Exaggerated arthropod-bite lesions in patients with chronic lymphocytic leukemia: a clinical, histopathologic, and immunopathologic study of eight patients

Eosinophilic Dermatosis of Hematologic Malignancy: Emerging Evidence for the Role of Insect Bites-A Retrospective Clinico-Pathological Study of 35 Cases

Background/Objectives: Eosinophilic dermatosis of hematologic malignancy (EDHM) is a rare cutaneous disorder associated with various hematologic malignancies, most commonly chronic lymphocytic leukemia. Detailed clinicopathologic studies of EDHM are lacking and the pathogenesis remains enigmatic. Initially thought to be a hypersensitivity reaction to insect stings, subsequent reports have challenged this understanding. The prognostic implications of EDHM remain unclear. Methods: A retrospective clinicopathologic study was performed on patients diagnosed with EDHM. Hematologic and dermatologic data were reviewed. Histologic specimens were re-evaluated and lesions were classified into acute/subacute, fully developed, and chronic/regressing. Results: The study included 35 patients. In 80% of these patients, EDHM was diagnosed after the hematologic disorder. Approximately 45% of the cohort experienced hematologic disease progression or relapse, while 65% required therapeutic intervention during the course of their hematologic disease. In total, 15/19 CLL patients had non-mutated IgHV, a marker of a more aggressive hematologic disease course. Dermatologic lesion morphology was heterogeneous, with most lesions occurring on exposed areas, and a significant 94% of patients demonstrated lesion seasonality. Histopathologic findings were consistent with features typically associated with insect bites. In addition, examination of lesions at different chronological stages revealed substantial similarities with Wells syndrome. Conclusions: Our findings support the potential role of insect bites in triggering EDHM in the context of adaptive immune dysfunction. EDHM may be associated with a more aggressive disease course or may be a marker of disease progression. The observed co-occurrence of features typical of Wells syndrome in EDHM patients suggests that these conditions are part of a spectrum of disorders that vary in clinical expression.

Eosinophilic dermatosis of hematologic malignancy in patients with chronic lymphocytic leukemia/non-Hodgkin's B lymphoma: a single center prospective clinico-pathological study

Background

The pathogenesis of eosinophilic dermatosis of hematologic malignancy (EDHM) is poorly understood. Previously thought to be a hypersensitivity reaction to insect bites, immune dysregulation and cytokine imbalance are now thought to be responsible. Its prognostic significance is unclear.

Objective

To describe the clinical, pathological and immunological findings in a series of oncohematological patients with EDHM.

Methods

An observational prospective cohort study of oncohematological patients receiving a diagnosis of EDHM between April 2017 and December 2018.

Results

A total of 15 patients with EDHM (10 females and 5 males) were identified among 422 oncohematological patients. Disease presentation varied from firm erythematous papules to more polymorphic presentations. The lesions were most prevalent on the exposed sites, 8/15 patients recalled an insect bite. Lesion seasonality was reported in 13/15 patients. IgE levels were elevated in six patients, circulating IL-4 and IL-5 were within a normal range. Twelve out of 15 patients developed skin manifestations after chemotherapy. The infiltrate could be eosinophil-rich or lymphocytic-rich. Interestingly, the histopathologic findings were in accordance with arthropod bites.

Conclusion

A role for insect bites in EDHM is supported by our findings. EDHM may be related to aggressive hematologic disease.

A Case of Eosinophilic Dermatosis of Hematologic Malignancy Treated With Narrow-Band Ultraviolet B (NBUVB)

Chronic lymphocytic leukemia (CLL) is one of the most common leukemias in adults. It has been associated with a number of dermatologic manifestations, such as leukemia cutis and erythema multiforme. Among the rarer of these findings is eosinophilic dermatosis of hematologic malignancy (EDHM). EDHM was originally characterized as a hypersensitive insect bite-like reaction, despite most patients having no distinct recollection of being bit or having any risk of exposure. Typically, EDHM presents as a pruritic, erythematous eruption, often with papulovesicular lesions, throughout the body. Due to its relapsing course, a number of treatment methods have been proposed, but no standard of care has been established. In this report, we present a recalcitrant case of EDHM in a patient with CLL that responded well to treatment with narrow-band ultraviolet B (NBUVB) light therapy.

