Acute febrile neutrophilic dermatosis (Sweet’s syndrome). Curr Opin Hematol. 2013;20:26-35. [PMID: 23207661 DOI: 10.1097/moh.0b013e32835ad132]

Drug-induced Sweet's syndrome: A case/non-case study in the French pharmacovigilance database

AIMS

Sweet's syndrome is an acute febrile neutrophilic dermatosis first described in 1964 by Robert Douglas Sweet. The pathophysiological mechanism is not fully established; however, several cases of Sweet's syndrome have been reported following drug administration.

METHODS

To investigate the existence of pharmacovigilance signals between drugs and the occurrence of Sweet's syndrome, we performed a case/non-case study on reports of 'acute febrile neutrophilic dermatosis' registered in the French pharmacovigilance database. Reporting odds ratio (ROR) with its 95% confidence interval were calculated.

RESULTS

Amongthe 994 789 reports recorded in the database, 136 were Sweet's syndrome, of which 50.7% were men and the median age was 59 years (range 15-91). A total of 224 drugs were mentioned as suspects: 21.0% were antibacterials, 19.2% were antineoplastics and 12.1% were immunosuppressants. Median time to onset from drug initiation to the development of Sweet's syndrome was 15 days (range 1-1095). The highest RORs were observed with bortezomib (74.04 [40.8-134.2]), azacitidine (72.14 [29.4-176.9]), perfilgrastim (67.05 [21.2-211.6]), azathioprine (55.46 [34.8-88.4]) and bendamustine (35.84 [11.4-112.8]).

CONCLUSIONS

Pharmacovigilance signals have been observed between the occurrence of Sweet's syndrome and colony-stimulating factors, immunosuppressants, antineoplastics and antibiotics. Clinicians should be aware of the potential associations with these drugs and should be encouraged to report any case of drug-induced Sweet's syndrome.

Neutrophilic Dermatoses Associated with Myeloid Malignancies

Neutrophilic dermatoses (ND) are a group of conditions characterized by an aseptic accumulation of polymorphonuclear leukocytes in the skin. Occurrence of ND in association with myeloid malignancies, mainly myelodysplastic syndrome and myelogenous acute leukemia, is not rare and is often associated with a poor prognosis. Recent findings have improved understanding of the pathophysiology of myeloid malignancy-associated ND. We review the clinical spectrum of myeloid malignancy-associated ND with an emphasis on recently identified mechanisms. Myeloid leukemia cells retain the potential for terminal differentiation into polymorphonuclear leukocytes in the skin. Many studies suggest a clonal link between myeloid malignancies and ND. Activation of autoinflammatory pathways (NOD-like receptor family pyrin domain-containing-3, Familial Mediterranean Fever Gene) in the clonal cells of myeloid disorders may also be involved in this setting.

Idiopathic, Refractory Sweet's Syndrome Associated with Common Variable Immunodeficiency: a Case Report and Literature Review

PURPOSE OF REVIEW

Sweet's syndrome (SS) is classically considered a hypersensitivity reaction often associated with autoimmune disorders and malignancy. SS has also been increasingly reported to occur with immunodeficiencies. We present a case of treatment-refractory, systemic SS as the initial manifestation in a young child with common variable immunodeficiency (CVID). We also review current literature about SS and concurrent immunodeficiencies and autoimmunity in CVID patients.

