Sweet's syndrome as an initial presentation in systemic lupus erythematosus: a case report and review of the literature

Sweet Syndrome: Clinical Presentation, Malignancy Association, Autoinflammatory Disorders and Treatment Response in a Cohort of 93 Patients with Long-term Follow-up

Sweet syndrome is a neutrophilic dermatosis associated with multiple disorders. This retrospective case-series study of patients with Sweet syndrome in a tertiary hospital in Spain from 2001 to 2021, explores clinicopathological characteristics of Sweet syndrome and variables associated with malignancy, presence of autoinflammatory disorders and differences between histological subtypes. A total of 93 patients were identified: 30% idiopathic, 34% malignancy-associated, 29% reactive to infections or drug-associated, and 6% with an autoimmune/inflammatory condition. Acute myeloid leukaemia was the most common malignancy (16/93) followed by myelodysplastic syndrome (7/93). Patients with acute myeloid leukaemia presented isolated flares, marked cytopaenia and rapid response to treatment, whereas myelodysplastic syndrome followed a chronic-recurrent course. The most frequent associated medications and inflammatory  disorders were filgrastim and hydroxyurea (n = 2);  and inflammatory bowel disease (n = 4). In addition, 3 patients were diagnosed with VEXAS syndrome. Male sex (p = 0.006), fever (p = 0.034), increased erythrocyte sedimentation rate (p < 0.001), anaemia (p < 0.001), and thrombocytopaenia (p < 0.001) were associated with malignancy. Histologically, patients were classified as classic (60%), histiocytoid (22.5%) or subcutaneous (15%), with pain (p = 0.011) and nodules (p < 0.001) being associated with subcutaneous-Sweet syndrome. Sweet syndrome in the context of cytopaenia should alert the presence of malignancy. An  acquired autoinflammatory condition should be explored  in relapsing Sweet syndrome with myelodysplastic syndrome. A minimum follow-up of 6 months is recommended.

Insights Into the Pathogenesis of Sweet's Syndrome

Sweet's syndrome, also known as Acute Febrile Neutrophilic Dermatosis, is a rare inflammatory condition. It is considered to be the prototype disease of neutrophilic dermatoses, and presents with acute onset dermal neutrophilic lesions, leukocytosis, and pyrexia. Several variants have been described both clinically and histopathologically. Classifications include classic Sweet's syndrome, malignancy associated, and drug induced. The cellular and molecular mechanisms involved in Sweet's syndrome have been difficult to elucidate due to the large variety of conditions leading to a common clinical presentation. The exact pathogenesis of Sweet's syndrome is unclear; however, new discoveries have shed light on the role of inflammatory signaling, disease induction, and relationship with malignancy. These findings include an improved understanding of inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic contributions. Continued investigations into effective treatments and targeted therapy will benefit patients and improve our molecular understanding of inflammatory diseases, including Sweet's syndrome.

Neutrophilic skin lesions in autoimmune connective tissue diseases: nine cases and a literature review

The pathophysiology of neutrophilic dermatoses (NDs) and autoimmune connective tissue diseases (AICTDs) is incompletely understood. The association between NDs and AICTDs is rare; recently, however, a distinctive subset of cutaneous lupus erythematosus (LE, the prototypical AICTD) with neutrophilic histological features has been proposed to be included in the spectrum of lupus. The aim of our study was to test the validity of such a classification. We conducted a monocentric retrospective study of 7028 AICTDs patients. Among these 7028 patients, a skin biopsy was performed in 932 cases with mainly neutrophilic infiltrate on histology in 9 cases. Combining our 9 cases and an exhaustive literature review, pyoderma gangrenosum, Sweet syndrome (n = 49), Sweet-like ND (n = 13), neutrophilic urticarial dermatosis (n = 6), palisaded neutrophilic granulomatous dermatitis (n = 12), and histiocytoid neutrophilic dermatitis (n = 2) were likely to occur both in AICTDs and autoinflammatory diseases. Other NDs were specifically encountered in AICTDs: bullous LE (n = 71), amicrobial pustulosis of the folds (n = 28), autoimmunity-related ND (n = 24), ND resembling erythema gyratum repens (n = 1), and neutrophilic annular erythema (n = 1). The improvement of AICTDS neutrophilic lesions under neutrophil targeting therapy suggests possible common physiopathological pathways between NDs and AICTDs.

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.

