RESUMEN
ABSTRACT: Cutaneous perivascular hemophagocytosis (CH) is a histological manifestation that manifests as systemic hemophagocytic syndrome, also known as hemophagocytic lymphohistiocytosis, when accompanied by fever, hepatosplenomegaly, liver dysfunction, and cytopenia, and may rarely manifest independently of hemophagocytic lymphohistiocytosis. CH typically presents as purpuric or brownish macules and patches on the extremities, abdomen, and trunks. Histopathologically, the hallmark of CH includes extravasated erythrocytes and karyorrhectic debris phagocytized by histiocytes, associated with dermal capillary ectasia, perivascular infiltration of neutrophils, nuclear dust, and histiocytes without atypia. In this study, we report 2 cases of CH encountered in routine diagnostic practice and elucidate their significant clinical and histologic features. Our first patient had leukocytoclastic vasculitis with CH in the setting of Yersinia enterocolitis, and the second case represents CH in association with non-Hodgkin lymphoma. This study highlights the importance of considering CH as a potential indicator of underlying systemic pathology, including infectious and hematological disorders, in clinical practice.
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Linfohistiocitosis Hemofagocítica , Humanos , Linfohistiocitosis Hemofagocítica/patología , Masculino , Femenino , Persona de Mediana Edad , Anciano , Vasculitis Leucocitoclástica Cutánea/patología , Linfoma no Hodgkin/patología , Linfoma no Hodgkin/complicacionesRESUMEN
Myeloperoxidase (MPO) is a pro-oxidant enzyme mainly found in the azurophilic granules of neutrophils. It not only displays a key role in the intracellular microbial killing process but also contributes to the extracellular clearance of several pathogens. This study aimed to detect MPO in cutaneous leukocytoclastic vasculitis (LCV) using immunohistochemistry. We retrospectively collected 22 confirmed cases of skin LCV diagnosed in our pathology department over 11 years (2012-2023). Immunohistochemistry was performed using anti-myeloperoxidase antibody (Leica clone 59A5) on the LeicaBond MAX automated system, following manufacturer's instructions. Two pathologists assessed immunohistochemical staining, scoring intensity as weak (+), moderate (++), or strong (+++). Patients' mean age was 56.9 years, with a male-to-female ratio of 1.18. Pathologically, vasculitis involved small blood vessels in all cases. Immunohistochemical analysis showed granular positive MPO staining in 59.1% of cases. Staining intensity was weak in 46.15%, moderate in 46.15%, and strong in 7.69%. Staining was patchy in 84.62% and diffuse in 15.38% of cases. MPO expression, detected in 59.1% of cutaneous LCV tissues, exhibited a patchy and peri-vascular distribution. It holds potential as a diagnostic marker for patients with early or minor histological changes.
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Vasculitis Leucocitoclástica Cutánea , Vasculitis , Humanos , Masculino , Femenino , Persona de Mediana Edad , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Vasculitis Leucocitoclástica Cutánea/patología , Estudios Retrospectivos , Vasculitis/diagnóstico , Vasculitis/patología , Anticuerpos Anticitoplasma de Neutrófilos/análisis , Peroxidasa/metabolismoRESUMEN
Erythema elevatum diutinum is a rare, chronic cutaneous leukocytoclastic vasculitis, with prominent fibrosis at its later stage. In this article, we report a case of erythema elevatum diutinum in a 23-year-old woman with well-controlled Crohn disease. To our knowledge, erythema elevatum diutinum has been reported in only three other cases of Crohn disease, in which eruptions of erythema elevatum diutinum were associated with features of active Crohn. Our patient was in clinical remission at the time of erythema elevatum diutinum onset, making this report significant not only for its uncommon presentation, but more importantly, to aid readers. diagnosis and clinical management of similar cases.
