Physicians should be aware of the growing list of associated diseases in order to build a better differential diagnosis or to potentially investigate for co-existing disease.

A Case Report of Necrotizing Neutrophilic Dermatosis: A Sheep in Wolf's Clothing

Neutrophilic dermatosis (ND) is a category of diseases characterized by trauma-induced, autoinflammatory cutaneous eruption. Comorbid systemic disease is common with a predilection for malignancy, inflammatory bowel disease, and rheumatologic disease. Rarely, it can manifest with aseptic shock, an entity referred to as necrotizing neutrophilic dermatosis (NND). NND may occur in the postoperative setting and is often misdiagnosed as a necrotizing soft tissue infection. Unfortunately, the treatment for a necrotizing soft tissue infection, namely, wide debridement, is often detrimental in the setting of NND. We present the case of a woman with underlying myelodysplastic syndrome who developed episodic postoperative hemodynamic collapse followed by delayed necrotic peristomal ulceration following colonic diversion for complicated diverticulitis. Infectious workup and operative re-exploration were unrevealing. Pathologic assessment of affected skin tissue showed changes consistent with ND, ultimately leading to the diagnosis of NND. Her clinical course dramatically improved with the initiation of immunosuppressive therapy. The mimicry of NND to a potentially lethal necrotizing soft-tissue infection creates a grave diagnostic dilemma in the postoperative period. A general lack of knowledge of NND among non-dermatologic specialists produces an opportunity for misdiagnosis and inappropriate surgical interventions, namely, serial debridement. Several clinical cues may aid in the earlier recognition of NND. The cornerstone of treatment involves systemic corticosteroid therapy with adjunctive therapy for refractory cases. NND must be considered in the differential diagnosis of necrotizing soft tissue infection as early recognition may result in the avoidance of deleterious surgical interventions.

Dermatology and Skin Conditions for Hand Surgeons

The hand surgeon must be familiar with all aspects of hand pathology, and while faced with dermatological pathology in daily practice, a comprehensive understanding of skin pathology is often lacking. Dermatological pathology may have an impact on the hand surgeon in multiple ways-before surgery (requiring optimization), after surgery, or by mimicking surgical pathology (whereby surgical management may be contraindicated). Adequate knowledge of the basics of dermatology allows for optimal patient care. This review article highlights the common (and the not so common) skin conditions that hand surgeons may encounter in their practice.

Pyoderma gangrenosum after deep inferior epigastric perforator flap: how prompt diagnosis and treatment can avoid surgical debridement and further morbidity

Pyoderma gangrenosum (PG) is a skin disorder characterized by painful, enlarging necrotic ulcers with bluish borders surrounded by advancing zones of erythema. The key histologic feature is neutrophilic infiltration of the superficial and deep layers of the dermis and the absence of microorganisms. Although rare and associated with autoimmune diseases such as rheumatoid arthritis, ulcerative colitis and Crohn's disease, the diagnosis is commonly missed at presentation and patients are often treated for infection with antibiotics and surgical debridement. We present a case of PG in a 51 year-old woman after a deep inferior epigastric perforator (DIEP) flap for breast reconstruction who was promptly diagnosed and treated with steroids with appropriate response. Our case highlights the importance of rapid diagnosis and treatment of this disease to avoid incorrect management including surgical debridement, which can exacerbate the disease and increase its morbidity.

Neutrophilic Dermatoses: a Clinical Update

Purpose of Review

Neutrophilic dermatoses are defined by the presence of a sterile neutrophilic infiltrate on histopathology. This review focuses on the pathogenesis, epidemiology, clinicopathological features, diagnosis, and management of four disorders: Sweet syndrome, pyoderma gangrenosum, Behçet syndrome, and neutrophilic eccrine hidradenitis.

Recent Findings

Recent studies have provided insight into the complex pathogenesis of neutrophilic dermatoses. Evidence supports an intricate interplay of abnormal neutrophil function and inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic predisposition.

Summary

Neutrophilic dermatoses have diverse cutaneous and extracutaneous manifestations and may be associated with significant morbidity and mortality. Common underlying associations include infectious, inflammatory, and neoplastic disorders, as well as drug reactions. Emerging diagnostic and therapeutic frameworks identify an expanding role for biologic and targeted anti-inflammatory therapies.

