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This interesting skin rash was first described by Robert Douglas Sweet in 1964 as Acute Febrile Neutrophilic Dermatosis. Ever since his description, the disease has been referred to his name. As it was first described, the classic symptoms consist of an acute onset of erythematous plaques, nodules, and occasionally pustules, assymetrically distributed over the face, neck, and extremities. This eruption is often accompanied with fever and a neutrophilic leukocytosis. The rash may last from 1 week to several years.

The importance of correctly identifying this disease lies in its association with other diseases. An overview of some of these diseases is presented in the outline below. Some investigators have preferred the term Neutrophilic dermatosis of myeloproliferative disorders when this disease is associated with myeloproliferative disorders.


Disease Associations  
Laboratory/Radiologic/Other Diagnostic Testing  
Gross Appearance and Clinical Variants  
Histopathological Features and Variants  
Special Stains/
Electron Microscopy
Differential Diagnosis  
Commonly Used Terms  
Internet Links  

SYNONYMS Acute febrile neutrophilic dermatosis
Sweet's disease
AGE RANGE-MEDIAN Mid to late 50's
Females predominate


DRUGS All trans-retinoic acid
H ydralazine
Oral contraceptives


Relapsing polychondritis
Rheumatoid Arthritis
Non-specific connective disease
Inflammatory Bowel Disease


V iral pneumonia
Yersina infection
Helicobacter pylori infection



Hematologic malignancy most common with acute myelogenous leukemia and myelodysplasia the most frequent
Wide variety of solid tumors
No female predominance
More often pustular/bullous
More localized to face/upper body

All presented 1st or 2nd trimester
Most resolved spontaneously
No fetal morbidity or mortality
A Case of Sweet Syndrome Associated With Human Granulocytic Anaplasmosis

Charles L. G. Halasz, MD; G. William Niedt, MD; Caroline P. Kurtz, MD; Diana G. Scorpio, DVM,
; Johan S. Bakken, MD,
; J. Stephen Dumler, MD

Arch Dermatol. 2005;141:887-889. Abstract quote

Background  Acute febrile neutrophilic dermatosis, or Sweet syndrome (SS), is a condition that is presumed to be triggered by infectious disease agents. We report a case of SS associated with human granulocytic anaplasmosis (HGA), which is of interest because Anaplasma phagocytophilum infects, multiplies in, and disrupts the function of neutrophils, the key infiltrating cell in SS.

Observations  A patient with initial dermatologic manifestations of SS who did not respond to standard SS treatment was suspected to have concurrent HGA with the demonstration of leukopenia, thrombocytopenia, and elevated hepatic transaminase levels. The HGA diagnosis was established when morulae in neutrophils were observed on a peripheral blood smear, a finding confirmed by both serologic examination and polymerase chain reaction on the skin biopsy specimen used to establish the SS diagnosis.

Conclusion  The significant involvement of neutrophils with both SS and HGA warrants a broader search for additional cases that may further define whether pathogenetic linkages could exist.


Celecoxib-induced Sweet's syndrome

Kenneth H. Fye, etal.

San Francisco, California

J Am Acad Dermatol 2001;45:300-2. Abstract quote

Sweet's syndrome and related neutrophilic dermatoses have been associated with a variety of medications. Celecoxib is a new cyclo-oxygenase-2 inhibitor recently approved for arthritis.

We describe a 57-year-old man who experienced tender pustulopapular lesions on the dorsal aspects of the hands, neck, and legs 1 week after starting celecoxib.

Histopathologic examination of the lesion showed a diffuse dermal neutrophilic infiltrate, edema of the papillary dermis, spongiform pustules, and no leukocytoclastic vasculitis. These findings were consistent with Sweet's syndrome. Without realizing a possible association, the patient rechallenged himself with a second course of the medication, which resulted in a rapid exacerbation of his lesions. After discontinuing the medication for the second time, the patient has had complete clearing of his lesions.

To our knowledge, this is the first report of Sweet's syndrome associated with this new class of nonsteroidal anti-inflammatory drugs.


Sweet's syndrome and Chlamydia pneumoniae infection

Pietro Rubegni, etal.