RECENT FINDINGS

Few case reports exist regarding the co-occurrence of Sweet's syndrome and primary immunodeficiencies. SS is characterized by a pro-inflammatory state with a neutrophil predominance resulting in a spectrum of clinical manifestations. CVID is a multifactorial antibody deficiency that can be associated with autoimmunity, which some studies have proposed to be secondary to altered CD21 expression. SS occurring in patients with CVID has been infrequently reported, and one case study demonstrated improvement of Sweet's associated skin lesions with immunoglobulin replacement. In our case, the patient had multi-system SS refractory to multiple immunomodulatory therapies. To our knowledge, this is the first report of the effective and safe use of intravenous tocilizumab and oral lenalidomide to treat SS in a child with CVID. Immunoglobulin replacement reduced the frequency of infections and may have contributed to the opportunity to wean the immunosuppressive therapies for Sweet's syndrome. Sweet's syndrome as an initial manifestation of co-occurring immunodeficiencies is rare, and providers need a high index of suspicion. In addition, treatment of SS associated with an immunodeficiency can be a challenge. Treatment with immunoglobulin replacement reduces the frequency of infections, and in some patients with concurrent SS may improve skin lesions and reduce the need for immunomodulator therapy. Further study is necessary to better understand the pathogenesis of CVID in patients with SS and to identify possible biomarkers that predict who with SS are at risk for developing hypogammaglobulinemia.

Sweet’s Syndrome: A Classical Presentation of a Rare Disease

Sweet’s syndrome, also known as acute febrile neutrophilic dermatosis, is a rare disorder that typically presents with rapid appearance of tender skin lesions accompanied by fever and leukocytosis with neutrophilia. Its pathogenesis is not fully understood. The syndrome is generally classified into classical, malignancy-associated, and drug-induced categories, each of which has its specific characteristics. In this article, we present a case of classical Sweet’s syndrome in a woman who presented with an acute viral illness.

Treatment of Sweet's syndrome in pregnancy

Pregnancy-associated Sweet's syndrome is a rare occurrence (2%), with good prognosis, spontaneous resolution after delivery, and not increased infant morbidity and mortality. However, differential diagnosis is not easy for physician not familiar with skin lesions. Systemic involvement, even though unusual, might occur in nearly every organ of the body, including pericardium, myocardium, and placenta, as well as one report of early fetal miscarriage, questioning the possibility of risks underestimation. We present two further cases, one occurred in a 31-year-old woman at 26 weeks of gestation and the other on a 26-year-old woman at 24 weeks of gestation, primigravidae. Both presented with tender papules and nodules on their face and upper body parts. Laboratory examinations and skin biopsy histology were pathognomonic. Monitoring of general maternal and fetal conditions showed no signs of sufferance, but the decision to accelerate skin symptoms release, being time to delivery quite distant, challenge the treatment options. There are no recommended treatments for Sweet syndrome and the choice is very limited during pregnancy. A short course of oral steroids was very effective, with lesions healing in few days, no relapses or fetal complications. When pregnant patients exhibit fever, neutrophilia, arthralgia or myalgia, and tender erythematous plaques or nodules, Sweet syndrome should be considered. The trained dermatologist is in the leading position to address the differential diagnosis, reassure the patient, and avoid complications, even if they are rare.

Clonal neutrophil infiltrates in concurrent Sweet's syndrome and acute myeloid leukemia: A case report and literature review

Sweet's syndrome (SS), also known as acute febrile neutrophilic dermatosis is often associated with a hematological malignancy, especially acute myeloid leukemia (AML) and myeloid dysplasia syndrome. Histopathologically, SS is characterized by diffuse infiltrates in the upper dermis, predominantly consisting of mature neutrophils. The origin of neutrophils invading the skin remains unknown. Herein, we report a patient with concurrent acute monoblastic leukemia and SS who initially presented with discrete erythematous papules and nodules on the neck. Single nucleotide polymorphism (SNP) array and next generation sequencing (NGS) revealed a concordant fms-related tyrosine kinase-3 (FLT-3) gene mutation in the bone marrow and skin lesion, indicating that the neutrophilic infiltrates were clonally related to the underlying myeloid neoplasm. This is the first case report of concurrent SS and AML, in which SNP array and NGS analysis were applied to confirm the clonality of the neutrophilic infiltrates.