Characteristics of Dermatological Patients With Blood Eosinophilia: A Retrospective Analysis of 453 Patients

BACKGROUND

Skin diseases associated with blood or tissue eosinophilia are common. Because these have various clinical manifestations, making the correct diagnosis can be challenging. So far, dermatological patients with concomitant blood eosinophilia have not been characterized.

OBJECTIVE

To investigate patterns of dermatological patients with concomitant blood eosinophilia to obtain information helpful for optimizing disease management.

METHODS

In this retrospective study, demographic and clinical data and diagnostic test results of all patients presenting with dermatoses associated with blood eosinophilia referred to a university center from 2014 to 2018 were extracted from the electronic patient charts and evaluated using descriptive and semantic map analyses.

RESULTS

A total of 453 patients (51.4% females; mean age, 58.4 ± 21.7 years) were included and grouped according to blood absolute eosinophil counts: severe, greater than or equal to 1.5 G/L (n = 87; 19.2%); moderate, 1.0 to 1.49 G/L (n = 73; 16.1%); and mild eosinophilia, 0.5 to 0.99 G/L (n = 293; 64.7%). Most patients presented with chronic (64.6%), generalized skin lesions (75.9%), and pruritus (88.1%). Statistical analyses revealed 3 distinct patterns: (1) mild eosinophilia associated with localized skin disease, age less than 50 years, history of atopy, and diagnosis of eczema or infectious disease; (2) moderate eosinophilia linked to generalized skin lesions, pruritus, age more than 70 years, and autoimmune bullous disease; and (3) severe eosinophilia associated with diagnosis of hypereosinophilic syndromes, drug hypersensitivity, or malignant disease.

CONCLUSIONS

Based on the pattern analysis of patients with dermatoses associated with blood eosinophilia, a diagnostic workup has been developed aiming at setting the correct differential diagnosis in a feasible and effective manner.

Eosinophils in skin diseases

Eosinophil infiltration is a common finding in a broad spectrum of skin diseases, despite the fact that the skin is devoid of eosinophils under physiologic conditions. Although cutaneous eosinophilia is reactive, cytokine-mediated in most cases, diseases with an intrinsic mutation-mediated clonal expansion of eosinophils can also manifest on the skin. As eosinophils are involved in host defense, regulate immune responses, generate pruritus, induce remodeling and fibrosis, and can cause tissue damage, they have the capacity to actively contribute to the pathogenesis of diseases. Recent research provided deeper insights in the mechanisms, e.g., bacterial and viral clearance, blister formation, recruitment of cytotoxic T cells, and generation of pruritus, by which eosinophils might come into action. This review aims at providing an overview on the clinical presentations of eosinophil-associated dermatoses and the current understanding of their pathogenic role in these diseases. Further, we discuss the effects of therapies targeting eosinophils.

Chronic lymphocytic leukemia and the skin: implications for the dermatologist

B-cell chronic lymphocytic leukemia (CLL) is the most prevalent leukemia in the United States, and its diagnosis can have many dermatologic implications. For one, the cutaneous manifestations of CLL include several entities, most notably leukemia cutis, eosinophilic dermatosis of hematologic malignancy, and a heightened risk of skin infections. Additionally, CLL patients are at an increased risk of secondary malignancies, most commonly of the skin. Furthermore, a number of commonly utilized treatments for CLL have cutaneous implications which should be considered in the interdisciplinary management of CLL patients. In this review, we will provide an update on the diverse cutaneous manifestations of CLL and CLL-directed therapies in order to help guide dermatologic management of this increasingly prevalent patient population.