Sweet's syndrome and mucosal prolapse polyps in a male patient with ulcerative colitis

BACKGROUND

Sweet's syndrome (SS), also known as acute febrile neutrophilic dermatosis, is a rare neutrophilic dermatitis characterized by pyrexia, neutrophilia and painful papulonodular lesions with a neutrophilic dermal infiltrate.

CASE PRESENTATION

We presented a case report of classical SS associated with ulcerative colitis (UC) and mucosal prolapse polyps (MPPs) in a male patient.

CONCLUSIONS

The particularity of this case is the occurrence of MPPs in a male patient with UC and classical SS. We also discussed whether this patient with concurrent Epstein-Barr virus infection could be treated with corticosteroids.

Pyoderma gangrenosum: current state of the problem

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis that presents with rapidly developing, painful skin ulcers hallmarked by undermined borders and peripheral erythema. Epidemiological studies indicate that the average age of PG onset is in the mid-40s, with an incidence of 310 cases per million person-years. PG is often associated with a variety of other immune-mediated diseases, most commonly inflammatory bowel disease and rheumatoid arthritis. The cause of PG is not well understood, but PG is generally considered an autoinflammatory disorder. Studies have focused on the role of T cells, especially at the wound margin; these cells may support the destructive autoinflammatory response by the innate immune system. PG is difficult to diagnose as several differential diagnoses are possible; in addition to clinical examination, laboratory tests of biopsied wound tissue are required for an accurate diagnosis, and new validated diagnostic criteria will facilitate the process. Treatment of PG typically starts with fast-acting immunosuppressive drugs (corticosteroids and/or cyclosporine) to reduce inflammation followed by the addition of more slowly acting immunosuppressive drugs with superior adverse event profiles, including biologics (in particular, anti-tumour necrosis factor agents).

Pyoderma Gangrenosum: A Review of Updates in Diagnosis, Pathophysiology and Management

Pyoderma gangrenosum (PG) is a rare entity that is characterized by infiltration of neutrophils into the dermis, causing the formation of rapidly enlarging, painful and necrotic skin ulcers. The pathophysiology of PG is still poorly understood. However, genetic, autoimmune and autoinflammatory mechanisms have been proposed that could potentially explain the etiology of this ulcerating skin disorder. Early diagnosis and treatment are key, as the disease course is rapidly progressive and can leave disfiguring, cribriform scars. However, the diagnosis of PG proves difficult, firstly because there are multiple variants of the disease and secondly because it is a clinical diagnosis and can appear similar to that of other diseases such as vasculitis, skin/soft tissue infections and malignancy. Additionally, there are no official diagnostic criteria to aid in the recognition of PG, which often leads to significant delays in diagnosis. The treatment of PG consists in immunosuppression. However, due to a lack of standardized guidelines, therapeutic regimens are usually dependent upon the individual clinician’s experience and are based on little evidence. Knowledge of the clinical features and pathophysiology of PG can aid in early diagnosis and targeted treatment strategies, which in turn results in improved patient outcomes.

Skin and Soft Tissue Infections in Non-Human Immunodeficiency Virus Immunocompromised Hosts

Skin and soft tissue infections among the non-human immunodeficiency virus infected immunosuppressed population are a serious and growing concern. Many pathogens can cause cutaneous infections in these patients owing to the highly varied and profound immune deficits. Although patients can be infected by typical organisms, the diversity and antimicrobial-resistant nature of the organisms causing these infections result in significant morbidity and mortality. The diagnostic approach to these infections in immunocompromised hosts can differ dramatically depending on the potential causative organisms. An understanding of new immunosuppressive treatments and evolving antimicrobial resistance patterns are required to optimally manage these difficult cases.

Postsurgical Pyoderma Gangrenosum After Breast Surgery: A Plea for Early Suspicion, Diagnosis, and Treatment

BACKGROUND

Pyoderma gangrenosum (PG) is a rare inflammatory cutaneous disorder. Although PG is a diagnosis of exclusion, prompt recognition is essential to attain the desired outcomes. From an aesthetic standpoint, this is especially critical with breast involvement and other body segments. We present a consecutive case series of four patients who developed PG following breast surgery and responded to early intervention.

