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Eosinophilic Dermatosis In Hematological Malignancy (EDHM): Case Study Reports

Eosinophilic Dermatosis In Malignancy (EDHM): Case Study Reports


Patients with hematological malignancies may develop various skin eruptions, and one such condition is eosinophilic dermatosis of hematological malignancy (EDHM), also known as an ‘insect bite-like’ reaction. While cutaneous reactions are not uncommon in hematological malignancies, EDHM is a relatively rare condition that has been reported in a wide range of hematological cancers, with chronic lymphocytic leukemia (CLL) being the most commonly associated one. Despite its association with these malignancies, the exact pathogenetic mechanism of EDHM remains unclear and warrants further investigation.

The objective of this study was to gain a deeper understanding of EDHM by conducting a comprehensive review of the available literature on this rare condition. Additionally, the authors aimed to discuss the nosological status of EDHM in relation to several other differential diagnoses commonly encountered in clinical practice.

The study involved a retrospective analysis of nine patients diagnosed with EDHM. The researchers carefully examined both the clinical and histological features of these patients to better characterize the condition. Notably, the clinical appearance of the skin eruptions varied among the patients, with some presenting with macules, papules, nodules, vesicles, or bullae. Moreover, the eruptions tended to affect anatomically widespread areas, often on unexposed parts of the body. One patient even exhibited widespread erythematous macules.

An essential finding in this study was that eight out of the nine cases had an underlying hematological malignancy. In one intriguing case, the cutaneous eruption itself led to the diagnosis of splenic marginal zone lymphoma, illustrating the clinical significance of recognizing such skin manifestations in patients with hematological malignancies.

The histological analysis of the skin biopsy specimens was a critical component of the study. In all cases, eosinophils were consistently identified, indicating their central role in the pathogenesis of EDHM. The biopsies also revealed other common features, including bullae, lymphocytic infiltrates, and apoptotic keratinocytes. Interestingly, CD20(+) B-cells, which are associated with B-cell malignancies, were only observed in one case. This observation could be significant in understanding the potential role of B-cells in EDHM pathogenesis.

Overall, the study successfully presented a series of nine patients with EDHM, each associated with different hematological malignancies and manifesting diverse clinical presentations. Despite these variations, the histological features were consistent, suggesting a common underlying mechanism. The authors hypothesize that EDHM is most likely driven by a dysregulated immune system, leading to a T-cell and eosinophil-mediated hypersensitivity reaction. However, further research is required to fully elucidate the complex pathophysiology of this uncommon condition.

Managing EDHM is challenging due to its varied clinical presentation and limited treatment options. Previous reports have attempted various therapeutic modalities with mixed results, including topical and oral corticosteroids, antibiotics, antihistamines, dapsone, phototherapy, radiation, interferon alpha, intravenous immunoglobulins, and reinitiation of chemotherapy. Recent attempts with lenalidomide and dupilumab have shown some short-term efficacy in treating EDHM and delaying the use of chemotherapy. However, treatment remains primarily directed at addressing the underlying hematological malignancy.

In conclusion, this study sheds light on the rare condition of eosinophilic dermatosis of hematological malignancy (EDHM) and its association with various hematological cancers. The findings underscore the importance of recognizing cutaneous manifestations in patients with hematological malignancies, as these skin eruptions can provide valuable diagnostic clues. Further research into the pathogenesis and management of EDHM is warranted to improve the care and outcomes of patients with this intriguing condition.


Patients with hematological malignancies, such as lymphoma or leukemia, often experience cutaneous eruptions, which are skin reactions that can vary in appearance and severity. One specific cutaneous reaction observed in these patients is eosinophilic dermatosis of hematological malignancy (EDHM). Initially considered a rare phenomenon, recent studies have shed light on its prevalence, suggesting that around 7% of chronic lymphocytic leukemia (CLL) patients may develop EDHM.

The clinical presentation of EDHM closely resembles insect bites, with patients exhibiting skin lesions that can appear as macules, papules, nodules, vesicles, or bullae. These eruptions are often intense in their pruritic nature, causing significant itching and discomfort. Interestingly, patients deny any history of being bitten, indicating that these lesions are not caused by actual insect bites.

While CLL is the most commonly associated hematological malignancy with EDHM, there have been reports of this condition occurring in other B cell malignancies as well. Additionally, there is evidence suggesting that EDHM can manifest in T-cell lymphomas, including mycosis fungoides and aggressive peripheral T-cell lymphoma. This highlights the potential diversity in the types of hematological cancers that can be linked to EDHM.

The study presents a series of nine cases of EDHM, including one previously published case, where patients exhibited varying clinical and histopathological features in association with their underlying hematological malignancies. It adds valuable information to the existing literature on this rare condition and contributes to a deeper understanding of its clinical manifestations.