J Am Acad Dermatol 2001;44:862-4 Abstract quote

We report the case of a patient in whom Sweet's syndrome developed during pneumonia caused by Chlamydia pneumoniae. Increased expression of helper T-cell type 1 cytokine secretion pattern in peripheral blood has recently been observed in patients with this syndrome, and chlamydia infection is known to primarily activate a helper T-cell type 1 immunologic response.

Sweet Syndrome (Acute Febrile Neutrophilic Dermatosis) Associated With Pulmonary Coccidioidomycosis

David J. DiCaudo, MD; Karel Jill Ortiz, MD; Stephanie J. Mengden, MD; Katherine K. Lim, MD


Arch Dermatol. 2005;141:881-884. Abstract quote

Background  Sweet syndrome (acute febrile neutrophilic dermatosis) may arise in association with a variety of underlying systemic diseases. Only 1 case of coccidioidomycosis-associated Sweet syndrome has previously been reported.

Observations  We describe 2 patients who developed Sweet syndrome during the onset of acute pulmonary coccidioidomycosis. Systemic antifungal therapy was given in both cases. Respiratory symptoms and skin lesions resolved within 5 weeks.

Conclusions  Sweet syndrome may be a presenting feature of coccidioidomycosis. Recognition of the underlying pulmonary infection is important so that inappropriate treatment with systemic corticosteroids can be avoided.


A case of Sweet's syndrome developed after the treatment of herpes simplex infection in a metastatic breast cancer patient.

Coskun U, Gunel N, Senol E, Ilter N, Dursun A, Tuzun D

J Cutan Pathol 2002 May;29(5):301-4 Abstract quote

Background: Sweet's syndrome or acute febrile neutrophilic dermatosis is associated with several systemic diseases such as malignancies and infectious diseases.

Methods: We present a 34-year-old woman with Sweet's syndrome associated with both herpes infection and metastatic disease.

Results: Skin biopsy showed neutrophilic infiltrates in the dermis confirming the diagnosis of Sweet's syndrome.

Conclusions: To our knowledge, this is the second case of Sweet's syndrome associated with herpes simplex infection in the literature. Further observations are required to determine the relationship between Sweet's syndrome and herpetic infection.


Sweet syndrome in multiple myeloma: a series of six cases.

Bayer-Garner IB, Cottler-Fox M, Smoller BR.

Department of Pathology, Baylor Medical College, Houston, TX, USA;Departments of Pathology and Dermatology and Myeloma Institute for Research and Therapy, University of Arkansas for Medical Sciences, AR, USA.

J Cutan Pathol 2003 Apr;30(4):261-4 Abstract quote

BACKGROUND: Sweet syndrome (SS), a paraneoplastic syndrome characterized by fever, neutrophilia, multiple erythematous painful plaques, and a dense dermal neutrophilic infiltration, has a known association with hematologic malignancies such as acute myelogenous leukemia. However, no clear association with multiple myeloma (MM) has been reported.

MATERIALS AND METHODS: Pathology reports of the 2357 patients with multiple myeloma at the University of Arkansas for Medical Sciences were reviewed to retrieve cases who had developed SS. Cytogenetic studies and immunoglobulin secretory status were retrieved. Five cases of SS in MM and 25 cases of SS in patients without MM underwent syndecan-1 immunohistochemistry.

OBSERVATIONS: Six cases of SS occurring in the setting of MM showed a predominance in patients secreting IgG paraprotein. Five of the six patients received granulocyte-colony stimulating factor while the sixth received granulocyte-monocyte-colony stimulating factor. Fifty percent showed a non-specific cytogenetic anomaly.

CONCLUSIONS: There is no specific cytogenetic anomaly associated with SS in the setting of MM. This paraneoplastic syndrome may be secondary to elevated levels of granulocyte colony stimulating factor (G-CSF), possibly with a component of enhanced sensitivity to endogenous G-CSF. The immunoglobulin secretory status parallels that seen in MM with cutaneous involvement, but IgG secretors may be at an increased risk of developing SS compared with their counterparts who secrete other immunoglobulins.


Acute febrile neutrophilic dermatosis following tuberculous infection.

Singh RK.