METHODS

A chart review identified four patients who were identified as having developed PG after either aesthetic or reconstructive breast surgery. Their histories, associated risk factors, diagnosis, course of treatment, and results were documented. The PubMed database was then searched to find the literature for comparison.

RESULTS

The average time from surgery to the onset of symptoms was 11 days, and the average time from the onset of symptoms to the correct diagnosis of PG was 41 days. The average length of steroid therapy was 25 days. The average time from the initiation of steroids to complete wound closure was 51 days. The average time from the onset of symptoms to complete wound closure bilaterally was 87 days. All wounds healed with conservative management.

CONCLUSION

Postsurgical PG is a rare but recognized cause of postoperative wound breakdown in patients who have undergone plastic surgery procedures to the breast. Early recognition and treatment can facilitate prompt reversal of the inflammatory process leading to complete wound healing and limitation of the morbidity that can be associated with the disease.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Consideration of a Pharmacological Combinatorial Approach to Inhibit Chronic Inflammation in Alzheimer's Disease

A combinatorial cocktail approach is suggested as a rationale intervention to attenuate chronic inflammation and confer neuroprotection in Alzheimer's disease (AD). The requirement for an assemblage of pharmacological compounds follows from the host of pro-inflammatory pathways and mechanisms present in activated microglia in the disease process. This article suggests a starting point using four compounds which present some differential in anti-inflammatory targets and actions but a commonality in showing a finite permeability through Blood-brain Barrier (BBB). A basis for firstchoice compounds demonstrated neuroprotection in animal models (thalidomide and minocycline), clinical trial data showing some slowing in the progression of pathology in AD brain (ibuprofen) and indirect evidence for putative efficacy in blocking oxidative damage and chemotactic response mediated by activated microglia (dapsone). It is emphasized that a number of candidate compounds, other than ones suggested here, could be considered as components of the cocktail approach and would be expected to be examined in subsequent work. In this case, systematic testing in AD animal models is required to rigorously examine the efficacy of first-choice compounds and replace ones showing weaker effects. This protocol represents a practical approach to optimize the reduction of microglial-mediated chronic inflammation in AD pathology. Subsequent work would incorporate the anti-inflammatory cocktail delivery as an adjunctive treatment with ones independent of inflammation as an overall preventive strategy to slow the progression of AD.

Subcorneal pustular dermatosis: Comprehensive review and report of a case presenting during pregnancy

Subcorneal pustular dermatosis (SPD), also known as Sneddon-Wilkinson disease, is a rare, relapsing, sterile pustular eruption of unknown etiology that develops most commonly in middle-aged or mature women. This article reviews the presentation, associations, and management of the condition and highlights advances in pathophysiology. Onset of SPD during pregnancy has not been reported. Herein, we report a case of SPD that developed during pregnancy. The patient was treated with dapsone without complications for her or the fetus. An association between T helper (Th) 17 and Th2 environments in the development of SPD has been advocated. Pregnancy is characterized by a predominance of Th2 responses and increased interleukin-17 levels and thus may favor the development of the condition.

Improved mouse models and advanced genetic and genomic technologies for the study of neutrophils

Mice have been excellent surrogates for studying neutrophil biology and, furthermore, murine models of human disease have provided fundamental insights into the roles of human neutrophils in innate immunity. The emergence of novel humanized mice and high-diversity mouse populations offers the research community innovative and powerful platforms for better understanding, respectively, the mechanisms by which human neutrophils drive pathogenicity, and how genetic differences underpin the variation in neutrophil biology observed among humans. Here, we review key examples of these new resources. Additionally, we provide an overview of advanced genetic engineering tools available to further improve such murine model systems, of sophisticated neutrophil-profiling technologies, and of multifunctional nanoparticle (NP)-based neutrophil-targeting strategies.

[Neutrophilic and pustular dermatoses : New autoinflammatory diseases and syndromes]

This article reviews noninfectious inflammatory dermatoses with mainly neutrophilic infiltrates and the formation of pustules. The infiltrate containing neutrophils may either be mild as in urticaria or very dense, even with leukocytoclasia, as in Sweet syndrome or pyoderma gangrenosum. Neutrophilic infiltrates and pustular eruptions are caused by different noninfectious immunomechanisms. For some of them, mutations have been found (e.g. NLRC4 mutation in cryopyrin-associated periodic syndromes (CAPS) leading to activation of the inflammasome; IL36RN mutation in pustular psoriasis resulting in uncontrolled IL36 signaling). Neutrophilic dermatoses are of high interest, as they may be the cause of underlying benign or malignant conditions. In recent years, efficient targeted therapies have been developed.