What lies beneath: Cutaneous involvement of mantle cell lymphoma underlying an insect-bite-like reaction

Mantle cell lymphoma (MCL) is an uncommon subtype of mature B-cell non-Hodgkin lymphoma characterized by specific morphologic, immunophenotypic, and genetic characteristics, namely the t(11;14)(q13;q32) chromosomal translocation with resultant cyclin D1 overexpression. MCL has a generally aggressive course and is often widely disseminated at the time of diagnosis. Skin involvement is exceedingly rare and is seldom the first manifestation of MCL. We present a case of MCL in an 84-year-old man with cutaneous involvement as the first manifestation, discovered incidentally after biopsy of a persistent nodule believed to be an insect bite. This case not only serves to raise awareness of the possibility of MCL presenting in the skin but also to point out that MCL can have lesions with both an insect-bite-like reaction and a deeper dermal MCL infiltrate.

Cutaneous manifestations of B-cell chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a malignant lymphoproliferative disease characterized by the accumulation of immature monoclonal B lymphocytes in blood cells, bone marrow, spleen and lymph nodes. This is the most common type of leukemia among the Caucasoid race. When CLL skin lesions occur in about 25% of patients, they are extremely diverse. These lesions can be divided into specific, including infiltration of the skin by leukemic cells and the skin form of Richter's syndrome, secondary skin tumors, nonspecific lesions and associated skin diseases.Leukemic infiltration of the skin in patients with leukemia is called specific skin lesions (SSL). Many authors associate the unfavorable prognosis with the transformation of CLL with specific infiltration of the skin into Richter syndrome, as well as the appearance of SSL before the diagnosis of CLL. The risk of developing various cancer pathologies in patients with CLL is three times higher than in healthy people identical in sex and age. It was found that the risk of skin cancer in these patients is eight times higher than in the healthy population. The most common secondary skin tumors in CLL are basal-cell carcinoma, squamous-cell carcinoma, melanoma, and Merkel tumor.Nonspecific skin changes are extremely diverse and occur in patients with CLL in 30-50% of cases. The most common secondary changes in the skin in CLL are those of infectious nature. There are also increased reactions to insect bites, generalized itching, exfoliative erythroderma, nodular erythema, paraneoplastic pemphigoid, bullous pemphigoid, drug eruption. Concomitant dermatoses in these patients are more severe and often torpid to the previously conducted therapy. There is no doubt that together with the clarification of the etiology and pathogenesis of CLL, particular issues related to the study of clinical and morphological changes in individual organs and systems, in particular the skin, formed at various stages of the development of this disease should be studied in detail. This can not only expand and clarify our understanding of this pathology, but also can help to clarify the essence of the disease.

Chronic Pruritus Responding to Dupilumab-A Case Series

Background: Chronic pruritus is defined as itch lasting for greater than six weeks. Pruritus is a burdensome manifestation of several internal and external disease states with a significant impact on quality of life. Dupilumab has shown promise in treating a number of conditions including atopic dermatitis (AD) and asthma. Its success in reducing pruritus in AD has generated interest regarding its potential application in other pruritic conditions, such as chronic pruritus of unknown origin, uremic pruritus, and pruigo nodularis. Methods: In this retrospective analysis, we present a series of 20 recalcitrant pruritus patients seen at a tertiary center treated with off-label dupilumab at standard AD dosing. Results: Dupilumab was successful at reducing itch in all treated patients, leading to complete resolution in 12/20 patients and an overall mean NRSi reduction of 7.55. Dupilumab was well tolerated with no significant adverse effects. Conclusions: Our case series suggests dupilumab may be a safe and efficacious therapeutic option in several pruritic conditions and demonstrates the need for further studies to better ascertain its place in the pruritus treatment armamentarium.

Lenalidomide in the management of eosinophilic dermatosis of hematological malignancy

Eosinophilic dermatosis of hematological malignancy is a paraneoplastic skin eruption associated with chronic lymphocytic leukemia and other B-cell malignancies. It clinically resembles an insect bite reaction and it can precede the symptoms of the hematological malignancy or be related to a more aggressive course. Different treatments have been proposed, but partial response and recurrence are frequent. Herein, we describe a case of eosinophilic dermatosis associated with mantle cell lymphoma with remission after lenalidomide therapy.