Physician District Hospital, Daltonganj, Jharkhand, India

J Assoc Physicians India 2002 Oct;50:1322-3 Abstract quote

A case of acute febrile neutrophilic dermatosis (Sweet's syndrome) in association with tuberculosis has been reported. However association of the two diseases is not common.

It appears as if Mycobacterium tuberculosis present somewhere in the body can induce cutaneous reactions as is the case in erythema nodosum and erythema induratum.


Neutrophilic pustulosis and ulcerative colitis.

Vazquez J, Almagro M, del Pozo J, Fonseca E.

Department of Dermatology, Hospital Juan Canalejo, Sir John Moore s/n, La Coruna, Spain.

J Eur Acad Dermatol Venereol 2003 Jan;17(1):77-9 Abstract quote

Neutrophilic pustulosis is currently considered as a part of the spectrum of Sweet's syndrome, and has been associated with inflammatory bowel disease and several other diseases.

We report the case of a 34-year-old male who had been suffering from ulcerative colitis (UC) for several years and who experienced the manifestation of a pustular eruption on both forearms and the abdominal wall during an exacerbation of his bowel disease. Both processes were controlled with steroids per os. The histological picture showed an inflammatory infiltrate composed mainly of neutrophils with scattered neutrophilic epidermal abscesses. Certain distinct clinical and histological characteristics have been described as diagnostic of the pustular eruption of UC.

This picture should be included in the spectrum of the neutrophilic dermatosis, in our case associated with an ulcerative colitis. This is a well documented clinical and histologic case report of a recognized association of inflammatory pustulosis in the course of ulcerative colitis.


Clonality in the setting of Sweet's syndrome and pyoderma gangrenosum is not limited to underlying myeloproliferative disease.

Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, NY, USA.


J Cutan Pathol. 2007 Jul;34(7):526-34. Abstract quote

Background: The neutrophilic dermatoses encompass, among others, Sweet's syndrome (SS) and pyoderma gangrenosum (PG), which are associated with underlying systemic diseases including myeloid dyscrasias.

Methods: On skin biopsies from 16 patients with biopsy-proven SS and/or PG, we performed an X-inactivation assay to detect clonal restriction of neutrophils. There were two patient categories based on known diseases at the time of diagnosis: patients with myeloproliferative disease and patients without myeloproliferative disease.

Results: Among seven patients with acute myelogenous leukemia and two with myelodysplastic syndrome, clonal restriction was found in five; three were homozygous, precluding analysis. Among the seven control patients, infiltrates were clonally restricted in five; one was polyclonal and the other was homozygous for the allele, precluding analysis. Of the five patients with clonally restricted infiltrates, one was subsequently diagnosed with myelodysplasia, one had unexplained neutropenia and an additional patient developed breast cancer. Overall, the incidence of clonality in both groups was the same, averaging 81%.

Conclusion: These findings suggest that clonality in neutrophilic dermatoses, while characteristic of underlying myeloid dyscrasia, is not observed exclusively in the setting of myeloproliferative diseases. The significance of clonal neutrophilic infiltrates unassociated with myeloproliferative disease is unclear, but it may have some implications regarding the pathogenesis of sterile neutrophilic infiltrates. Clonality is well described in the setting of lymphomatoid hypersensitivity, reflecting an overzealous response to antigenic stimuli. One could speculate a similar mechanism operational in cases of apparently reactive SS/PG associated with monoclonality; a localized form of cutaneous neutrophilic dyscrasia is also possible.
Elevated serum granulocyte colony-stimulating factor levels in patients with active phase of sweet syndrome and patients with active behcet disease: implication in neutrophil apoptosis dysfunction.

Kawakami T, Ohashi S, Kawa Y, Takahama H, Ito M, Soma Y, Mizoguchi M.

Department of Dermatology, St Marianna University School of Medicine, Kanagawa, Japan.
Arch Dermatol. 2004 May;140(5):570-4. Abstract quote  

BACKGROUND: Sweet syndrome (SS), an acute inflammatory disease, has clinical and laboratory features similar to those of Behcet disease (BD). Serum levels of granulocyte colony-stimulating factor (G-CSF) are elevated in patients with SS, and exogenous administration of G-CSF has repeatedly been implicated in the causation of SS. Granulocyte colony-stimulating factor is a hematopoietic growth factor that regulates the production and differentiation of neutrophils.