Diagnosis and Treatment of Rosacea Fulminans: A Comprehensive Review

Rosacea fulminans is a rare inflammatory condition of the central face marked by the abrupt onset of erythematous coalescing papules, pustules, nodules, and draining sinuses. Due to infrequent reporting in the literature, the pathophysiology, classification, and nomenclature of this condition remain controversial. This comprehensive review evaluated a total of 135 cases of rosacea fulminans for clinical and histopathologic features and reported treatment strategies. Patients were 91% female with an average age of onset of 31.3 years. Only 19% of cases reported duration of symptoms longer than 3 months, and reports of recurrence were uncommon. A majority of patients had history of rosacea or flushing, and common triggers included hormonal shifts, emotional stress, and medications. Extrafacial or systemic involvement was rare. Though oral and topical antibiotics were frequently utilized to treat rosacea fulminans, there was a clear shift in reported treatments for rosacea fulminans following the introduction of isotretinoin use in 1987, marked by increased reliance on isotretinoin in addition to topical and systemic corticosteroids. Newer treatments were associated with superior improvement compared with antibiotic monotherapy, most notably dramatically reduced rates of scarring, though reduced rates of disease recurrence were not evident. Several patterns revealed through this review reinforce the classification of rosacea fulminans as a severe yet distinct variant of rosacea and highlight key distinguishing clinical features and treatment options for optimal management.

Sweet's Syndrome (SS) in the Course of Acute Myeloid Leukaemia (AML)

Firstly described by Robert Douglas Sweet in 1964, febrile neutrophilic dermatosis is a disabling, not only cutaneous disorder, clinically characterised by fever and painful erythematous nodules, with a typical background of neutrophilia. Sweet’s syndrome (SS) is a chronic inflammatory reactive disorder of unknown cause and incompletely established pathogenesis, although an interplay between genetic and environmental factors, including infections, is likely to occur. A significant part of cases has been demonstrated to be linked with malignancies, especially in the hematologic setting. Because of the underlying disease and related therapeutic measures, SS may present atypical clinical course, whereas the response to treatment is strictly dependent on the concurrent hematologic disease. Herein we describe a case of a lady who had a refractory form of SS, resulted in a paraneoplastic cutaneous disease, and AML. Surprisingly, clinical remission of SS followed cytotoxic chemotherapy while hematologic disorder obtained a further complete response.

Histiocytoid Sweet Syndrome in a Child without Underlying Systemic Disease

Sweet syndrome (acute, febrile, neutrophilic dermatosis) is characterized by the acute onset of an eruption of painful nodules or erythematous or violaceous plaques on the limbs, face and neck. These symptoms are accompanied by fever. The diagnostic features include histopathological findings of dermal neutrophilic infiltration without leukocytoclastic vasculitis or peripheral blood leukocytosis. Sweet syndrome is associated with infection, malignancies, autoimmune disease, pregnancy, and drugs. Patients with Sweet syndrome demonstrate a complete and rapid response to systemic steroid administration. Recently, a distinct variant of Sweet syndrome was reported, termed “histiocytoid Sweet syndrome”, in which the infiltration of myeloperoxidase-positive histiocytoid mononuclear cells are observed (in contrast to the infiltration of neutrophils). The other clinical features are similar to those of classic Sweet syndrome. Pediatric Sweet syndrome is uncommon, and the histiocytoid type is even rarer. To date, four cases of histiocytoid Sweet syndrome have been reported in children. Herein, we describe a case of histiocytoid Sweet syndrome in an otherwise healthy 10-year-old boy with no underlying systemic disease in whom non-steroidal, anti-inflammatory drug treatment was successful.

Sweet syndrome presenting as a febrile rash in a returning traveller

Sweet syndrome was discovered in 1964 and is now well described in the dermatology literature. Knowledge of this unique febrile and painful dermatosis is important for the emergency physician because the syndrome can be readily identified and is extremely responsive to oral steroid therapy. Early diagnosis can greatly improve patient satisfaction and avoid days of ineffective treatment. An accurate and timely diagnosis of Sweet syndrome is also important to guide investigation into a number of associated diseases.