Mantle cell lymphoma presenting with exaggerated skin reaction to insect bites

We present the case of a 62-year-old African-American woman with medical history of hypertension and hyperlipidaemia who presented to dermatology clinic for 'bug bites'. Skin examination showed resolving bullae on the shins and postinflammatory pigment changes. Histopathology showed eosinophilic spongiosis and direct immunofluorescence (DIF) was negative for IgG, IgM, IgA and C3. After returning to clinic with recurrent severe bullous eruptions, the patient presented with anaemia, lymphocytosis, posterior cervical lymphadenopathy and weight loss. An exuberant bite reaction in the setting of lymphoma was suspected. Further workup with haematology revealed elevated IgG level and total protein levels. Flow cytometry showed a B cell lymphoma subtype. Extensive imaging was positive for diffuse lymphadenopathy, with accompanying evidence of Ebstein-Barr virus infection. Our case highlights the importance of considering exuberant arthropod bite reaction in the setting of undiagnosed lymphoma in a patient with bullous eruption and negative DIF.

Eosinophilic dermatosis of hematologic malignancy: Correlation of molecular characteristics of skin lesions and extracutaneous manifestations of hematologic malignancy

BACKGROUND

Skin diseases are frequent in patients with chronic lymphocytic leukemia (CLL) and other hematological neoplasias. Eosinophilic dermatosis (ED) of hematologic malignancy has long been considered a nonspecific cutaneous reaction pattern. Recently neoplastic cells have been shown to be present in ED, thus challenging the classification as a nonspecific dermatosis.

METHODS

We report five patients with ED in association with CLL. We further investigated the presence of neoplastic B-cells in the skin infiltrate by immunohistochemistry and immunoglobulin heavy chain rearrangement and compared these to extracutaneous manifestations of CLL.

RESULTS

The phenotype of the lymphocytic infiltrate was predominately CD3+ (range: 60%-90%). CD20+ and CD79a+ lymphocytes were less frequent, accounting for up to 15% (range: absent - 15%). CD23+ lymphocytes represented up to 20% (range: absent - 20%) of the infiltrate. The analysis of the immunoglobulin heavy chain rearrangement in the skin specimens showed clonal rearrangements in 4/5 patients and in three of these four patients clones were identical to extracutaneous CLL manifestations.

CONCLUSION

Our data show that neoplastic B-cells are very frequently found in ED when systematically evaluated. This findings support the hypothesis that leukemic cells play a pathogenetic role in ED of hematologic malignancy.

Exaggerated arthropod assault: Eosinophilic dermatosis in a patient with small lymphocytic lymphoma

Dermatologic reactions are commonly encountered in clinical practice. Providers must be aware of both the common and uncommon etiologies leading to these eruptions, particularly in patients with underlying malignancies. Establishing the appropriate etiology directs treatment of these conditions, which may be therapy directed at the malignancy itself.

Insect Bite-Like Reaction with Bullous Lesions Mimicking Bullous Pemphigoid in a Patient with Chronic Lymphocytic Leukemia

Patients with chronic lymphocytic leukemia (CLL) rarely exhibit an exaggerated insect bite-like reaction without a history of an arthropod bite. We report a case of an insect bite-like reaction in a 74-year old man with CLL. The patient presented with a 2-year history of recurrent itchy erythematous patches and blisters on the whole body. He had been diagnosed with CLL 2 years ago, and the skin lesions developed 1 month after remission. The result of a skin biopsy was consistent with insect bite. Immunohistochemical staining of the infiltrated cells showed positive reactions for CD3, CD5 and negative for CD20, CD23. Direct and indirect immunofluorescence revealed negative results. The patient was treated with oral prednisolone and dapsone, under the diagnosis of CLL-associated insect bite-like reaction, and showed marked improvement. Dermatologist should be aware of insect bite-like reaction associated with CLL as a distinct disease entity that is similar to insect bite or bullous pemphigoid.