OBJECTIVES: To clarify the role of elevated serum G-CSF levels in patients with active SS and active BD compared with those with inactive SS or BD and healthy controls. To then analyze neutrophil apoptosis in the active state of SS and BD; and to also investigate the influence of autologous serum on neutrophil apoptosis.

METHODS: Serum G-CSF was examined in 5 patients with active SS, 7 with inactive SS, 7 with active BD, 9 with inactive BD, and 5 healthy controls by means of an enzyme immunoassay kit. We measured apoptotic cells in the neutrophil fraction of peripheral blood collections in patients with active diseases and controls by means of flow cytometry.

RESULTS: Serum G-CSF level was significantly higher in patients with active SS than in those with inactive SS. The difference in serum G-CSF levels among patients with active and inactive BD was also significant. Serum G-CSF level was significantly higher in patients with active SS than in those with active BD. Neutrophil apoptosis was significantly higher in patients with active SS than healthy controls. This increased apoptosis rate was also seen in patients with active BD. The increased rate of neutrophil apoptosis was significantly suppressed when the neutrophils were cultured for 18 hours in the presence of autologous active SS serum. Similarly, neutrophil apoptosis was suppressed in the presence of autologous serum in patients with active BD, but not significantly so.

CONCLUSIONS: These findings indicate that increased production of G-CSF in patients with SS and BD may play an important role in the manifestation of these disorders. Given the suppression of neutrophil apoptosis in the active state in the presence of the influence of autologous serum, which includes elevated G-CSF level, we propose that serum G-CSF plays a significant role in the suppression of neutrophil apoptosis. Furthermore, G-CSF-induced suppression of neutrophil apoptosis appears to be deeply involved in the pathogenesis of SS and BD
HYPERSENSITIVITY REACTION Type of hypersensitivity reaction which leads to stimulation of a cascade of cytokines that precipitate neutrophil activation and infiltration
A T-cell mediated immune response has been postulated
HLA J Am Acad Dermatol 1987;37:276-278.
No consistent association
Clonal neutrophilic dermatosis in the setting of CD34 positive AML treated with granulocyte colony stimulating factor

J Cutan Pathol 2001;28:90-96

One case
May reflect therapy induced differentiation of sequestered leukemic cells
Neutrophils displayed dysplastic features


Laboratory Markers  
ESR >90% of cases
Leukocytosis >8000 in 80% of cases
Less common in drug associated cases
Anemia 54%
Usually associated with malignancy
Low platelets Usually associated with malignancy
Alkaline phosphatase elevation 46% of patients
ANCA positive J Am Acad Dermatol 1994;31(4)535-556.


From acute febrile neutrophilic dermatosis to neutrophilic disease: forty years of clinical research.

Department of Dermatology, Hopital Cochin-Tarnier, Paris, France.

J Am Acad Dermatol. 2006 Dec;55(6):1066-71. Epub 2006 Oct 18. Abstract quote

In 1964, Sweet described an acute febrile neutrophilic dermatosis. It is now widely accepted that Sweet's syndrome belongs to a group of associated neutrophilic dermatoses.

Although clinically dissimilar, Sweet's syndrome, pyoderma gangrenosum, subcorneal pustular dermatosis, erythema elevatum diutinum, and a few other conditions can be considered a part of this same pathologic spectrum of inflammatory disorders because of (1) the existence of transitional and overlap forms; (2) the similar histopathologic feature of an infiltrate by normal polymorphonuclear leukocytes; (3) the possible occurrence of extracutaneous neutrophilic infiltrates, defining the neutrophilic disease; and (4) the frequent association with systemic diseases.

According to the localization of the neutrophilic infiltrate, we describe neutrophilic dermatoses en plaques (dermal), superficial (epidermal), and deep (dermal and hypodermal). Almost every organ of the body may be involved by a neutrophilic aseptic inflammation. The main systemic diseases associated with neutrophlic dermatoses are hematologic, gastrointestinal, and rheumatologic diseases.