In-depth exploration of EDHM is essential to recognize and manage this cutaneous reaction effectively. Early detection and diagnosis are crucial, as the skin lesions may precede or prompt the diagnosis of hematological malignancy in some cases. Understanding the pathogenesis of EDHM is vital in developing targeted treatment approaches to alleviate symptoms and improve patients’ quality of life.

The study postulates that the underlying mechanism of EDHM is likely related to a dysregulated immune system, which leads to a hypersensitivity reaction involving T-cells and eosinophils. This dysregulation may be driven by the altered immunological state in the skin of patients with hematological diseases.

Although therapeutic options for EDHM are limited, it is essential to manage the condition effectively, especially considering that the treatment is most effectively directed at the underlying hematological malignancy. Further research is needed to investigate potential treatment modalities and their efficacy in managing EDHM.

In summary, the study expands our knowledge of EDHM and its association with various hematological malignancies. Understanding the clinical presentation, histopathology, and potential mechanisms of this rare cutaneous reaction can aid in early diagnosis, improve patient care, and contribute to the development of targeted treatment approaches for this intriguing dermatological condition.


In this retrospective study, the authors gathered clinical information from nine patients who presented with cutaneous eruptions and were diagnosed with eosinophilic dermatosis of hematological malignancy. The clinical data were collected from various sources, such as clinical notes, online records, and histopathological request forms. The researchers also reviewed histopathology sections, including immuno-histochemical stains, to record and analyze the observed features of the skin lesions. This approach aimed to gain a comprehensive understanding of the characteristics and histological aspects of eosinophilic dermatosis in the context of hematological malignancies.


The study involved nine patients with eosinophilic dermatosis of hematological malignancy (EDHM). The patients, aged between 45 and 79, presented with widespread and diverse cutaneous lesions affecting various body parts, often on unexposed areas. The lesions included macules, papules, nodules, vesicles, or bullae, and were intensely pruritic. None of the patients reported a history of insect bites.

Eight patients had a known underlying hematological malignancy, such as Hodgkin’s disease, marginal zone lymphoma, chronic lymphocytic leukemia (CLL), follicular lymphoma, or mantle cell lymphoma. In a single case, EDHM resulted in the identification of splenic marginal zone lymphoma. Dermatologists considered EDHM as the primary diagnosis in five cases, while other differential diagnoses included drug reactions, vasculitis, prurigo, and cutaneous involvement by the lymphoma.

Skin biopsies were performed in all cases, revealing papillary dermal edema and a mixed eosinophil-rich lymphocytic infiltrate. Eosinophils were present in all biopsies, with varying numbers. Some cases showed red cell extravasation, but vasculitis was not observed. Eosinophilic folliculitis was not present, but perifollicular inflammation was seen in one biopsy. Notably, one case without a known hematological malignancy showed dermal eosinophils without bulla formation or papillary dermal edema, and subsequent investigations revealed splenic marginal zone lymphoma, which resolved after splenectomy.

Lymphocytic infiltrates were significant in seven specimens and consisted mainly of T-cells without atypia. In one case of CLL, there were CD20(+) B-cells indicative of likely involvement by CLL, which responded to therapy.

One case initially suggested eosinophilic Sweet’s syndrome due to the presence of dermal eosinophils and neutrophils without significant epidermal changes, but a subsequent biopsy revealed characteristic changes, including a bulla. In two other cases, a minority of the infiltrate included neutrophils.

The study provided valuable insights into the clinical and histopathological features of EDHM, highlighting its association with various hematological malignancies and the importance of skin biopsies for diagnosis and differential diagnosis considerations.


The study presents a series of nine cases of eosinophilic dermatosis of hematological malignancy (EDHM), a rare and intensely pruritic cutaneous reaction occurring in patients with hematological malignancies. EDHM was previously considered rare, but recent studies indicate it may be more prevalent than thought. The eruption can occur either at the time of diagnosis or months to years later, and in some cases, the skin reaction preceded the diagnosis of malignancy.

The clinical presentation of EDHM can resemble insect bites or papular urticaria, leading to differential diagnoses like scabies, drug reactions, or leukemia cutis. Skin biopsies reveal a lymphocytic infiltrate dominated by reactive memory T cells, but some cases also show the presence of small populations of leukemic B cells. The pathogenesis of EDHM is not fully understood, but it is believed to be a T-cell and eosinophil-driven hypersensitivity reaction to unknown antigens influenced by the altered immunological state in patients with hematological malignancies.

EDHM poses a challenge to manage, and various treatments have been attempted with limited success. Treatment options include corticosteroids, antibiotics, antihistamines, dapsone, phototherapy, and intravenous immunoglobulins. Some patients have responded to lenalidomide and dupilumab. However, the most effective approach is directed at treating the underlying hematological malignancy.

In conclusion, EDHM is an uncommon but significant cutaneous reaction associated with hematological malignancies. The immune dysregulation in these patients likely contributes to the hypersensitivity reaction. Current therapeutic options are limited, highlighting the importance of addressing the underlying malignancy for effective management.

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