Exaggerated Arthropod Bite: A Case Report and Review of the Mimics

Exaggerated arthropod bite reactions causing hemorrhagic or necrotic bullous lesions can mimic other serious conditions such as cutaneous anthrax, brown recluse spider bite, and tularemia. A 55- year-old, healthy woman presented to the emergency department with a 3.5-centimeter painless, collapsed hemorrhagic bulla at the left costal margin. She was afebrile and had no systemic symptoms. Laboratory evaluation was unremarkable. She was prescribed silver sulfadiazine cream and mupirocin ointment. The area denuded two days later and the lesion completely healed. This case illustrates the broad differential to be considered when evaluating patients with hemorrhagic bullous lesions.

Eosinophilic dermatosis of hematologic malignancy mimicking varicella zoster infection: report in a woman with chronic lymphocytic leukemia and review of the literature

Eosinophilic dermatosis of hematologic malignancy is a rare papulovesicular eruption that presents in patients with hematoproliferative disorders, particularly chronic lymphocytic leukemia. A 59-year-old woman with chronic lymphocytic leukemia who developed eosinophilic dermatosis of hematologic malignancy mimicking varicella zoster infection is described. PubMed database was searched with the key words: chronic, dermatosis, eosinophilic, hematologic, infection, leukemia, lymphocytic, malignancy, varicella, zoster. The papers generated by the search and their references were reviewed. The patient presented, on more than 20 occasions, with a dermatomal vesicular eruption. Her oncologist, based on the clinical presentation, treated each episode as recurrent varicella zoster virus infection. A complete workup of the patient not only demonstrated negative viral studies but also revealed pathologic changes consistent with eosinophilic dermatosis of hematologic malignancy on lesional skin biopsy. The recurrence of the patient's dermatosis was less frequent when her malignancy was under better control. Eosinophilic dermatosis of hematologic malignancy may mimic other reactive dermatoses. The morphology of our patient's recurrent dermatosis resembled varicella zoster virus infection. Disseminated zoster virus infection with dermatomal and non-dermatomal distribution should be added to the clinical differential diagnosis of eosinophilic dermatosis of hematologic malignancy.

Skin: A mirror of internal malignancy

Skin manifestations are a reflection of many of the internal diseases. Sometimes, skin disease may be the only manifestation of the internal disease. Internal malignancies may give rise to a number of cutaneous manifestations through their immunological, metabolic, and metastatic consequences. Curth proposed criteria to establish a causal relationship between a dermatosis and a malignant internal disease. Malignancy can present with a plethora of cutaneous manifestations. Here, we describe in brief about various skin manifestations of internal malignancies.

Arthropod Bites Manifesting as Recurrent Bullae in a Patient with Chronic Lymphocytic Leukemia

Background:

We report a patient with chronic lymphocytic leukemia (CLL) that developed recurrent vesicobullous lesions that histologically demonstrated features of an exaggerated response to an arthropod bite.

Objective:

Patients with CLL can present with many cutaneous manifestations, including specific and nonspecific lesions. Although rare, patients with CLL can develop an exaggerated response to an arthropod bite.

Conclusion:

Emphasis needs to be placed on the clinical recognition of arthropod bites as an unusual cutaneous manifestation of CLL, as they provide the physician with both a diagnostic and a therapeutic challenge. Patients often deny being bitten and, thus, the biopsy results conflict with the patient's history. Additionally, as there is no specific treatment, both the patient and physician are faced with a similar dilemma. Although our patient initially responded well to corticosteroids, his lesions significantly improved while being treated with dapsone.