Sweet Syndrome: Clinical Features, Histopathology, and Associations of 83 Cases

BACKGROUND

Sweet syndrome (SS) is an infrequent skin disease characterised by sudden onset of fever, leukocytosis, neutrophilia, and tender erythematous plaques infiltrated by neutrophils. Multiple conditions have been associated with this syndrome.

OBJECTIVES

The aim of this study was to evaluate the clinical, epidemiological, laboratory, and histopathological findings and associations of patients with SS.

METHODS

We conducted a retrospective study of 83 patients with SS followed between January 1, 2006, and January 31, 2015.

RESULTS

Of the patients, 82% were female; the mean age at onset was 48 years. Clinical presentation was mainly characterised by erythematous and edematous plaques, mostly on upper extremities and trunk. Fever was observed in 32%; 60% presented leukocytosis and 39% neutrophilia. On histopathological examination, neutrophilic and lymphohistiocytic infiltrate and edema were the most frequent findings. Fourteen percent of patients had malignancy or hematologic disorders, 26% were classified as having drug-induced SS, and 24% noted recent infection. Only 2 cases occurred during pregnancy. Systemic corticosteroid was the most common choice of treatment, with excellent response. In malignancy-associated SS, the mean hemoglobin level was lower ( P = .01) and the erythrocyte sedimentation rate (ESR) was higher ( P = .04) in comparison to classic and drug-induced SS. Leukocytoclasia was associated with higher risk of recurrence ( P = .01).

CONCLUSION

All patients with SS deserve careful investigation of possible underlying conditions. Higher ESR and lower hemoglobin levels might reinforce the need of malignancy screening. Also, leukocytoclasia appears to be a potential marker of higher recurrence rate, demanding closer and longer follow-up.

Disorders characterized by predominant or exclusive dermal inflammation

Some cutaneous inflammatory disorders are typified by a predominant or exclusive localization in the dermis. They can be further subdivided by the principal cell types into lymphocytic, neutrophilic, and eosinophilic infiltrates, and mixtures of them are also seen in a proportion of cases. This review considers such conditions. Included among the lymphoid lesions are viral exanthems, pigmented purpuras, gyrate erythemas, polymorphous light eruption, lupus tumidus, and cutaneous lymphoid hyperplasia. Neutrophilic infiltrates are represented by infections, Sweet syndrome, pyoderma gangrenosum, and hidradenitis suppurativa, as well as a group of so-called "autoinflammatory" dermatitides comprising polymorphonuclear leukocytes. Eosinophil-dominated lesions include arthropod bite reactions, cutaneous parasitic infestations, the urticarial phase of bullous pemphigoid, Wells syndrome (eosinophilic cellulitis), hypereosinophilic syndrome, and Churg-Strauss disease. In other conditions, eosinophils are admixed with neutrophils in the corium, with or without small-vessel vasculitis. Exemplary disorders with those patterns include drug eruptions, chronic idiopathic urticaria, urticarial vasculitis, granuloma faciale, and Schnitzler syndrome (chronic urticarial with a monoclonal gammopathy).

Palisaded Granulomatous Dermatitis Associated with Ulcerative Colitis: A Comprehensive Literature Review

Palisaded granulomatous dermatitis is an uncommon pathologic condition potentially associated with several disorders. These include drugs, inflammatory bowel disease, multiple myelomas, rheumatoid arthritis, and systemic lupus erythematosus. An illustrative case of a man with palisaded granulomatous dermatitis who subsequently developed ulcerative colitis is described, and the characteristics of other individuals with ulcerative colitis-associated palisaded granulomatous dermatitis are reviewed. PubMed was used to search the following terms: palisaded, interstitial, granulomatous, dermatitis, ulcerative colitis, and neutrophilic. Papers were obtained and references were reviewed. Ulcerative colitis-associated palisaded granulomatous dermatitis is uncommon. Palisaded granulomatous dermatitis-associated ulcerative colitis has been reported in four individuals. The palisaded granulomatous dermatitis appeared from six years prior to diagnosis to 19 years following diagnosis of the patient’s gastrointestinal disease. In addition to individual and grouped papular lesions on the elbows, the morphology of palisaded granulomatous dermatitis can also present as indurated linear plaques overlying the metacarpophalangeal (MCP) joints and proximal fingers. 