Efficacy of acitretin in the treatment of reactive neutrophilic dermatoses in adult-onset immunodeficiency due to interferon-gamma autoantibody

Reactive neutrophilic dermatoses in adult‐onset immunodeficiency due to interferon‐γ autoantibody (AOID) are usually associated with concomitant active opportunistic infections. Data focusing on the treatment of these dermatoses with non‐immunosuppressive drugs are still lacking. The aim of this study was to assess the efficacy and safety of acitretin treatment of reactive neutrophilic dermatoses in AOID. We conducted a retrospective review of all patients with AOID who had reactive neutrophilic dermatoses and had been treated with acitretin from January 2008 to December 2018. In total, 23 patients had been diagnosed with AOID, with 27 episodes of reactive neutrophilic dermatoses (20 episodes of Sweet syndrome and seven episodes of generalized pustular eruption) and treated with acitretin. The median effective dose of acitretin was 10 mg/day. The mean initial response was 5.6 ± 2.3 days. The rash had almost or completely cleared within 2 weeks in 70.4% of patients. One case had developed a reversible acitretin‐induced liver injury with hepatocellular pattern. The median total duration of treatment was 3 months. In conclusion, this study demonstrates the potential role of acitretin as one of the treatments of choice for reactive neutrophilic dermatoses in AOID, attributable to its favorable response and good tolerability.

Ets-2 deletion in myeloid cells attenuates IL-1α-mediated inflammatory disease caused by a Ptpn6 point mutation

The SHP-1 protein encoded by the Ptpn6 gene has been extensively studied in hematopoietic cells in the context of inflammation. A point mutation in this gene (Ptpn6^spin) causes spontaneous inflammation in mice, which has a striking similarity to neutrophilic dermatoses in humans. Recent findings highlighted the role of signaling adapters and kinases in promoting inflammation in Ptpn6^spin mice; however, the underlying transcriptional regulation is poorly understood. Here, we report that SYK is important for driving neutrophil infiltration and initiating wound healing responses in Ptpn6^spin mice. Moreover, we found that deletion of the transcription factor Ets2 in myeloid cells ameliorates cutaneous inflammatory disease in Ptpn6^spin mice through transcriptional regulation of its target inflammatory genes. Furthermore, Ets-2 drives IL-1α-mediated inflammatory signaling in neutrophils of Ptpn6^spin mice. Overall, in addition to its well-known role in driving inflammation in cancer, Ets-2 plays a major role in regulating IL-1α-driven Ptpn6^spin-mediated neutrophilic dermatoses. Model for the role of ETS-2 in neutrophilic inflammation in Ptpn6^spin mice. Mutation of the Ptpn6 gene results in SYK phosphorylation which then sequentially activates MAPK signaling pathways and activation of ETS-2. This leads to activation of ETS-2 target genes that contribute to neutrophil migration and inflammation. When Ets2 is deleted in Ptpn6^spin mice, the expression of these target genes is reduced, leading to the reduced pathology in neutrophilic dermatoses.

TLR4-dependent shaping of the wound site by MSCs accelerates wound healing

We here address the question whether the unique capacity of mesenchymal stem cells to re‐establish tissue homeostasis depends on their potential to sense pathogen‐associated molecular pattern and, in consequence, mount an adaptive response in the interest of tissue repair. After injection of MSCs primed with the bacterial wall component LPS into murine wounds, an unexpected acceleration of healing occurs, clearly exceeding that of non‐primed MSCs. This correlates with a fundamental reprogramming of the transcriptome in LPS‐treated MSCs as deduced from RNAseq analysis and its validation. A network of genes mediating the adaptive response through the Toll‐like receptor 4 (TLR4) pathway responsible for neutrophil and macrophage recruitment and their activation profoundly contributes to enhanced wound healing. In fact, injection of LPS‐primed MSCs silenced for TLR4 fails to accelerate wound healing. These unprecedented findings hold substantial promise to refine current MSC‐based therapies for difficult‐to‐treat wounds.