Although the pathophysiology of these conditions is still poorly understood, treatment with systemic anti-inflammatory agents is usually efficacious.
BONE Sterile osteomyelitis
JOINTS Arthralgia/arthritis (33-62%)
LUNGS Alveolitis

Sweet's syndrome in an infant - report of a rare case.

Prasad PV, Ambujam S, Priya K, Padma K, Rehana T.

Rajah Muthiah Medical College and Hospital, Annamalai University, Annamalainagar, Tamil Nadu State, India.

Int J Dermatol 2002 Dec;41(12):928-30 Abstract quote

A 35-day-old baby girl presented with a history of sudden onset of skin lesions of 4 days' duration. The skin lesions initially appeared on the cheeks, but progressed to involve the trunk and limbss within 4 days. There was a history of upper respiratory tract infection 10 days prior to the onset of the skin lesions. The skin lesions were associated with fever. There was no history or symptoms suggestive of systemic involvement. The child was not on any drugs prior to the onset of the skin lesions.

On examination, the child was febrile with a temperature of 100 degrees F and a pulse rate of 120 beats/min, and weighed 3.8 kg. Cutaneous examination revealed multiple, erythematous, nodular lesions on the face (Fig. 1). A few large bullous lesions were present on the thighs and gluteal region. Multiple tender nodules and a few annular lesions with well-defined discrete papules at the margins and central erythema were also seen on the trunk and limbs. There was no involvement of the mucous membranes. Systemic examination was within normal limits. The investigations revealed a hemoglobin of 7.2 g%, a total count of 30,000 cells/mm3 with a differential count of 79% neutrophils, and an erythrocyte sedimentation rate of 50 mm at 1 h. Urine examination, USG, and pus culture were normal. Human immunodeficiency virus (HIV) screening in the baby and mother was negative.

The histopathologic section revealed a dense inflammatory cell infiltrate involving the epidermis and upper dermis, composed mainly of neutrophils. The epidermis also showed edema and spongiotic vesicles. The inflammatory cell infiltrate was distributed around small blood vessels, as well as the entire upper dermal tissue, together with leukocytoclasis (Fig. 2).

The baby was treated with oral prednisolone, at a dose of 1 mg/kg body weight, and oral potassium iodide (100%), five drops, three times daily. With this regimen, the skin lesions regressed in 4 weeks. Steroids were gradually tapered and oral potassium iodide was continued for four more weeks and then stopped. The lesions resolved with secondary cutis laxa. There was no relapse at the end of a follow-up period of 12 months.


Sweet's syndrome: Recurrent oral ulceration, pyrexia, thrombophlebitis, and cutaneous lesions.

Femiano F, Gombos F, Scully C.

II University of Medicine and Surgery and Eastman Dental Institute.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003 Mar;95(3):324-7 Abstract quote

We report a case of Sweet's syndrome with recurrent oral ulceration, pyrexia, skin lesions, and migratory thrombophlebitis, with no detectable systemic cause, during a 2-year follow-up. Biopsy examination both of oral lesions and the skin eruption showed a characteristic dense, perivascular, neutrophilic infiltrate in the lamina propria. Laboratory investigations confirmed an inflammatory syndrome with an increased erythrocyte sedimentation rate, but no underlying cause was found. Sweet's syndrome is a rare immunologically mediated condition that belongs to the group of neutrophilic dermatoses that must be differentiated particularly from Behcet's disease. It is characterized by red-brown plaques and nodules that are frequently painful and occur primarily on the head, neck, and upper extremities.

Often the patients also have neutrophilia and fever and may have oral ulceration. In approximately 10% of patients with Sweet's syndrome, there is an associated malignancy-most commonly acute myelogenous leukemia-but some cases, as here, are unassociated with detectable malignant or other disease, although the syndrome may precede the onset of definable systemic disease.

The relationship between neutrophilic dermatosis of the dorsal hands and sweet syndrome: report of 9 cases and comparison to atypical pyoderma gangrenosum.

Walling HW, Snipes CJ, Gerami P, Piette WW.