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Enfermedad de Crohn , Vasculitis Leucocitoclástica Cutánea , Humanos , Enfermedad de Crohn/complicaciones , Vasculitis Leucocitoclástica Cutánea/patología , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Femenino , Adulto JovenRESUMEN
Cutaneous lesions of secondary syphilis are highly infectious and can mimic many skin disorders, making the diagnosis more difficult. They typically present as generalized, nonpruritic erythematous-to-copper-colored macules and papules, characteristically involving palms and soles. In 80% of patients the rash develops insidiously. However, rare forms of secondary syphilis present as rapidly progressive papulopustular lesions. These forms of syphilis are usually associated with human immunodeficiency virus infection and immunosuppression. We report a case of secondary syphilis presenting with an acute, rapidly progressive purpuric eruption mimicking leukocytoclastic vasculitis. A 61-year-old man presented with a 6-day history of nonpruritic rash on his chest and lower extremities associated with fatigue, sore throat, and night sweats. Examination revealed purpuric papules, extending from the dorsal feet to the hips; mucosal surfaces were not involved. A diagnosis of cutaneous small-vessel vasculitis was favored with possible triggers of IgA vasculitis. Initial work-up showed acute kidney injury and microscopic hematuria. Renal biopsy showed IgA nephropathy with mesangioproliferative glomerulonephritis. The patient's rash progressed to cover almost his entire body sparing palms and soles. Skin biopsy showed heavy perivascular lymphoplasmacytic infiltrate, capillary endothelial cell swelling, and sparse perivascular neutrophilic nuclear dust. Spirochetal stain highlighted scattered epidermal and dermal organisms.
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Exantema , Sífilis , Vasculitis Leucocitoclástica Cutánea , Masculino , Humanos , Persona de Mediana Edad , Sífilis/complicaciones , Vasculitis Leucocitoclástica Cutánea/patologíaRESUMEN
Erythema elevatum diutinum (EED) is a rare cutaneous neutrophilic vasculitis with many associated diseases reported in the literature. We report a 65-year-old woman with painful and itchy lesions on her elbows, hands, knees, and foot for a year. Histopathologic examination confirmed the diagnosis of erythema elevatum diutinum and treatment with dapsone produced significant clinical improvement within few weeks. Erythema elevatum diutinum is a rare disease that should be considered in patients with violaceous nodular plaques located over the extensor regions of the limbs. Knowledge of this unusual pathology and its association helps to avoid misdiagnosis and late treatment.
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Artritis Reumatoide , Vasculitis Leucocitoclástica Cutánea , Humanos , Femenino , Anciano , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Vasculitis Leucocitoclástica Cutánea/tratamiento farmacológico , Vasculitis Leucocitoclástica Cutánea/patología , Piel/patología , Dapsona/uso terapéutico , Artritis Reumatoide/complicaciones , Artritis Reumatoide/tratamiento farmacológico , Eritema/patologíaAsunto(s)
Neoplasias Cutáneas , Vasculitis Leucocitoclástica Cutánea , Humanos , Quimiocina CCL11 , Quimiocina CCL26 , Eosinófilos , Basófilos , Granuloma , EritemaRESUMEN
Patients with gynecologic vasculitis should be evaluated for systemic disease as prognosis and treatment can vary depending on systemic involvement versus isolated disease. Leukocytoclastic vasculitis is a rare, immune-mediated small-vessel vasculitis. Leukocytoclastic vasculitis of the uterine cervix with systemic involvement has not previously been reported. A 25-year-old female with abnormal cervical cancer screening presented for colposcopy. Biopsies were notable for dysplasia and concurrent leukocytoclastic vasculitis. The patient later recalled a recurrent rash of her lower extremities, suspicious for systemic disease. Patients with gynecologic vasculitis should be evaluated for systemic involvement because prognosis and treatment differ from that of isolated disease. Additionally, leukocytoclastic vasculitis of the uterine cervix may be associated with both hormonal contraception and infections such as human papillomavirus, and any resulting cervical dysplasia should be monitored for progression and treated accordingly.