Recent advances in managing and understanding pyoderma gangrenosum

Pyoderma Gangrenosum (PG) is a rare neutrophilic dermatosis with multiple different clinical presentations and associated comorbidities. PG has historically been a challenging disorder to diagnose, leading to the development of new diagnostic criteria rather than the traditional approach of a diagnosis of exclusion. The pathophysiology is thought to involve both innate and adaptive immune system dysregulation, neutrophilic abnormalities, environmental, and genetic factors. As of today, no gold standard therapy exists for the treatment of PG, and the literature is restricted to mainly case reports, case series, and 2 small randomized clinical trials. Topical, systemic, and biologic therapy, as well as adequate analgesia and proper wound care all play a role in the management of PG. Recent studies have identified additional cytokines and signalling cascades thought to be involved in the pathogenesis of PG, ultimately leading to the development of new targeted therapies. This review will focus on recent advances in the pathophysiology, clinical presentation and associated comorbidities, diagnosis, and management of PG.

Systemic and Autoimmune Diseases

This article reviews the clinical features of systemic and autoimmune diseases affecting the perianal region and its surrounding integumentary structures.

A case of pyoderma gangrenosum in hand surgery

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis that can take many clinical forms. Its diagnosis is difficult and often delayed. We report the case of a 36-year-old man with PG complicating a chemical burn of the wrist. This mode of atypical onset delayed the diagnosis and the initiation of appropriate treatment. This was not sufficient since the patient's hand was amputated at his request because of unbearable pain, and failed treatment. Surgeons should be aware of this pathology in cases of rapidly progressing ulcers, especially if aggravated by repeated debridement.

Sneddon — Wilkinson disease: Review of the modern literature

The article provides a current overview of the correlation between a rare dermatosis — subcorneal pustulosis (Sneddon — Wilkinson disease) — and various diseases of internal organs; features of immunological changes; the role of desmocollin 1, chemoatractants, interleukin-1β, interleukin-6, interleukin-8, interleukin-10, leukotriene B4, tumour necrosis factor-alpha and K5a complement fraction in the pathogenesis of the disease. In this work, the authors describe the features of the clinical picture of the disease, as well as diagnostic criteria, including the use of serum protein electrophoresis. Histological features of the disease are discussed in detail. In addition, modern methods for treating this disease, including the use of dapsone, acitretin, infliximab, PUVA therapy are presented.

Extraintestinal Manifestations of Inflammatory Bowel Disease: Epidemiology, Etiopathogenesis, and Management

PURPOSE OF REVIEW

Extraintestinal manifestations (EIMs) of inflammatory bowel disease (IBD) represent a complex array of disease processes with variable epidemiologic penetrance, genetic antecedents, and phenotypic presentations. The purpose of this review is to provide an overview of primary and secondary EIMs as well as salient treatment strategies utilized.

RECENT FINDINGS

While the genetic antecedents remain incompletely understood, the treatment armamentarium for EIMs has expanded with new pharmaceutical drug classes that effectively treat IBD. EIMs are an increasingly recognized complication of IBD that require prompt recognition, multidisciplinary management, and a multifaceted therapeutic approach. This review highlights the complexities and ramifications of EIM management and offers therapeutic guidance.

Pyoderma gangrenosum after cesarean section treated with skin graft: A case report

RATIONALE

Pyoderma gangrenosum (PG) is a rare skin disease. Pregnancy is a unique physiological condition. Here we report a rare case of PG after cesarean section.

PATIENT CONCERNS

A 32-year-old female presented with wound breakdown 1 day after cesarean section, with progression to a skin ulcer and no response to antibiotic therapy.

DIAGNOSES

We experienced a case of PG after cesarean section. This was initially misdiagnosed as a wound infection, with fever and wound redness as clinical manifestations.

INTERVENTIONS

The patient was initially treated with antibiotics, followed by glucocorticoid and human immunoglobulin therapy. Wound debridement, vacuum sealing negative pressure drainage, skin grafting, and hyperbaric oxygen therapy were also performed.

OUTCOMES

The wound healed without adverse reactions.

LESSONS

When a surgical incision infection does not respond to antibiotic treatment and the culture is negative, PG should be considered.