Department of Dermatology, University of Iowa, Iowa City, USA.
Arch Dermatol. 2006 Jan;142(1):57-63. Abstract quote  

BACKGROUND: Neutrophilic dermatoses are a collection of diseases with varying presentation unified by clinical and histologic features. Neutrophilic dermatosis of the dorsal hands is a recently described clinical entity and an evolving disease concept. Its relationship to acute febrile neutrophilic dermatosis (Sweet syndrome), pyoderma gangrenosum, and a primary vasculitis has been debated.

OBSERVATIONS: We present 9 cases (8 women and 1 man) of neutrophilic dermatosis of the dorsal hands, all with consistent histologic features. Two cases had histologic evidence of vasculitis, and 3 had clinical extension of lesions onto the forearms. Most showed fever, leukocytosis, and/or elevated erythrocyte sedimentation rate. Individual cases were associated with leukemia, lung carcinoma, and inflammatory bowel disease. All 9 patients responded to systemic corticosteroid therapy, with additional response to dapsone, methotrexate, and potassium iodide therapies in several cases. Of the 9 patients, 5 showed complete resolution of their skin disease, whereas 4 required ongoing therapy. We assessed the 43 cases previously reported in the literature.

CONCLUSION: The clinical presentation, laboratory data, histologic features, and response to corticosteroid therapy offer strong evidence that neutrophilic dermatosis of the dorsal hands is a localized variant of Sweet syndrome and is also identical to atypical pyoderma gangrenosum when that condition presents on the hands.
Neutrophilic Dermatosis of the Dorsal Hands
(Pustular vasculitis of the hands)

J Am Acad Dermatol 2000;43:870-4

Patients with this condition presented with low-grade fevers and erythematous plaques, pustules, and bullae limited to the dorsal hands and fingers

Biopsy specimens showed a neutrophilic infiltrate and leukocytoclasis, but no necrotizing vasculitis, and were reminiscent of Sweet's neutrophilic dermatoses

Corticosteroids or dapsone led to clearing of the lesions, and small maintenance doses of dapsone prevented their recurrence
Low-dose dapsone is proposed as a possible first-line therapy in this condition, especially in those with recurrent disease

Neutrophilic myositis as an extracutaneous manifestation

J Am Acad Dermatol 2001;44:137-139

Initial presentation in patient who later presented with pyoderma gangrenosum

Sweet's syndrome in acute myelogenous leukemia presenting as periorbital cellulitis with an infiltrate of leukemic cells

Kelli W. Morgan, MD
Jeffrey P. Callen, MD

Louisville, Kentucky

J Am Acad Dermatol 2001;45:590-5 Abstract quote

Sweet's syndrome is characterized by the abrupt onset of fever, neutrophilic leukocytosis, and erythematous, tender pseudovesiculated plaques or nodules that respond readily to corticosteroid therapy. It is usually distinguished by the presence of mature neutrophils on histopathologic examination.

We describe a 38-year-old man with acute myelogenous leukemia who had an erythematous vesicular eruption of the left eye develop that resembled cellulitis.

A biopsy specimen revealed a dermal infiltrate of mature neutrophils and immature myeloblastic precursors. He later had hemorrhagic pseudovesiculated plaques develop bilaterally on his hands. A biopsy specimen again revealed abundant neutrophils with immature forms. A similar eruption developed at the site of a Hickman catheter placement 4 months later. His skin lesions responded rapidly to oral corticosteroids.

This case is unique in that his initial presentation of Sweet's syndrome resembled orbital cellulitis that was characterized by immature myeloid precursors on histopathology.



Dense nodular or diffuse dermal infilrate of neutrophils, nuclear dust, dermal edema, with no evidence of vasculitis

Focal involvement of the subcutaneous fat may occur

Bullous Sweet's syndrome in congenital neutropenia: association with pegfilgrastim.

Draper BK, Robbins JR, Stricklin GP.

Department of Medicine, Division of Dermatology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
J Am Acad Dermatol. 2005 May;52(5):901-5. Abstract quote  

Sweet's syndrome is an acute febrile neutrophilic dermatosis marked by attacks of painful, plaque-forming inflammatory papules accompanied by fever, arthralgias, peripheral leukocytosis, a diffuse dermal neutrophilic infiltrate, and prompt resolution of symptoms and lesions with glucocorticoid therapy.