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Neoplasias del Cuello Uterino , Vasculitis Leucocitoclástica Cutánea , Vasculitis , Adulto , Femenino , Humanos , Detección Precoz del Cáncer , Neoplasias del Cuello Uterino/complicaciones , Neoplasias del Cuello Uterino/diagnóstico , Vasculitis/complicaciones , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Vasculitis Leucocitoclástica Cutánea/complicaciones , Vasculitis Leucocitoclástica Cutánea/patologíaRESUMEN
BACKGROUND Leukocytoclastic vasculitis (LCV) is an atypical form of cutaneous paraneoplastic manifestation. Its association with multiple myeloma (MM) is even rarer and is associated with poor prognosis and short survival, regardless of the therapy instituted. Different treatment approaches are necessary. We present a case in which LCV was the first manifestation of MM, and high-intensity laser therapy (HILT) was used as an option to accelerate healing and control pain. CASE REPORT A 76-year-old woman presented with pain and paresthesia in her lower limbs, associated with palpable purpura. The clinical diagnosis was small-vessel vasculitis. Laboratory tests showed an elevated gamma globulin monoclonal peak on protein electrophoresis. The immunophenotypic study of bone marrow aspirates led to the diagnosis of MM. Due to pain refractory to conventional analgesics, and the progressive evolution of the lesions, despite corticosteroid therapy, we performed photo-biomodulation with a neodymium-doped yttrium aluminum garnet laser (Nd: YAG), wavelength 1064 nanometers, using a 7-mm probe and energy density 6 J/cm². After the first session, the patient was referred for pain management, and after 5 weeks, we observed complete healing in ulcerated lesions and involution of bullous lesions. CONCLUSIONS This case report shows the positive effects of the Nd: YAG laser in modulating healing and reducing pain. HILT is an innovative, non-invasive, and effective treatment and should be considered a promising technique to accelerate healing and controlling pain.
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Terapia por Láser , Mieloma Múltiple , Vasculitis Leucocitoclástica Cutánea , Femenino , Humanos , Anciano , Cicatrización de Heridas , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Dolor , AutoanticuerposRESUMEN
RATIONALE: Kikuchi-Fujimoto disease (KFD) also known as histiocytic necrotizing lymphadenopathy is an exceedingly rare cause of cervical lymphadenopathy, commonly accompanied by systemic symptoms such as fever, fatigue, night sweats, myalgia, skin rash. PATIENT CONCERNS: In this paper, we report the case of a 22-year-old female patient who experienced a flare-up of leukocytoclastic vasculitis that was complicated by the appearance of a cervical lymph node with dysphagia, fever and nausea. DIAGNOSIS: Infectious and autoimmune workup came back negative. INTERVENTIONS: Excisional lymph node biopsy was done and the pathology results were consistent with histiocytic necrotizing lymphadenitis in keeping with Kikuchi-Fujimoto disease. OUTCOMES: Patient improved on intravenous corticosteroids and was discharged on per os prednisone. Six month follow-up shows complete resolution of her symptoms. LESSONS: KFD should be ruled out in patients with autoimmune or inflammatory diseases who develop lymphadenopathies.
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Linfadenitis Necrotizante Histiocítica , Linfadenopatía , Vasculitis Leucocitoclástica Cutánea , Humanos , Femenino , Adulto Joven , Adulto , Linfadenitis Necrotizante Histiocítica/complicaciones , Linfadenitis Necrotizante Histiocítica/diagnóstico , Linfadenitis Necrotizante Histiocítica/patología , Ganglios Linfáticos/patología , Linfadenopatía/patología , Vasculitis Leucocitoclástica Cutánea/complicaciones , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Fiebre/etiologíaRESUMEN
Urticarial vasculitis is a rare autoimmune disorder characterized by persistent edematous papules and plaques on the skin that last longer than 24 hours, often accompanied by systemic symptoms such as joint pain and fever. Unlike common urticaria, this condition involves inflammation of small blood vessels, leading to more severe and long-lasting skin lesions with a tendency to leave a bruiselike appearance. Diagnosis is challenging and may require a skin biopsy. Associated with underlying autoimmune diseases, treatment involves managing symptoms with medications such as antihistamines and corticosteroids, addressing the immune system's dysfunction, and treating any concurrent autoimmune conditions.