Histiocytoid Sweet's syndrome in a patient with myelodsyplastic syndrome: report and review of the literature

The neutrophilic dermatoses are a group of disorders characterized by skin lesions for which histological examination reveals intense epidermal and/or dermal inflammatory infiltrates composed primarily of neutrophils without evidence of infection. The myelodysplastic syndromes consist of a heterogeneous group of malignant hematopoietic stem cell disorders characterized by dysplastic and inadequate blood cell production with a variable risk of transformation to acute leukemia. Rarely, histiocytoid Sweet's syndrome occurring in patients with myelodysplastic syndrome has been described. We present a case of a 66-year-old woman with a history of myelodysplastic syndrome who developed histiocytoid Sweet's syndrome. We also review the literature and characterize patients with myelodysplastic syndrome who have developed histiocytoid Sweet's syndrome.

Sweet's syndrome complicating ulcerative colitis: a rare association

Sweet's syndrome (SS) is a neutrophilic dermatosis disorder of unknown aetiology, characterised by acute fever, neutrophilia, painful erythematous papules, nodules and plaques, and an infiltrate consisting predominantly of mature neutrophils in the upper dermis. Classical SS is a rare extra-intestinal manifestation of inflammatory bowel disease (IBD). It is more common in Crohn's disease than in ulcerative colitis (UC). There is a predilection for women, and for patients with colonic disease and active IBD. We report the case of a 39-year-old woman with a flare of moderate severity UC treated with mesalazine who presented with a 5-day history of acute fever, painful papules and plaques on forearms and legs, episcleritis and cervical pain. Skin biopsies showed papillary dermis inflammatory cell infiltration composed mainly of neutrophils, without evidence of leukocytoclastic vasculitis or panniculitis, compatible with SS. The patient had an excellent response to systemic corticosteroids. Symptoms promptly improved and skin lesions resolved after 7 weeks.

GSK3 Deficiencies in Hematopoietic Stem Cells Initiate Pre-neoplastic State that Is Predictive of Clinical Outcomes of Human Acute Leukemia

Initial pathway alternations required for pathogenesis of human acute myeloid leukemia (AML) are poorly understood. Here we reveal that removal of glycogen synthase kinase-3α (GSK-3α) and GSK-3β dependency leads to aggressive AML. Although GSK-3α deletion alone has no effect, GSK-3β deletion in hematopoietic stem cells (HSCs) resulted in a pre-neoplastic state consistent with human myelodysplastic syndromes (MDSs). Transcriptome and functional studies reveal that each GSK-3β and GSK-3α uniquely contributes to AML by affecting Wnt/Akt/mTOR signaling and metabolism, respectively. The molecular signature of HSCs deleted for GSK-3β provided a prognostic tool for disease progression and survival of MDS patients. Our study reveals that GSK-3α- and GSK-3β-regulated pathways can be responsible for stepwise transition to MDS and subsequent AML, thereby providing potential therapeutic targets of disease evolution.

Inpatient Consultative Dermatology

Dermatology consultation can improve diagnostic accuracy in the hospitalized patient with cutaneous disease. Dermatology consultation can streamline and improve treatment plans, and potentially lead to cost savings. Dermatology consultants can be a valuable resource for education for trainees, patients, and families. Inpatient consultative dermatology spans a breadth of conditions, including inflammatory dermatoses,infectious processes, adverse medication reactions, and neoplastic disorders, many of which can be diagnosed based on dermatologic examination alone, but when necessary, bedside skin biopsies can contribute important diagnostic information.