There are many reports of drug-induced Sweet's syndrome to various medications including all- trans -retinoic acid, carbamazepine, hydralazine, levonorgestrel/ethinyl estradiol, minocycline, trimethoprim/sulfamethoxazole, and granulocyte colony-stimulating factor.

We describe the first known case of Sweet's syndrome induced by pegfilgrastim, a pegylated form of granulocyte colony-stimulating factor with unique pharmacologic properties that may induce Sweet's syndrome in patients with no history of neutrophilic dermatoses associated with granulocyte colony-stimulating factor therapy.

Drug-associated histiocytoid Sweet’s syndrome: a true neutrophilic maturation arrest variant

Angela J. Wu, Timothy Rodgers, Douglas R. Fullen


Journal of Cutaneous Pathology 35 (2) , 220–224 Abstract quote

Histiocytoid Sweet’s syndrome is a recently described entity which has clinical features identical to typical Sweet’s syndrome but is distinguished by a dermal cellular infiltrate composed not of mature neutrophils but of immature granulocytes.

Herein, we report a case of bone marrow granulocytic maturation arrest and a histological histiocytoid Sweet’s-like reaction pattern following trimethoprim-sulfamethoxazole therapy.

Histiocytoid Sweet Syndrome

A Dermal Infiltration of Immature Neutrophilic Granulocytes

Luis Requena, MD; Heinz Kutzner, MD; Gabriele Palmedo, PhD; Marta Pascual, MD; Jesús Fernández-Herrera,
; Javier Fraga, MD; Amaro García-Díez, MD; Evaristo Sánchez Yus, MD

Arch Dermatol. 2005;141:834-842. Abstract quote

Objective  To describe a series of 41 patients with fresh lesions of Sweet syndrome in which the histopathologic study demonstrated an inflammatory infiltrate mostly composed of histiocytoid mononuclear cells.

Design  Histopathologic, immunohistochemical, and cytogenetic studies of the inflammatory infiltrate in a case series of histiocytoid Sweet syndrome.

Setting  University departments of dermatology and a private laboratory of dermatopathology.

Methods  Conventional histopathologic study as well as immunohistochemical investigations were performed using the alkaline phosphatase antialkaline phosphatase technique with a large panel of antibodies. In some cases, fluorescent in situ hybridization studies were performed to investigate the presence of the bcr/abl gene fusion.

Results  Immunohistochemical studies demonstrated that most cells of the infiltrate showed immunoreactivity for CD15, CD43, CD45, CD68, MAC-386, HAM56, and lysozyme, which is consistent with a monocytic-histiocytic immunoprofile. However, intense myeloperoxidase reactivity was detected in most of the cells with histiocytic appearance, which raised the possibility of specific cutaneous involvement by myelogenous leukemia. Nevertheless, cytologic peripheral blood examinations, fluorescent in situ hybridization studies to investigate the bcr/abl gene fusion, and follow-up of the patients, taken all together, ruled out this possibility.

Conclusions  This case series demonstrates that some fresh cutaneous lesions of Sweet syndrome are histopathologically characterized by an infiltrate mostly composed of cells that may be misinterpreted as histiocytes, when in fact they are immature myeloid cells. We named this histopathologic variant histiocytoid Sweet syndrome, which should not be mistaken with leukemia cutis or other inflammatory dermatoses that are histopathologically characterized by histiocytes interstitially arranged between collagen bundles of the dermis.

Immature myeloid precursors associated with myelodysplastic syndrome Am J Dermatopathol 2000;22:429-433

Atypical cells had identical phenotype to the leukemic cells in the peripheral blood and bone marrow

Sweet's Syndrome and Leukemia cutis: A Common Skin Homing Mechanism?

Vignon-Pennamen MD, Aractingi S.

Department of Dermatology and Pathology, Hopital Saint-Louis, Paris, France.