Neutrophil-Based Delivery Systems for Nanotherapeutics

Neutrophils, the most abundant leukocytes (50-70% of the total leukocytes in circulation), are the major type of cells recruited to sites of inflammation during infection and tumorigenesis, suggesting that neutrophils could contribute to nanotherapeutics for inflammation and cancer therapy. Neutrophil-based delivery has shown great potential in circumventing nanotherapeutics limitations, such as low biocompatibility, short circulation time, and immunogenicity of nanomaterials. In this review, the current development of neutrophil-based nanotherapeutic drugs in the treatment of inflammatory diseases and cancers is summarized. These successful neutrophil-based nanotherapeutic systems indicate that introducing functional nanomaterials into neutrophils and neutrophil-based vesicles may be a promising strategy for improving the nanotherapeutics in more complex conditions. The integration between neutrophils and nanomaterials will create more opportunities for future materials and medical studies.

Sweet's syndrome: a clinical entity need to discriminate against acute haematogenous periprosthetic joint infection

Sweet's syndrome (SS) or acute febrile neutrophilic dermatosis is an uncommon condition. It is characterized by fever, polymorphonuclear leukocytosis, painful erythematous cutaneous plaques, and dense dermal infiltrate of neutrophils without vasculitis at the site of skin lesions. Lesions in SS might enlarge and coalesce with increasing dermal oedema, resulting in pseudo-vesicular appearance mimicking joint infections. Here, a rare case of SS mimicking acute haematogenous periprosthetic infection in a 74-year-old woman with a history of total knee arthroplasty is reported. This report aims to elaborate clinical various manifestations of SS in a patient with a history of total knee arthroplasty. In addition, this report describes how to discriminate inflammation between SS and periprosthetic joint infection. Level of evidence V.

A Case of the Co-Existence of Subcorneal Pustular Dermatosis and Pyoderma Gangrenosum and a Review of the Literature

BACKGROUND:

Subcorneal pustular dermatosis, also known as Sneddon-Wilkinson disease, can be classified as one of the neutrophilic dermatoses together with pyoderma gangrenosum. The development of both SPD and PG in the same patient has rarely been reported and may be a strong indicator of IgA dysglobulinemia

CASE REPORT:

We report the case of a 34-year-old woman with a 2-year history of relapsing pustular eruptions mainly affecting the abdomen, gluteus region, elbows, and the extremities. Four years after the onset of subcorneal pustular dermatosis (SPD), she developed pyoderma gangrenosum (PG) on her right hand. In literature, the coexistence of SPD and PG in the same patient has already been described. This co-occurrence might indicate a certain predisposition for immune dysregulation.

CONCLUSION:

Although the two NDs are often associated with systemic diseases, these patients should be followed up for any malignancy because of the strong association between these disorders.

Function and regulation of IL-1α in inflammatory diseases and cancer

The interleukin (IL)-1 family of cytokines is currently comprised of 11 members that have pleiotropic functions in inflammation and cancer. IL-1α and IL-1β were the first members of the IL-1 family to be described, and both signal via the same receptor, IL-1R. Over the last decade, much progress has been made in our understanding of biogenesis of IL-1β and its functions in human diseases. Studies from our laboratory and others have highlighted the critical role of nod-like receptors (NLRs) and multi-protein complexes known as inflammasomes in the regulation of IL-1β maturation. Recent studies have increased our appreciation of the role played by IL-1α in inflammatory diseases and cancer. However, the mechanisms that regulate the production of IL-1α and its bioavailability are relatively understudied. In this review, we summarize the distinctive roles played by IL-1α in inflammatory diseases and cancer. We also discuss our current knowledge about the mechanisms that control IL-1α biogenesis and activity, and the major unanswered questions in its biology.

Neutrophil-mediated delivery of nanotherapeutics across blood vessel barrier

Nanotherapeutics, nanoparticles (NPs) loaded with drugs, show the ability of tissue targeting, long circulation and low toxicity compared with free drugs. Endothelium lying the lumen of a blood vessel is a barrier to restrain tissue deposition of nanotherapeutics. Neutrophils, a type of white blood cells, migrate across endothelium during inflammation. There is an emerging concept that in situ targeting of neutrophils allows delivery of nanotherapeutics into deep tissues at disease sites. Here we summarize the recent advances in delivery of nanotherapeutics to inflammatory tissues or tumor microenvironments via neutrophil infiltration. The studies would shift the current paradigm of nanomedicine to biology-driven design of nanotherapeutics. [Formula: see text].