Helicobacter pylori and inflammatory skin diseases

Throughout the history of mankind, infections have been the major cause of diseases. Over the last decades, not only the incidence of emerging infectious diseases have increased, but also tremendous strides have been made in understanding the biology of several pathogenic microorganisms. Helicobacter pylori (H. pylori) is a spiral-shaped, gram-negative bacterium, which infects over the half of the world’s population. H. pylori has been implicated in the pathogenesis of a number of gastrointestinal disorders. However, new researches have demonstrated that H. pylori is also involved in the pathogenesis of various extragastric diseases. The difference in the clinical outcome of H. pylori infection may be explained, at least in part, by host response to the infection and H. pylori virulence factors. It is obvious that as developments in the research on H. pylori spring up, an understanding of the pathophysiology of H. pylori infection will continue to be identified. Here in this review, we summarize the current knowledge about H. pylori and its association with inflammatory skin diseases.

Proton pump inhibitor-induced Sweet's syndrome: report of acute febrile neutrophilic dermatosis in a woman with recurrent breast cancer

Background:

Sweet’s syndrome, also referred to as acute febrile neutrophilic dermatosis, can either occur as an idiopathic disorder or associated with another condition, including cancer, or induced by exposure to a drug. Proton pump inhibitors selectively inhibit gastric parietal cell H+-K+-adenosine triphosphatase and are most commonly used for the treatment of gastroesophageal reflux disease.

Purpose:

Proton pump inhibitor-associated Sweet’s syndrome is described in a woman with recurrent breast cancer.

Methods:

PubMed was used to search the following terms, separately and in combination: acute febrile neutrophilic dermatosis, breast cancer, malignancy, paraneoplastic, proton pump inhibitor, and Sweet’s syndrome. All papers were reviewed and relevant manuscripts, along with their reference citations, were evaluated.

Results:

Proton pump inhibitors have previously been associated with cutaneous adverse reactions including maculopapular rash, subacute cutaneous lupus erythematosus and toxic epidermal necrolysis. However, drug-induced Sweet’s syndrome has not been observed in patients receiving proton pump inhibitors. The reported woman developed Sweet’s syndrome after initial exposure and subsequent repeat challenge to proton pump inhibitors; subsequent studies also observed recurrence of her breast cancer presenting as metastases to her stomach and bone.

Conclusions:

Drug-induced Sweet’s syndrome has most commonly been associated with granulocyte colony stimulating factor in oncology patients. Malignancy-associated Sweet’s syndrome has been observed in patients with solid tumors, including breast cancer. Confirmation of proton pump inhibitor-induced Sweet’s syndrome, by repeat challenge with another medication in the same class of drug, was observed in a woman with breast cancer; although the subsequent discovery of recurrent breast cancer presenting as gastric mucosa and vertebral metastases also raises the possibility of concurrent paraneoplastic Sweet’s syndrome, her Sweet’s syndrome symptoms and lesions resolved without recurrence while her recurrent metastatic visceral malignancy persisted. In summary, medication-associated Sweet’s syndrome can occur in oncology patients and proton pump inhibitors should be added to the list of medications associated with the potential to cause drug-induced Sweet’s syndrome.

Drug-induced skin reactions: a pathologist viewpoint

Cutaneous drug reactions are common adverse effects that occur in about 2-3% of the hospitalized patients. They have both immunologic and non-immunologic underlying mechanisms. These reactions are clinically and histologically similar to dermatoses. Their significant clinical indicators include: history of drug intake, atypical clinical features and improvement after cessation of the offending drugs. Their diagnostic histological clues include the presence of mixed histological patterns, apoptotic keratinocytes, eosinophils (dermis and epidermis), papillary dermal edema and extravasations of erythrocytes. However, no single clinical or histological feature is specific of drug eruptions. This work attempts to classify the histomorphologic reactions to various drugs in defined categories for assistance in morphologic diagnosis.