Erysipelas-like erythema of familial Mediterranean fever syndrome: a case report with emphasis on histopathologic diagnostic clues

We report histopathological findings in a case of familial Mediterranean fever (FMF) syndrome with an erysipelas-like erythema (ELE). ELE is the only pathognomic cutaneous manifestation of FMF. ELE is characterized by well-demarcated, tender, erythematous and infiltrated plaques recurring on the same site and resolving spontaneously within 48-72 h. FMF is a monogenic autoinflammatory syndrome highlighted by recurrent fever associated with polyserositis involving mainly the peritoneum, synovium and pleura. FMF results from a mutation of the MEFV gene, which encodes for pyrin, leading to Il-1β activation and promoting neutrophil migration into the dermis. Histopathological findings in our case showed a sparse superficial perivascular and interstitial lymphocytic infiltrate admixed with some neutrophils, no eosinophils and mild papillary dermal edema. Venules and lymphatics were dilated, though no vasculitis was identified. Neutrophils are the most common cutaneous marker of autoinflammation, and cutaneous manifestations of monogenic autoinflammatory syndromes are represented by the spectrum of aseptic neutrophilic dermatoses. Neutrophils in the presence of recurrent fever and in the correct clinical context of recurrent erysipelas in the same site are a diagnostic clue for FMF.

Association of Sweet's Syndrome and Systemic Lupus Erythematosus

Sweet's syndrome is an acute febrile neutrophilic dermatosis which usually presents as an idiopathic disorder but can also be drug induced, associated with hematopoetic malignancies and myelodysplastic disorders, and more, infrequently, observed in autoimmune disorders. Sweet's syndrome has been reported in three cases of neonatal lupus, three cases of hydralazine-induced lupus in adults, and in nine pediatric and adult systemic lupus erythematosus (SLE) patients. We describe three additional adult cases of Sweet's associated with SLE and provide a focused review on nondrug-induced, nonneonatal SLE and Sweet's. In two of three new cases, as in the majority of prior cases, the skin rash of Sweet's paralleled underlying SLE disease activity. The pathogenesis of Sweet's remains elusive, but evidence suggests that cytokine dysregulation may be central to the clinical and pathological changes in this condition, as well as in SLE. Further research is needed to define the exact relationship between the two conditions.

Overview of common, rare and atypical manifestations of cutaneous lupus erythematosus and histopathological correlates

The skin is the second most frequently affected organ system in lupus erythematosus. Although only very rarely life threatening--an example is lupus erythematosus-associated toxic epidermal necrolysis--skin disease contributes disproportionally to disease burden in terms of personal and psychosocial wellbeing, vocational disability, and hence in medical and social costs. Since several manifestations are closely associated with the presence and activity of systemic lupus erythematosus, prompt and accurate diagnosis of cutaneous lupus erythematosus is essential. This review aims to cover common, rare, and atypical manifestations of lupus erythematosus-associated skin disease with a detailed discussion of histopathological correlates. Cutaneous lupus erythematosus covers a wide morphological spectrum well beyond acute, subacute and chronic cutaneous lupus erythematosus, which are commonly classified as lupus-specific skin disease. Other uncommon or less well-known manifestations include lupus erythematosus tumidus, lupus profundus, chilblain lupus, mucosal lupus erythematosus, and bullous lupus erythematosus. Vascular manifestations include leukocytoclastic and urticarial vasculitis, livedoid vasculopathy and livedo reticularis/ racemosa. Finally, we discuss rare presentations such as lupus erythematosus-related erythema exsudativum multiforme (Rowell syndrome), Kikuchi-Fujimoto disease, extravascular necrotizing palisaded granulomatous dermatitis (Winkelmann granuloma), and neutrophilic urticarial dermatosis.

[Lupus erythematosus. Wide range of symptoms through clinical variation, associated diseases and imitators]

The typical clinical forms of cutaneous lupus erythematosus (LE) are the butterfly rash, acute, subacute and chronic cutaneous lupus, intermediate lupus (lupus tumidus), chilblain- and bullous lupus, lupus profundus, and ulcerating lesions on the mucous membrane. Besides the typical lupus forms, nonspecific skin lesions are also observed such as dermal mucinosis, acneiform skin lesions, different variants of livedo, necrotizing vasculitis with ulcers, purpura, urticaria vasculitis, neutrophilic dermatosis, hyperpigmentation, hair and nail changes as well as overlap syndromes with erythema multiforme, scleroderma, Sjögren syndrome, Raynaud phenomenon, lichen planus, bullous pemphigoid und psoriasis. There are lupus imitators which create differential diagnostic challenges, such as infections with atypical mycobacteria or subcutaneous T-cell lymphoma both of which are similar to lupus profundus. All these skin lesions can present as maximal pathological findings seen in lupus or be caused by a variety of pathological laboratory findings such as the anti-phospholipid antibodies or a deficiency of complement factors. In the latter situation severe lupus often with complications can be expected.

Nonbullous neutrophilic dermatosis: Sweet's syndrome, neonatal lupus erythematosus, or both?

We describe a 5-day-old infant who fulfilled the diagnostic criteria for Sweet's syndrome, and the concurrent histologic and autoantibody features supporting the diagnosis of neonatal lupus. To our knowledge, this is the youngest case of Sweet's syndrome reported in the literature. Importantly, our findings further support the hypothesis that lupus erythematosus should be considered in the differential diagnosis of a nonbullous neutrophilic dermatosis, as it may represent the initial manifestation of the disease.