Sweet syndrome in patients with and without malignancy: A retrospective analysis of 83 patients from a tertiary academic referral center

BACKGROUND

Sweet syndrome is a neutrophilic dermatosis that may be categorized into classic, malignancy-associated, and drug-induced subtypes. Few studies have systematically analyzed this rare disorder.

OBJECTIVE

To describe the clinicopathologic characteristics and treatment of Sweet syndrome and identify characteristics associated with concurrent malignancy.

METHODS

We retrospectively reviewed patients with Sweet syndrome at the University of Pennsylvania from 2005 to 2015.

RESULTS

We identified 83 patients (mean age, 57 years; 51% male) with Sweet syndrome: 30% with the classic form, 44% with the malignancy-associated form, 24% with the drug-induced form in the setting of malignancy, and 2% with the drug-induced form. Acute myeloid leukemia was the most common malignancy (in 24 of 83 patients [29%]). Filgrastim was the most common medication (used in 8 of 83 patients [10%]). Leukopenia (P < .001), anemia (P = .002), thrombocytopenia (P < .001), absence of arthralgia (P < .001), and histiocytoid or subcutaneous histopathology (P = .024) were associated with malignancy (χ² test).

LIMITATIONS

This was a retrospective study that represents patients from a single tertiary academic referral center, which may limit its generalizability to other settings.

CONCLUSION

When caring for patients with Sweet syndrome, dermatologists should be aware of the potential association of leukopenia, anemia, thrombocytopenia, absence of arthralgia, and histiocytoid or subcutaneous histopathology with malignancy.

Neutrophilic dermatoses: Kids are not just little people

Neutrophilic dermatoses are a group of inflammatory skin disorders characterized by an overactive innate immune system with dysregulation of neutrophils without underlying infectious etiology. The major representative conditions discussed are Sweet syndrome; pyoderma gangrenosum; neutrophilic eccrine hidradenitis; palmoplantar eccrine hidradenitis; subcorneal pustular dermatoses; bowel-associated dermatosis arthritis syndrome; and synovitis, acne, pustulosis, hyperostosis, and osteitis. We will also discuss other neutrophilic conditions present almost exclusively in the pediatric population, including congenital erosive and vesicular dermatosis with reticulated supple scarring and the recently described group of autoinflammatory diseases. The clinical characteristics, diagnostic approach, and treatment management in the pediatric and adult population are discussed.

T helper type 1-related molecules as well as interleukin-15 are hyperexpressed in the skin lesions of patients with pyoderma gangrenosum

Pyoderma gangrenosum (PG) is a rare, immune-mediated skin disease classified into the group of neutrophilic dermatoses. Although a number of studies confirmed the central role of innate immunity, only few studies have investigated the possible contributing role of acquired immunity. In particular, no reports concerning T helper type 1 (Th1) and Th2 cells are available as yet. Therefore, 15 patients with PG, five with Sweet's syndrome (SS) and nine skin specimens from healthy controls (HC) were investigated, evaluating the expression of Th1-related markers interleukin (IL)-12, interferon (IFN)-γ, C-X-C motif chemokine receptor 3 (CXCR3) and C-C motif chemokine receptor 5 (CCR5), of the Th2-related molecules IL-4, IL-5, IL-13 and CCR3, of the co-stimulatory axis CD40/CD40 ligand, of IL-15 and the natural killer (NK) cell marker CD56 in skin lesions by immunohistochemistry. Patients with PG and SS showed a higher expression of Th1 markers than HC. Conversely, IL-5- and CCR3-expressing cells were less numerous in PG skin lesions compared to SS (P = 0·0157 and < 0·0001, respectively). Both CD40 and CD40L were expressed more in PG than in SS and HC (P < 0·0001 for both). Finally, the number of IL-15⁺ and CD56⁺ cells was higher in the skin of patients with PG than in those of SS and HC (P < 0·0001 for both). Our results suggest that Th2 cells are down-regulated in PG. At the same time, over-expression of the co-stimulatory axis CD40/CD40L amplifies the impairment of the Th1/Th2 balance. Both these findings might explain the most aggressive behaviour of PG in comparison to SS. Moreover, over-expression of IL-15⁺ and CD56⁺ cells may suggest a possible role of NK cells in the pathogenesis of the disease.