Neutrophilic dermatosis of dorsal hands

Sweet's syndrome is characterized by erythematous tender nodules and plaques over face and extremities. Fever, leukocytosis with neutrophilia, and a neutrophilic infiltrate in the dermis are characteristic features. Neutrophilic dermatosis of dorsal hands is a rare localized variant of Sweet's syndrome occurring predominantly over dorsa of hands. Various degrees of vascular damage may be observed on histopathology of these lesions. Both Sweet's syndrome and its dorsal hand variant have been reported in association with malignancies, inflammatory bowel diseases, and drugs. We report a patient with neutrophilic dermatoses of dorsal hands associated with erythema nodosum. He showed an excellent response to corticosteroids and dapsone.

Multi-organ involvement of Sweet's syndrome: a case report and literature review

The hallmark of Sweet's syndrome (SS) is the infiltration of mature neutrophils in the upper dermis. We herein report a case of SS with multi-organ involvement. A 32-year-old man presented with fever, anemia and dyspnea. He was given antibiotics, without any improvements. Later, a number of erythematous lesions appeared, accompanied by deteriorating respiratory and cardiovascular functions. A diagnosis of SS was confirmed on a skin biopsy, and the patient was given corticosteroids, the dose of which was reduced after one month. The organ function subsequently deteriorated, and he ultimately died of multi-organ failure. Early recognition of SS with multi-organ involvement is important in patients with SS.

Characteristics of Sweet Syndrome in patients with acute myeloid leukemia

INTRODUCTION

Sweet syndrome (SS) is associated with hematologic malignancies including acute myeloid leukemia (AML).

PATIENTS AND METHODS

Records of patients with AML treated at our institution were reviewed to identify those with SS. Patient characteristics, laboratory values, and cytogenetic and molecular abnormalities were retrospectively reviewed.

RESULTS

We identified 21 of 2178 (1%) AML patients who demonstrated clinical signs and symptoms, and histological features consistent with SS. Eleven patients (52%) were classified as AML with myelodysplasia-related features and 3 patients had therapy-related AML. Three patients had received treatment with granulocyte colony stimulation factor, 1 patient liposomal all-trans-retinoic acid, and 2 patients received hypomethylating agents before development of SS. Cytogenetic analysis revealed diploid karyotype in 7 patients (33%); -5/del(5q) in 8 patients (38%): 3 patients had -5/del(5q) as the sole abnormality and 5 patients had -5/del(5q) as part of complex cytogenetics; and complex cytogenetics in 5 patients (24%). Gene mutations in FMS-related tyrosine kinase-3 (FLT3) gene were identified in 7 of 18 evaluable patients (39%), including FLT3-internal tandem duplication in 4 patients and FLT3-D835 tyrosine kinase domain mutation in 3 patients.

CONCLUSION

SS occurs in 1% of AML patients; -5/del(5q) karyotype, FLT3 mutations, and AML with myelodysplasia-related features were more frequent among patients with SS.

Neutrophilic dermatoses: an update

Neutrophilic dermatoses constitute a heterogeneous group of dermatologic diseases, which are unified by the predominance of neutrophils within the inflammatory infiltrate on histopathology. The aims of this review were to provide an update on the clinical and histologic presentation of the main neutrophilic dermatoses and to develop a guide for clinical practice. A structured literature search of PubMed, Medline, and Embase was performed, using the key words "neutrophilic disorders", "cutaneous small vessel vasculitis", "Sweet's syndrome", "bowel associated dermatosis arthritis syndrome", "Behcet's", "palisaded neutrophilic and granulomatous dermatosis", "rheumatoid neutrophilic dermatitis", and "pyoderma gangrenosum". Related articles were screened for key terms and were included if appropriate. This group contains a wide spectrum of unique disorders, each with its own histologic and clinical subtleties, making specific diagnosis of a given entity within the group diagnostically challenging. The fact that overlapping forms of neutrophilic dermatoses, which share features of multiple neutrophilic dermatoses, are not uncommon makes the diagnoses more challenging.