Neutrophilic urticarial dermatosis: a variant of neutrophilic urticaria strongly associated with systemic disease. Report of 9 new cases and review of the literature

We conducted the current study to define within the spectrum of the neutrophilic dermatoses a group of patients with an urticarial rash clinically and a neutrophilic dermatosis histopathologically. We reviewed the literature on neutrophilic urticaria and we report here a series of patients with this unique presentation. We reviewed all cutaneous biopsies submitted to our department between 2000 and 2006 in which histopathologic evaluation was compatible with this entity. We then retrieved the patient medical records and obtained information about follow-up and associated diseases. This allowed us to identify 9 patients with an urticarial eruption that was characterized histopathologically by a perivascular and interstitial neutrophilic infiltrate with intense leukocytoclasia but without vasculitis and without dermal edema. Four patients also had small foci of necrobiotic collagen bundles. The eruption consisted of pale, flat or only slightly raised, nonpruritic macules, papules, or plaques. Elementary lesions resolved within 24 hours. Purpura, angioedema, and facial swelling were not seen, but dermographism was present in 1 patient. Six patients had fever, 7 had polyarthritis, and 6 had leukocytosis. Seven patients had associated systemic diseases: adult-onset Still disease (3 patients), systemic lupus erythematosus (3 patients), and Schnitzler syndrome (1 patient).A similar rash has been reported previously in the literature, mostly in patients with systemic inflammatory diseases, but the majority of patients reported under the undefined designation of "neutrophilic urticaria" did have a different clinicopathologic presentation. Thus, we suggest naming this eruption "neutrophilic urticarial dermatosis," to emphasize that this entity expands the broad group of cutaneous manifestations of neutrophilic aseptic disease. This entity bears important medical significance as it is strongly indicative of an associated systemic disease, mainly Schnitzler syndrome, adult-onset Still disease, lupus erythematosus, and the hereditary autoinflammatory fever syndromes.

Sweet's syndrome--a comprehensive review of an acute febrile neutrophilic dermatosis

Sweet's syndrome (the eponym for acute febrile neutrophilic dermatosis) is characterized by a constellation of clinical symptoms, physical features, and pathologic findings which include fever, neutrophilia, tender erythematous skin lesions (papules, nodules, and plaques), and a diffuse infiltrate consisting predominantly of mature neutrophils that are typically located in the upper dermis. Several hundreds cases of Sweet's syndrome have been published. Sweet's syndrome presents in three clinical settings: classical (or idiopathic), malignancy-associated, and drug-induced. Classical Sweet's syndrome (CSS) usually presents in women between the age of 30 to 50 years, it is often preceded by an upper respiratory tract infection and may be associated with inflammatory bowel disease and pregnancy. Approximately one-third of patients with CSS experience recurrence of the dermatosis. The malignancy-associated Sweet's syndrome (MASS) can occur as a paraneoplastic syndrome in patients with an established cancer or individuals whose Sweet's syndrome-related hematologic dyscrasia or solid tumor was previously undiscovered; MASS is most commonly related to acute myelogenous leukemia. The dermatosis can precede, follow, or appear concurrent with the diagnosis of the patient's cancer. Hence, MASS can be the cutaneous harbinger of either an undiagnosed visceral malignancy in a previously cancer-free individual or an unsuspected cancer recurrence in an oncology patient. Drug-induced Sweet's syndrome (DISS) most commonly occurs in patients who have been treated with granulocyte-colony stimulating factor, however, other medications may also be associated with DISS. The pathogenesis of Sweet's syndrome may be multifactorial and still remains to be definitively established. Clinical and laboratory evidence suggests that cytokines have an etiologic role. Systemic corticosteroids are the therapeutic gold standard for Sweet's syndrome. After initiation of treatment with systemic corticosteroids, there is a prompt response consisting of dramatic improvement of both the dermatosis-related symptoms and skin lesions. Topical application of high potency corticosteroids or intralesional corticosteroids may be efficacious for treating localized lesions. Other first-line oral systemic agents are potassium iodide and colchicine. Second-line oral systemic agents include indomethacin, clofazimine, cyclosporine, and dapsone. The symptoms and lesions of Sweet's syndrome may resolved spontaneously, without any therapeutic intervention; however, recurrence may follow either spontaneous remission or therapy-induced clinical resolution.

Neutrophilic dermatoses

Neutrophils may infiltrate all layers of the skin and consequently may cause different disorders, each with its own characteristic clinical and laboratory findings. We discuss how these disorders present and how they are diagnosed and treated. In addition, important associations with internal diseases are discussed to assist clinicians in evaluating for a concurrent illness. Because treatment of these disorders may often require systemic therapy, the potential short-term and long-term effects of commonly used medications are discussed. Finally, treatment of recalcitrant diseases, mostly by use of therapies published in the form of small case series or reports, is also included to guide clinicians in dealing with the more challenging cases.