Dermatology 2003;206(2):81-4 Abstract quote
Vascular Inflammation (Vasculitis) in Sweet Syndrome

A Clinicopathologic Study of 28 Biopsy Specimens From 21 Patients

Janine C. Malone, MD; Stephen P. Slone, MD; Lisa A. Wills-Frank, MD; Paul K. Fearneyhough, MD; Sheron C. Lear, HT(ASCP), HTL, QIHC; L. Jane Goldsmith, PhD; Antoinette F. Hood, MD; Jeffrey P. Callen, MD


Arch Dermatol. 2002;138:345-349 Abstract quote

Sweet syndrome is characterized by painful, erythematous plaques of rapid onset accompanied by fever. Absence of vasculitis is a histologic criterion for diagnosis. However, recent reports suggest that vasculitis should not exclude the diagnosis. We hypothesized that vasculitis can occur in Sweet syndrome and that it represents an epiphenomenon rather than a primary immune-mediated process.

Skin biopsy specimens from patients with Sweet syndrome were reviewed to determine the prevalence of vasculitis. The clinicopathologic features of cases with vasculitis were evaluated for statistically significant associations. Specimens with vasculitis underwent immunofluorescence staining.

University department of dermatology, university hospital, and private practice.

Medical records and biopsy specimens of 21 patients meeting diagnostic criteria for Sweet syndrome were reviewed.


The prevalence of vasculitis was 29% (6 of 21 patients). There was a significant association of vasculitis with lesions of longer duration (P = .02). Vascular immunoglobulin and complement could not be demonstrated in cases of Sweet syndrome with vasculitis.

Vasculitis is not a primary, immune-mediated process in Sweet syndrome but occurs secondary to noxious products released from neutrophils. Blood vessels in lesions of longer duration are more likely to develop vasculitis than those of shorter duration because of prolonged exposure to noxious metabolites. Vasculitis does not exclude a diagnosis of Sweet syndrome.



Sweet's Syndrome-Like Blastomycosis.

Wilkerson A, King R, Googe PB, Page RN, Fulk CS.

Am J Dermatopathol 2003 Apr;25(2):152-4 Abstract quote

Cutaneous North American blastomycosis is characterized clinically by verrucous nodules and histologically by pseudoepitheliomatous hyperplasia, intraepidermal neutrophilic microabscesses, and a dermal mixed inflammatory cell infiltrate containing giant cells.

We describe a patient who presented clinically with erythematous nodules and plaques on the lower extremities characterized histologically by a diffuse neutrophilic infiltrate, with lack of epidermal hyperplasia. The lesions were clinically and histologically reminiscent of Sweets syndrome.

On close microscopic inspection scattered histiocytes and multinucleated giant cells were present in the dermis, and fungal stains demonstrated budding yeast forms consistent with Blastomyces sp.

Bowel bypass-related dermatosis  

Chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE) syndrome.

Torrelo A, Patel S, Colmenero I, Gurbindo D, Lendínez F, Hernández A, López-Robledillo JC, Dadban A, Requena L, Paller AS.

Department of Dermatology, Hospital del Niño Jesús, Menéndez Pelayo 65, 28009-Madrid, Spain.

J Am Acad Dermatol. 2010 Mar;62(3):489-95. Abstract quote

Several syndromes manifest as recurrent daily fevers, skin lesions, and multisystem inflammation.

We describe 4 patients with early-onset recurrent fevers, annular violaceous plaques, persistent violaceous eyelid swelling, low weight and height, lipodystrophy, hepatomegaly, and a range of visceral inflammatory manifestations. Laboratory abnormalities included chronic anemia, elevated acute-phase reactants, and raised liver enzymes. Histopathologic examination of lesional skin showed atypical mononuclear infiltrates of myeloid lineage and mature neutrophils. Our patients have a distinctive early-onset, chronic inflammatory condition with atypical or immature myeloid infiltrates in the skin.

We propose the acronym CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature) syndrome for this newly described disorder, which is probably genetic in origin.

Disseminated erythema nodosum  
Erythema elevatum diutinum  
Leukocytoclastic vasculitis  
Pustular vasculitis of the dorsal hands  
Pyoderma gangrenosum  


Recurrence Even after systemic steroid treatment, 25-37% of cases may recur
Treatment Corticosteroids
Systemic corticosteroids
Potassium iodide

Commonly Used Terms

Myelodysplastic Syndrome


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Last Updated March 12, 2010

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