Sweet's syndrome in a patient with metastatic melanoma after ipilimumab therapy

Sweet's syndrome, a neutrophilic dermatosis, is a known paraneoplastic complication occurring with various malignancies. It has been infrequently reported in association with melanoma. Ipilimumab is an antibody against an inhibitory cytotoxic T-lymphocyte-associated antigen 4 receptor on T cells. It is associated with a range of immune-related toxicities. Sweet's syndrome in association with ipilimumab has been reported only briefly in the literature. However, neutrophilic infiltration has been seen in biopsies of patients with ipilimumab-associated enterocolitis. We report, in detail, the case of a woman with metastatic melanoma undergoing ipilimumab therapy. After the second cycle of immunotherapy, the patient presented with high-grade fever followed by a rash on her hands. No infectious etiology was elucidated after an extensive workup. Pathologic examination of the skin biopsy from the hands confirmed neutrophilic dermatosis. The patient was treated with systemic steroids achieving complete remission of the skin lesions. Physicians should be aware of Sweet's syndrome as a possible cutaneous side effect of ipilimumab therapy and be familiar with its management.

SHP-1 and IL-1α conspire to provoke neutrophilic dermatoses

Neutrophilic dermatoses are a spectrum of autoinflammatory skin disorders that are characterized by extensive infiltration of neutrophils into the epidermis and dermis. The underlining biological pathways that are responsible for this heterogeneous group of cutaneous diseases have remained elusive. However, recent work from our laboratory and other groups has shown that missense mutations in Ptpn6, which encodes for the non-receptor protein tyrosine phosphatase Src homology region 2 (SH2) domain-containing phosphatase-1 (SHP-1), results in a skin disease with many of the major histopathological and clinical features that encompass neutrophilic dermatoses in humans. In particular, we found that loss-of-function mutation in Ptpn6 results in unremitting footpad swelling, suppurative inflammation, and neutrophilia. Dysregulated wound healing responses were discovered to contribute to chronic inflammatory skin disease in SHP-1 defective mice and genetic abrogation of interleukin-1 receptor (IL-1R) protected mice from cutaneous inflammation, suggesting that IL-1-mediated events potentiate disease. Surprisingly, inflammasome activation and IL-1β-mediated events were dispensable for Ptpn6^spin-mediated footpad disease. Instead, RIP1-mediated regulation of IL-1α was identified to be the major driver of inflammation and tissue damage.

Sweet syndrome: clinical presentation, associations, and response to treatment in 77 patients

BACKGROUND

Sweet syndrome is a neutrophilic dermatosis with cutaneous tender lesions that can be associated with malignancies, infections, systemic inflammatory disorders, and medications. Although numerous studies have described Sweet syndrome, few studies have systematically investigated Sweet syndrome.

OBJECTIVE

We sought to describe characteristics and treatments of patients with Sweet syndrome and evaluate clinical differences depending on the underlying cause.

METHODS

A retrospective study was conducted to identify patients with Sweet syndrome evaluated at Mayo Clinic from 1992 to 2010.

RESULTS

Of 77 patients with Sweet syndrome (mean age of onset 57 years), 43 (56%) were male. Eighteen patients (23%) reported a preceding infection. A total of 41 (53%) patients were classified as having classic Sweet syndrome, 27 (35%) patients had malignancy-associated Sweet syndrome, and in 9 (12%) patients drug-induced Sweet syndrome was considered. In all, 21 patients had a hematologic malignancy or myeloproliferative/myelodysplastic disorder, whereas 6 patients had solid tumors. The mean hemoglobin level, in both male and female patients (P < .0443 and P < .0035, respectively), was significantly lower in malignancy-associated versus classic and drug-induced Sweet syndrome. Systemic corticosteroids were the most frequently used treatment (70%).

LIMITATIONS

This is a retrospective study and represents patients from a single academic center.

CONCLUSIONS

Sweet syndrome is a distinctive disorder with certain clinical and histologic characteristics, which usually has a complete response to systemic corticosteroids. It is important to evaluate Sweet syndrome patients who have laboratory evidence of anemia for an underlying malignancy.