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Urticaria , Vasculitis , Humanos , Urticaria/diagnóstico , Urticaria/etiología , Urticaria/inmunología , Vasculitis/diagnóstico , Piel/patología , Piel/inmunología , Diagnóstico Diferencial , Antagonistas de los Receptores Histamínicos/uso terapéutico , Enfermedades Autoinmunes/diagnóstico , Enfermedades Autoinmunes/inmunología , Biopsia , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Vasculitis Leucocitoclástica Cutánea/inmunología , Vasculitis Leucocitoclástica Cutánea/etiologíaRESUMEN
BACKGROUND: Hypercytokinemia, the renin-angiotensin system, hypoxia, immune dysregulation, and vasculopathy with evidence of immune-related damage are implicated in brain morbidity in COVID-19 along with a wide variety of genomic and environmental influences. There is relatively little evidence of direct SARS-CoV-2 brain infection in COVID-19 patients. METHODS: Brain histopathology of 36 consecutive autopsies of patients who were RT-PCR positive for SARS-CoV-2 was studied along with findings from contemporary and pre-pandemic historical control groups. Immunostaining for serum and blood cell proteins and for complement components was employed. Microcirculatory wall complement deposition in the COVID-19 cohort was compared to historical control cases. Comparisons also included other relevant clinicopathological and microcirculatory findings in the COVID-19 cohort and control groups. RESULTS: The COVID-19 cohort and both the contemporary and historical control groups had the same rate of hypertension, diabetes mellitus, and obesity. The COVID-19 cohort had varying amounts of acute neutrophilic vasculitis with leukocytoclasia in the microcirculation of the brain in all cases. Prominent vascular neutrophilic transmural migration was found in several cases and 25 cases had acute perivasculitis. Paravascular microhemorrhages and petechial hemorrhages (small brain parenchymal hemorrhages) had a slight tendency to be more numerous in cohort cases that displayed less acute neutrophilic vasculitis. Tissue burden of acute neutrophilic vasculitis with leukocytoclasia was the same in control cases as a group, while it was significantly higher in COVID-19 cases. Both the tissue burden of acute neutrophilic vasculitis and the activation of complement components, including membrane attack complex, were significantly higher in microcirculatory channels in COVID-19 cohort brains than in historical controls. CONCLUSIONS: Acute neutrophilic vasculitis with leukocytoclasia, acute perivasculitis, and associated paravascular blood extravasation into brain parenchyma constitute the first phase of an immune-related, acute small-vessel inflammatory condition often termed type 3 hypersensitivity vasculitis or leukocytoclastic vasculitis. There is a higher tissue burden of acute neutrophilic vasculitis and an increased level of activated complement components in microcirculatory walls in COVID-19 cases than in pre-pandemic control cases. These findings are consistent with a more extensive small-vessel immune-related vasculitis in COVID-19 cases than in control cases. The pathway(s) and mechanism for these findings are speculative.
