Pustular Panniculitis in Rheumatoid Arthritis

Neutrophilic Infiltrates in Panniculitis: Comprehensive Review and Diagnostic Algorithm Proposal

Neutrophilic infiltrates in panniculitis can be seen in different clinical-pathological entities. There are a "mostly neutrophilic inflammatory infiltrate" in some entities classically defined as neutrophilic panniculitis and already included in algorithms, such as enzymatic panniculitis, infective and factitial ones, erythema induratum, or subcutaneous Sweet syndrome, but there are also other panniculitis where neutrophils are frequently observed such as panniculitis associated with inflammatory bowel disease or rheumatoid arthritis, or drug-induced panniculitis associated with BRAF inhibitors, and finally, some panniculitis are better classified in other panniculitides groups but may present with neutrophil-rich variants, such as the neutrophil-rich subcutaneous fat necrosis of the newborn. We review the main clinical and histopathological features of most of these panniculitides and construct a diagnostic algorithm including these diseases.

Neutrophilic panniculitis: algorithmic approach to a heterogeneous group of disorders

CONTEXT

Neutrophilic panniculitis encompasses an etiologically and morphologically heterogeneous group of disorders. Correct histopathologic diagnosis is important in identifying certain systemic diseases and guiding appropriate treatment.

OBJECTIVE

To review the clinical and histopathologic features of different types of neutrophilic panniculitis, and to provide a diagnostic algorithm for these disorders.

DATA SOURCES

A review of the literature with emphasis on the distinguishing features of different entities was performed.

CONCLUSIONS

Evaluation for neutrophilic panniculitis entails paying close attention to the pattern of inflammation, the type of fat necrosis present, any evidence of vascular damage, and other relevant histopathologic features. An algorithmic approach integrating all histopathologic, clinical, and laboratory findings is required for correct diagnosis.

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.

Panniculitis: an unusual cutaneous manifestation of rheumatoid arthritis

Specific and nonspecific panniculitis may occur during the course of connective tissue diseases. However, association of panniculitis and rheumatoid arthritis has only rarely been described, and with so few reports, it is difficult to know the significance of this unusual association. We describe 2 patients with rheumatoid arthritis and features of Sjögren syndrome in whom panniculitis developed during the course of the disease. Histologic confirmation of septal panniculitis was established in one case and the panniculitis in this case improved as the arthritis resolved.

Sweet's syndrome revisited: a review of disease concepts

Sweet's syndrome, also referred to as acute febrile neutrophilic dermatosis, is characterized by a constellation of symptoms and findings: fever, neutrophilia, erythematous and tender skin lesions that typically show an upper dermal infiltrate of mature neutrophils, and prompt improvement of both symptoms and lesions after the initiation of treatment with systemic corticosteroids. Hundreds of patients with this dermatosis have been reported. The manifestations of Sweet's syndrome in these individuals have not only confirmed those originally described by Dr Robert Douglas Sweet in 1964, but have also introduced new features that have expanded the clinical and pathologic concepts of this condition. The history, clinical characteristics, laboratory findings, associated diseases, pathology, and treatment options of Sweet's syndrome are reviewed. The evolving and new concepts of this dermatosis that are discussed include: (i) Sweet's syndrome occurring in the clinical setting of a disease-related malignancy, or medication, or both; (ii) detection of additional sites of extracutaneous Sweet's syndrome manifestations; (iii) discovery of additional Sweet's syndrome-associated diseases; (iv) variability of the composition and/or location of the cutaneous inflammatory infiltrate in Sweet's syndrome lesions; and (v) additional efficacious treatments for Sweet's syndrome.

Panniculitis. Part II. Mostly lobular panniculitis

The second part of our review of panniculitis summarizes the clinicopathologic features of the mostly lobular panniculitides. Erythema induratum of Bazin (nodular vasculitis) represents the most common variant of lobular panniculitis with vasculitis, although controversy persists about the nature of the involved vessels. Mostly lobular panniculitides without vasculitis comprise a series of disparate disorders. These include sclerosing panniculitis that results from chronic venous insufficiency of the lower extremities; panniculitis with calcification of the vessel walls such as calciphylaxis and oxalosis; and inflammatory diseases with crystals within the adipocytes such as sclerema neonatorum, subcutaneous fat necrosis of the newborn, and poststeroid panniculitis. Connective tissue diseases, such as systemic lupus erythematosus and dermatomyositis, pancreatic diseases, and alpha(1)-antitrypsin deficiency may also show a mostly lobular panniculitis with characteristic histopathologic features. Lobular panniculitis may also be an expression of infections, trauma, or factitial causes involving the subcutaneous fat. Lipoatrophy refers to a loss of subcutaneous fat due to a previous inflammatory process involving the subcutis, and it may be the late-stage lesion of several types of panniculitis. In contrast, lipodystrophy means an absence of subcutaneous fat with no evidence of inflammation and often the process is associated with endocrinologic, metabolic, or autoimmune diseases. Finally, cytophagic histiocytic panniculitis is the term that has been used to describe two different processes: one is inflammatory, a lobular panniculitis, and the other one is neoplastic, a subcutaneous T-cell lymphoma. The only common feature of these two different processes is the presence of cytophagocytosis in the lesions. (J Am Acad Dermatol 2001;45:325-61.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with the pathogenesis, clinical manifestations, histopathologic findings, and treatment options for the most frequent variants of the lobular panniculitides.