Eosinophilic Cellulitis After Honeybee Sting

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.

[Wells syndrome misdiagnosed as bacterial cellulitis]

Wells syndrome (WS), also called eosinophilic cellulitis is a rare inflammatory skin disease with about 200 cases reports in the literature. It is part of eosinophilic dermatoses and presents a diagnostic challenge. We report a case of WS presenting as bacterial cellulitis. A 59 year-old woman was referred to our department with a 10-day history of a rapidly extending erysipelatoid rash of the left upper limb, non-responding to oral antibiotics. Upon physical examination, erythema with swelling and blisters were found on the left upper limb with urticarial-like lesions on the breast, the belly and on the inner thighs. The patient was admitted with presumed bacterial cellulitis and was treated with intravenous ampicillin. Blood count showed raised eosinophils (2050/ul) along with a biological inflammatory syndrome. Biopsies were performed on both bullous and urticarial-like lesions showing perivascular and interstitial inflammatory infiltrate, made essentially of eosinophils with flame figures. The diagnosis of WS was made and the patient received local and oral corticosteroids (0,5mg/kg/d) with good evolution. The rarity and clinical manifestations of WS makes it sometimes difficult to differentiate between a WS and a bacterial cellulitis. However, biological and histological findings can help the clinician make the differential diagnosis between these two diseases for a better management.

Two cases of wells syndrome with marked swelling in the hands

Wells syndrome or eosinophilic cellulitis is an idiopathic inflammatory dermatitis characterized by a benign but recurrent evolution. It often causes edematous urticarial plaques on the extremities. Herein, we report two rare cases of Wells syndrome with marked swelling in the hands. Both cases exhibited various clinical features. Case 1 was Wells syndrome with collagen disease-like sclerotic edema in the fingers and annular erythema on the trunk. Case 2 was Wells syndrome with diffuse plate-like hardening of the forearm mimicking cellulitis, which required fasciotomy due to suspected compartment syndrome at the emergency room. Wells syndrome should be included in the differential diagnosis of patients presenting with marked diffuse swelling in the hands.

Evaluation of inflammatory skin infiltrate following Aedes aegypti bites in sensitized and non-sensitized mice reveals saliva-dependent and immune-dependent phenotypes

During probing and blood feeding, haematophagous mosquitoes inoculate a mixture of salivary molecules into their vertebrate hosts' skin. In addition to the anti-haemostatic and immunomodulatory activities, mosquito saliva also triggers acute inflammatory reactions, especially in sensitized hosts. Here, we characterize the oedema and the cellular infiltrate following Aedes aegypti mosquito bites in the skin of sensitized and non-sensitized BALB/c mice by flow cytometry. Ae. aegypti bites induced an increased oedema in the ears of both non-sensitized and salivary gland extract- (SGE-)sensitized mice, peaking at 6 hr and 24 hr after exposure, respectively. The quantification of the total cell number in the ears revealed that the cellular recruitment was more robust in SGE-sensitized mice than in non-sensitized mice, and the histological evaluation confirmed these findings. The immunophenotyping performed by flow cytometry revealed that mosquito bites were able to produce complex changes in cell populations present in the ears of non-sensitized and SGE-sensitized mice. When compared with steady-state ears, the leucocyte populations significantly recruited to the skin after mosquito bites in non-sensitized and sensitized mice were eosinophils, neutrophils, monocytes, inflammatory monocytes, mast cells, B-cells and CD4⁺ T-cells, each one with its specific kinetics. The changes in the absolute number of cells suggested two cell recruitment profiles: (i) a saliva-dependent migration; and (ii) a migration dependent on the immune status of the host. These findings suggest that mosquito bites influence the skin microenvironment by inducing differential cell migration, which is dependent on the degree of host sensitization to salivary molecules.

Treatment of eosinophilic cellulitis (Wells syndrome) - a systematic review

Eosinophilic cellulitis (Wells syndrome) is a rare inflammatory skin disease defined by erythematous, tender, sometimes urticarial plaques, possibly with vesicles and bullae, and granulomatous eosinophilic infiltrates in the dermis. Usually the disease has a benign course with spontaneous remission within a few weeks. Nevertheless, recurrences are quite frequent and may occur for several years. The objective of this study was to review the so far reported treatment options for Wells syndrome in a systematic manner. This systematic review is based on a search on Medline, Embase and Cochrane Central Register for English and German articles from 1970 to 2015. Advices on the treatment of Wells syndrome are limited predominately to case reports or to small case series. There are no randomized controlled trials, and control groups are missing. A variety of treatment options for Wells syndrome were reported including topical and systemic corticosteroids, antihistamines, cyclosporine, dapsone, azathioprine, griseofulvin, doxycycline, minocycline, antimalarial medications, oral tacrolimus/topical tacrolimus, sulfasalazine, interferon alpha and gamma, TNF alpha inhibitors, colchicine and PUVA therapy. As well-designed, randomized controlled trials are missing, no guidelines for the treatment of this disease can be given. Due to the small number of patients and the frequent misdiagnosis of this clinical entity, the aim of this systematic overview is to call attention to this rare condition and to help clinicians to diagnose and treat Wells syndrome effectively. Due to the good prognosis and tendency to resolve, systemic treatment should be limited to cases resistant to local therapy or with widespread lesions.