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COVID-19 , Vasculitis Leucocitoclástica Cutánea , Vasculitis , Humanos , Vasculitis Leucocitoclástica Cutánea/metabolismo , Vasculitis Leucocitoclástica Cutánea/patología , Microcirculación , SARS-CoV-2 , Vasculitis/patología , Encéfalo/metabolismo , Encéfalo/patología , Autopsia , HemorragiaRESUMEN
Drug hypersensitivity reactions (DHRs) manifested as vasculitis are rare. Antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), sulphonamides, diuretics, immunosupressants and anticonvulsants are the most common culprits for drug-induced leukocytoclastic vasculitis (LCV) but there is scarce information about barbiturates. We present a case of 53-year-old female with severe vasculitis after phenobarbital- and NSAIDs-containing medications use. The preliminary diagnosis of drug-induced vasculitis was made based on anamnestic and clinical data. Further examinations confirmed the diagnosis of LCV and excluded other more common causes of vasculitis. The causative significance of used medications was assessed by long-term observation of the patient after the reaction, including the drug challenge series and Naranjo's Adverse Drug Reaction Probability Scale. It was concluded that phenobarbital is the most probable culprit drug. The patient's data were included in the Armenian Registry of Patients with Severe DHRs. Since then, the patient has avoided only barbiturate-containing drugs and no reactions were noted. Thus, the case indicates that even with limited diagnostic capabilities, the final diagnosis of rare drug-induced LCV and even rarer culprit drug can be established by comparing the available data. Awareness about phenobarbital and proper recording of the case are important in the management and prevention of DHRs manifested as vasculitis.
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Fenobarbital , Vasculitis Leucocitoclástica Cutánea , Humanos , Femenino , Fenobarbital/efectos adversos , Persona de Mediana Edad , Vasculitis Leucocitoclástica Cutánea/inducido químicamente , Anticonvulsivantes/efectos adversos , Antiinflamatorios no Esteroideos/efectos adversos , Hipersensibilidad a las Drogas/etiología , Hipersensibilidad a las Drogas/diagnósticoRESUMEN
OBJECTIVE: Single-organ cutaneous small-vessel vasculitis (SoCSVV) is an inflammatory skin-limited vascular disease affecting the dermal and/or hypodermal vessel wall. Pathogenetically, idiopathic forms are described, as well as the induction from different triggers, such as infections, drugs, and vaccines. Following the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic outbreak, cases of cutaneous vasculitis induced by both COVID-19 and COVID-19 vaccinations have been reported in literature. The aim of this study is to provide the most recent evidence on new etiological factors, clinical features, and management of the SoCSVV. PATIENTS AND METHODS: We included 42 patients (22 women, 20 men) with SoCSVV and no systemic involvement in the study. The mean age of the patients was 57.3 years. Palpable purpura was the most frequent clinical manifestation (38 cases-90.4%). All patients were diagnosed with leukocytoclastic vasculitis by skin biopsy. RESULTS: The etiological factors were as follows: idiopathic in 9 (21%) patients, drug-related in 19 (45%) patients, COVID-19 infection-related in 5 (12%) patients, post-COVID-19 vaccination in 5 (12%) patients, paraneoplastic in 2 (5%) patients, and drug and infection and sepsis in 1 patient each. Among the drug-related cases, 16 (84%) were antibiotic-related, and most of them were beta-lactam antibiotics. Eosinophilia was present in skin biopsy in the cases related to vaccination and drugs, while intense necrosis and vascular damage in the skin were observed in the cases related to COVID-19 infection, unlike the others. A rapid resolution was observed with the cessation of drugs and short-term steroid treatment for the precipitating factors. CONCLUSIONS: SoCSVV is usually associated with drugs, preceding infections, and vaccines. COVID-19 infection and COVID-19 vaccinations have been reported as new etiological factors. SoCSVV indicates that the disease seems to be a mild, self-limiting illness with a good clinical result.