CLL/SLL with initial presentation as a longstanding cutaneous plaque: a rare case

While chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is the most common leukemia in the western world, it uncommonly initially presents as a cutaneous lesion. When it does, it is often found incidentally in the context of another distinct lesion. We present a case of CLL/SLL that initially presented as a solitary nodular erythematous plaque on the left flank of a healthy 60-year-old man without lymphadenopathy or constitutional symptoms. The lesion had been present for many years, but had recently begun to grow and become pruritic and painful. Excisional biopsy revealed a large nodular aggregate of variably sized CD20(dim), CD5(+), CD23(+), BCL-2(+) atypical lymphocytes in the dermis without epidermotropism. The lymphocytes were negative for BCL-1/cyclinD1, BCL-6, and CD10, and no other background lesion was identified. This constellation of biopsy findings was consistent with CLL/SLL. This case emphasizes the potential for involvement by CLL/SLL in the cutaneous biopsies of otherwise asymptomatic patients.

Clinical categories of exaggerated skin reactions to mosquito bites and their pathophysiology

Mosquito bites are skin irritating reactions, which usually resolve spontaneously without intensive medical care. However, in certain situations, mosquito bites may form a more vicious reaction, sometimes accompanying fever and systemic symptoms. In such cases, the presence of rare hematological disorders, abnormalities in eosinophils and/or association with Epstein-Barr virus (EBV) may underlie. Importantly, hypersensitivity to mosquito bites (HMB), which is characterized by necrotic skin reactions to mosquito bites with various systemic symptoms, is often observed in association with EBV infection and natural killer (NK) cell lymphoproliferative disorder. Exaggerated skin reaction to mosquito bites is also seen in Wells' syndrome. While strong Th2-skewing immune dysregulation is apparent in the patients, they also show robust CD4(+) T cell proliferation in response to mosquito salivary gland extracts, indicating close association between Wells' syndrome and mosquito bites. Similar skin reaction to mosquito bites is also noticed in certain types of B cell neoplasm, although the role of B cells in this peculiar reaction to mosquito bites is yet to be elucidated. In this review, we will discuss the current knowledge of exaggerated reaction toward mosquito bites seen in conjunction with these unique hematological disorders, and examine the scientific studies and observations reported in previous literatures to organize our current understanding of the pathogenesis of this distinct disorder.

Eosinophil-rich syphilis: a report of four cases

The differential diagnosis for eosinophil-rich skin lesions often includes a drug reaction, allergic contact dermatitis and rarely, response to a helminth infection. However, many unrelated entities, such as infections, neoplasms and inflammatory dermatoses, can have a prominent eosinophilic infiltrate. Syphilis is classically associated with plasma cells, but other patterns of inflammation have been reported, including ulcerative, granulomatous and eosinophil-rich. Classic teaching might indicate that the presence of eosinophils argues against a diagnosis of syphilis. We present four cases of secondary syphilis with increased eosinophils, ranging from 8 to >200 eosinophils per 10 high-power fields (×400 magnification). Patient 1 had lesions on the penis and scrotum, with greater than 200 eosinophils per 10 high-power fields. Patient 2 had lesions on the back, with 150 eosinophils per 10 high-power fields. Patient 3 had lesions on the bilateral arms, with 8 eosinophils per 10 high-power fields. Patient 4 had lesions involving the anus, with 17 eosinophils per 10 high-power fields. These cases highlight that the presence of an eosinophil-rich infiltrate on skin biopsy should not exclude syphilis from the differential diagnosis.

Targeting inflammatory pathways in chronic lymphocytic leukemia

Despite recent major advances in leukemia research, the pathobiology of chronic lymphocytic leukemia (CLL) remains poorly understood. Herein we review the role chronic inflammation plays in the initiation and progression of CLL. The robust production of inflammatory cytokines and chemokines accompanied by activation of intra-cellular pro-inflammatory pathways, and the presence of somatic mutations that activate pro-inflammatory signaling pathways, suggest that chronic inflammation plays a pathophysiological role in this disease. Indeed, glucocorticoids and non-steroidal anti-inflammatory possess anti-tumor activity, and glucocorticoids have been broadly used to treat CLL and its complications. Recent clinical trials demonstrated that tyrosine kinase inhibitors, such as ibrutinib and the immune-modulatory agent lenalidomide, induced impressive clinical responses in CLL patients with relapsed or refractory disease. As those pro-inflammatory pathway inhibitors and immune modulating drugs proved to be effective in CLL, other agents with similar activities are currently investigated in clinical trials. New insights into the pathobiology of CLL and the development of novel classes of drugs will undoubtedly provide us with effective tools to treat and perhaps cure CLL.