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COVID-19 , Enfermedades Cutáneas Vasculares , Vasculitis Leucocitoclástica Cutánea , Femenino , Humanos , Masculino , Persona de Mediana Edad , COVID-19/complicaciones , Vacunas contra la COVID-19/efectos adversos , Piel/patología , Enfermedades Cutáneas Vasculares/diagnóstico , Enfermedades Cutáneas Vasculares/etiología , Enfermedades Cutáneas Vasculares/patología , Vasculitis Leucocitoclástica Cutánea/diagnóstico , Vasculitis Leucocitoclástica Cutánea/etiología , Vasculitis Leucocitoclástica Cutánea/patologíaRESUMEN
The immune-mediated small vessel vasculitis is known as Schoenlein-Henoch purpura predominantly from pediatrics and in these cases occurs more frequently after infections of the upper airways. In adults, immunoglobulin A (IgA) vasculitis often proceeds more severely und recurrently with the classical tetrad of skin manifestations in the sense of leukocytoclastic vasculitis, joint affection, gastrointestinal involvement and IgA nephritis, in contrast to the mostly mild and self-limiting course in children. The background of this systemic vasculitis with formation of IgA immune complexes is considered to be an altered glycosylation of IgA, as this causes the exposure of binding sites for autoantibodies so that an immune complex reaction can be elicited. This ultimately leads to perivascular deposition of IgA and a further activation of neutrophils. Groundbreaking in the diagnostics is the histological detection of leukocytoclastic vasculitis and in cases of renal manifestations a kidney biopsy with characteristic deposits of immune complexes, which cannot be clearly differentiated from IgA nephropathy. The treatment is aimed at the respective manifestation and is mostly based on consensus recommendations due to the lack of randomized studies. In addition to immunosuppressive medication, in the presence of a chronic kidney disease general nephroprotection is becoming increasingly more important also by inhibition of sodium-glucose transporter 2 (SGLT2). The type and extent of kidney involvement and also rare cardiac manifestations are the main determinants of the prognosis. Continuous medical accompaniment of those affected is necessary due to the possible progression of the disease and the risk of recurrence.
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Vasculitis por IgA , Poliarteritis Nudosa , Vasculitis Leucocitoclástica Cutánea , Vasculitis , Adulto , Humanos , Niño , Vasculitis por IgA/diagnóstico , Complejo Antígeno-Anticuerpo/uso terapéutico , Inmunoglobulina A , Vasculitis/diagnósticoRESUMEN
Neutrophilic dermatosis of the hands (NDDH) is a localized variant of Sweet's syndrome which has been recently introduced. Strutton et al.in 1996 and then in Galaria et al. in 2000 reported cases with violaceous papulonodules on the dorsal surfaces of the hands with histopathological findings of a neutrophilic dermatosis in association with leukocytoclasia, but clinically and histologically without true vasculitis findings. Eventually, they proposed the term NDDH for these lesions (1,2). A 46-year-old man was referred to our outpatient dermatology clinic with a painful ulcerative lesion on the dorsal side of the left hand that had been present for one year. Initially, the lesion had appeared as a small purulent papule, which gradually extended to a large ulcer. The patient underwent frequent referrals to several physicians and had taken a variety of topical and systemic antibiotics, meglumine antimoniate (Glucantime), and amphotericin with the clinical diagnosis of cutaneous bacterial or fungal infections, or leishmaniasis. All of these therapeutic regimes were ineffective in eradicating the lesion. Given the history, he denied any trauma to the site of lesion; he also did not report any similar lesions in his family. The physical examination revealed an extensive tender ulcer of 4×7 cm2 in size, with a shallow violaceous border superimposed on an edematous region on the dorsal side of the left hand. Atrophic scars resulting from old similar lesions were visible on the dorsal aspects of the 3rd and 4th proximal and middle metacarpal joints (Figure 1). The examination of the other parts of the body was unremarkable. Laboratory tests showed an impaired white blood cell count and their differentiation, including leukocytosis (white blood cell count of 16.12/mm3) with neutrophilia (neutrophil percent at 65.9%). Additionally, altered liver function tests were remarkable for high serum levels of AST (SGOT) (105 IU/L) and ALT(SGPT) (355 IU/L), while the total bilirubin and alkaline phosphatase were within normal limits. Hemoglobin levels (13.90 g/dL) and platelet count (272/mm3) were within normal range. The other laboratory tests, including serological tests for fasting blood sugar, hemoglobin A1c, creatinine, BUN, and an immunoassay for ruling out vasculitis lesions (anti-MPO (P-ANCA) and anti-PR3 (C-ANCA)) revealed no remarkable results. An erythrocyte sedimentation rate of 16 mm/h was reported. A biopsy was performed. Histologic features demonstrated a dense, diffuse dermal infiltrate comprised almost entirely of neutrophils. The epidermis was slightly acanthotic and showed small foci of spongiosis, but the inflammatory infiltrate remained largely in the dermis. Sheets of neutrophils were present, admixed with karyorrhectic debris. The infiltrate did not appear to be peri-vascular, and most vessels that could be observed clearly appeared to be undamaged. However, some vessels appeared to show some neutrophils infiltrating vessel walls (Figures 2a, b). Based upon histopathologic examination, the diagnosis of neutrophilic dermatosis of the hands (NDDH) was suggested. The work-up findings for ruling out neoplastic diseases were unremarkable. Clinically, patients with NDDH show various morphologic patterns of the lesions on the dorsal aspect of the hands, including violaceous edematous plaques or ulcers with undermined borders, hemorrhagic bullae, necrotic pyoderma-like lesions with pseudovesiculation, and atypical pyoderma gangrenosum-like lesions (1). This disease is more common in women (70%) than in men (3). NDDH has been reported in association with malignancies (such as leukemia and lymphoma), myelodysplasia, inflammatory bowel diseases, seropositive arthritis, sarcoidosis, HCV infection, and medications (such as lenalidomide, thalidomide, vaccinations, fertilizer, etc.) (1). Among them, neoplastic diseases are the most common association, which has been reported in 27% of the cases. It may thus represent a paraneoplastic phenomenon (3). Histopathological study is mandatory for achieving a definite diagnosis of NDDH. Its pathological findings include subepidermal edema, a dense and diffuse dermal infiltration of neutrophils along with leukocytoclastic debris, and extravasated erythrocytes, which are not associated with true vasculitis (1,3). However, the presence or absence of some vasculitic features as a histopathological finding depends on the time of biopsy with regard to the evolutionary phases of the lesion (3). In our case, the diffuse nature of the infiltrate was somewhat indicative against the diagnosis of leukocytoclastic vasculitis. Additionally, the possibility of infection was excluded empirically (due to the ineffectiveness of previous therapies without doing cultures or PCR), and indirectly through biopsy. Cohen (4) and Cohen and Kurzrok (5) explained the presence of vasculitis in Sweet's syndrome and NDDH as an epiphenomenon in which the damaged vessel is as an "innocent bystander" in the background of an inflammatory dermatosis. Eventually, they concluded that the presence or absence of vasculitis has a secondary importance in the diagnosis of NDDH. The following entities should be considered in the differential diagnoses of NDDH: cutaneous infections, vesiculobullous pyoderma gangrenosum (atypical), bullous erythema multiforme, pustular drug reactions, rheumatoid neutrophilic dermatosis, bowel-associated dermatosis-arthritis syndrome, and erythema elevatum diutinum (1-3). In our case, based on the pathological examination, the differential diagnosis included neutrophilic dermatosis such as Sweet's syndrome or neutrophilic dermatosis of the dorsal hands. It is essential to exclude an infectious etiology that might include a bacterial infection, or less likely a fungal or atypical mycobacterial infection, given the lack of any granulomatous component. However, some atypical mycobacterial infections can demonstrate a brisk neutrophilic infiltrate and relatively sparse granulomatous responses (6). For the same reason (lack of significant histiocytes), we thought that palisaded neutrophilic and granulomatous dermatosis associated with connective tissue disease was less likely. The relationship between this disease entity and a superficial variant of pyoderma gangrenosum remains unclear. The treatment of NDDH includes systemic corticosteroids, dapsone, methotrexate, potassium iodide, colchicine, and minocycline (2). NDDH is often misdiagnosed as an infectious condition, which can result in inappropriate antibiotic therapy, surgical debridement, and even amputation (7). Therefore, early diagnosis and initiation of appropriate treatment should be mainstay of its treatment.