Insect-bite-like reaction in patients with chronic lymphocytic leukemia: a study from the Israeli Chronic Lymphocytic Leukemia Study Group

An insect-bite-like reaction is known to occur in patients with chronic lymphocytic leukemia (CLL). Most of the literature, however, consists of isolated case reports or small case series. The aim of this retrospective study was to review the national experience with insect-bite-like reaction in a large group of patients with CLL. The study cohort of patients with these skin reactions consisted of 48 patients (25 males, 23 females) of mean age 64.8 yr (range 33-89) at skin eruption. Data on clinical, histologic, immunophenotypic, and cytogenetic characteristics, treatment, and outcome were collected from the medical files. Mean time between diagnosis of CLL and appearance of the skin lesions was 3.1 yr (range -4 to 14 yr). The eruption was not related to disease activity or the course of the hematological disease. The eruption preceded the diagnosis of CLL in 10 patients (by 0-4 yr); and followed the diagnosis in 36; in 11 patients, it occurred during therapy for CLL and in nine after therapy. Mean duration of the skin findings was 21.5 months (range 0.3-132). The eruption usually presented in summer, although it occurred also at other times of the year, and predominantly affected the upper and lower limbs, although it also appeared on unexposed areas. Treatment included local ointments, antihistaminics, oral steroids, antibiotics, phototherapy, and dapsone with varying responses. Insect-bite-like reactions is a relatively common and disturbing skin reaction in CLL patients, it may be related to the immune dysregulation accompanying CLL and further exacerbated by external factors, including actual insect bites, chemoimmunotherapy, and pyogenic infection.

Eosinophilic dermatosis of hematologic malignancy

Cutaneous involvement by an eosinophil-rich process (eosinophilic dermatosis) may be encountered in the setting of various hematologic malignancies, including mantle cell lymphoma, acute monocytic leukemia, acute lymphoblastic leukemia, large cell lymphoma, myelofibrosis and chronic lymphocytic leukemia (CLL). Of the various hematologic malignancies, eosinophilic dermatosis has been most frequently described in association with CLL. Published previously as insect bite-like reaction and eosinophilic dermatosis of myeloproliferative disease, this rare dermatitis presents as a pruritic, papular and occasionally vesicular eruption associated with an eosinophil-rich infiltrate histopathologically. Although clinical and histopathologic features are similar to insect bites, affected patients frequently deny a history of insect bites. We report a case of eosinophilic dermatosis of hematologic malignancy in a patient with known history of CLL.

Roles of the immune system in skin cancer

Over the past several decades, there has been increasing interest in understanding the roles of the immune system in the development and progression of cancer. The importance of the immune system in human skin cancer has been long recognized based primarily upon the increased incidence of skin cancers in organ transplant recipients and mechanisms of ultraviolet (UV) radiation-mediated immunomodulation. In this review, we integrate multiple lines of evidence highlighting the roles of the immune system in skin cancer. First, we discuss the concepts of cancer immunosurveillance and immunoediting as they might relate to human skin cancers. We then describe the clinical and molecular mechanisms of skin cancer development and progression in the contexts of therapeutic immunosuppression in organ transplant recipients, viral oncogenesis, and UV radiation-induced immunomodulation with a primary focus on basal cell carcinoma and squamous cell carcinoma. The clinical evidence supporting expanding roles for immunotherapy is also described. Finally, we discuss recent research examining the functions of particular immune cell subsets in skin cancer and how they might contribute to both antitumour and protumour effects. A better understanding of the biological mechanisms of cancer immunosurveillance holds the promise of enabling better therapies.

Hypersensitivity reaction to a mosquito bite in a patient with chronic myeloid leukemia

A twenty-one-year-old male patient with an exaggerated hypersensitivity reaction to a mosquito bite presented to the department of emergency medicine for further evaluation. He was noted on physical examination to have splenomegaly. The hematological blood tests that were performed were compatible with chronic myeloid leukemia (CML). In this case, the mosquito bite heralded the diagnosis of CML.

Eosinophilic panniculitis and insect bite-like eruption in a patient with chronic lymphocytic leukaemia: a spectrum of the same entity

Background. Eosinophilic dermatosis of hematologic disorders is a reactive process that may cause a variety of clinical manifestations. Methods. We report a patient who had outbreaks of skin lesions since the onset of chronic lymphocytic leukaemia. Results. The cutaneous eruptions began as eosinophilic panniculitis and after changed to insect bite-like lesions. Conclusion. We think that eosinophilic panniculitis and insect bite-like lesions may be part of the spectrum of the same entity in patients with hematologic disorders.

[Eosinophilic dermatosis associated with hematological disorders: A clinical, histopathological and immunohistochemical study of six observations]

BACKGROUND

Eosinophilic dermatosis of hematologic disease (EDH) or insect bite-like reaction is a pruritic dermatitis described mostly in patients with chronic lymphocytic leukaemia (CLL). We describe six patients with the disorder in association with CLL and other blood dyscrasias.

PATIENTS AND METHODS

We reviewed the medical records of patients with EDH seen between 2004 and 2009 in our department and re-examined histological slides.

RESULTS

Mean age at dermatosis onset was 75.6 years and the sex ratio was 1. There were three CLL, two mantle-cell lymphomas and one MALT-type lymphoma. The dermatitis was quite polymorphic, with erythematous papules, wheals and plaques. The initial skin lesions appeared at the same time as or after the diagnosis of haematological neoplasm. Their reappearance heralded relapse of the blood disease in three cases. Histologically, all lesions had a dense dermal infiltrate of small, mostly CD4+ T-cells, with numerous eosinophils. In three patients, there was marked folliculotropism, resembling folliculotropic T-cell lymphoma. In most cases, EDH disappeared after appropriate chemotherapy for the blood disorder.

DISCUSSION

Our cases show that the clinical expression of EDH is quite polymorphic. Its appearance may precede relapse of or may indicate prompt search screening for blood dyscrasia. The most efficient treatment of this dermatosis appears to be specific chemotherapy for the blood dyscrasia. There is reason to believe that a population of T-helper 2 (Th2) lymphocytes, reactive to malignant B-cells, induces tissue eosinophilia, mainly through production of interleukin (IL)-5, among other cytokines. Eosinophils appear to be the main effector cells.

Skin lesions in chronic lymphocytic leukemia

Cutaneous lesions occur in up to 25% of patients with chronic lymphocytic leukemia (CLL). These can be caused by either cutaneous seeding by leukemic cells (leukemia cutis, LC) and other malignant diseases or nonmalignant disorders. Skin infiltration with B-lymphocyte CLL manifests as solitary, grouped, or generalized papules, plaques, nodules, or large tumors. Prognosis in CLL patients with LC is rather good and many authors claim that it does not significantly affect patients' survival. However, prognosis is poor in patients in whom LC shows blastic transformation (Richter's syndrome) and when leukemic infiltrations in the skin appear after the diagnosis of CLL. Secondary cutaneous malignancies are also frequent complications in patients with CLL. A higher risk was seen in skin cancer, for which eightfold higher occurrence has been stated. There are some suggestions that alkylating agents and purine analogs may be associated with an increased incidence of secondary malignancies in CLL. Nonspecific, secondary cutaneous lesions are frequently observed in CLL patients. The most common secondary cutaneous changes seen in CLL are those of infectious or hemorrhagic origin. Other secondary lesions present as vasculitis, purpura, generalized pruritus, exfoliative erythroderma, and paraneoplastic pemphigus. An exaggerated reaction to an insect bite and insect bite-like reactions have been also observed.