High local interleukin 5 production in granuloma faciale (eosinophilicum): role of clonally expanded skin-specific CD4+ cells

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.

Granuloma Faciale and Eosinophilic Angiocentric Fibrosis: Similar Entities in Different Anatomic Sites

BACKGROUND

Eosinophilic angiocentric fibrosis (EAF) and granuloma faciale (GF) share several histopathologic features, including eosinophil-rich inflammation, microangiitis, and progressive fibrosis. Concurrent presentation of EAF and GF suggests a pathogenetic link between them.

OBJECTIVES

To identify histologic findings that tell them apart and construe the pathogenetic mechanisms behind each morphologic variable, 14 immunohistochemical markers were used to study the cells subpopulations in 14 cases of GF and 3 cases of EAF.

MATERIALS AND METHODS

The lesions were classified according to their stage of development. The antibodies studied were: CD4, Foxp3, CD8, granzymes A and B, perforin, granulysin, CD20, CD56, CD68, ICAM-1, CD34, CD105, and 1A4.

RESULTS

The intensity of the sclerotic response and the density of 1A4-immunostained cells were significantly higher in EAF. In both diseases, CD68 cells were the most numerous, followed by CD20, CD8, and CD4 cells. About 30% of cells expressed ICAM-1. Among cells with cytotoxic granules, granulysin-positive cells were the most frequent.

CONCLUSIONS

Differences between GF and EAF were found to be mostly like due to anatomic site (usually skin of the face vs. sinonasal cavity) and stage of the disease development (usually earlier in cutaneous lesions because of their visibility). Innate and adaptive immunity, including B cells, T cells, and cytotoxic granules have a role in their pathogenesis.

Eosinophilia in Dermatologic Disorders

Eosinophil infiltration can be observed in skin disorders, such as allergic/immunologic, autoimmune, infectious, and neoplastic diseases. Clinical presentations are variable and include eczematous, papular, urticarial, bullous, nodular, and fibrotic lesions; pruritus is a common symptom in all. In this review, we present representative eosinophilic skin diseases according to their clinical pattern, together with histologic findings and diagnostic procedures. We also discuss the potential roles of eosinophils in the pathogenesis of dermatologic disorder. Current pathogenesis-based diagnostic and therapeutic approaches are outlined.

Granuloma faciale with extrafacial involvement and response to tacrolimus

Granuloma faciale (GF) is a chronic condition characterized by red-brown plaques with follicular accentuation present usually on the face. We present a case of 35-year-old female with 5 year history of plaques over cheek and extra facial sites consistent with GF and its response to topical tacrolimus. This case supports previous reports of successful treatment of GF with topical tacrolimus.

Successful treatment of granuloma faciale with topical tacrolimus: a case report and immunohistochemical study

We report the case of a 55-year-old Japanese patient with granuloma faciale (GF) successfully treated with topical tacrolimus and describe the immunohistochemical study. Immunohistochemical staining revealed that the patient's granuloma contained CD3⁺, CD4⁺, CD8⁺, CD68⁺ and CD163⁺ cells. Interestingly, these cells contained granulysin⁺ T cells and lacked Foxp3^high+ regulatory T cells. In addition, the macrophages were mainly CD163⁺, which suggested that the alternatively activated macrophage is one of the main components of GF. In summary, the present data shed light on the granuloma-composing cells and possible mechanisms in the treatment of GF with topical tacrolimus.

The interaction of inflammatory cells in granuloma faciale

Granuloma faciale (GF) is a rare chronic inflammatory skin disease characterized by single or multiple reddish-brown cutaneous plaques or nodules. Although this condition is benign, its clinical course is extremely chronic with poor response to therapy. The typical histopathological features of GF include vasculitis with mixed cellular infiltration; however, its etiopathogenesis remains unknown. Here, we describe the case of a 76-year-old man with GF resistant to topical steroids. Biopsy of the lesion revealed i) dense mixed inflammatory cellular infiltrates of lymphocytes, histiocytes, neutrophils, and eosinophils, ii) mild perivascular nuclear dust and swollen endothelium of blood vessels, and iii) a narrow Grenz zone beneath the epidermis. Immunohistochemical staining demonstrated mixed cellular infiltrates intermixed with CD1a⁺ dendritic cells, CD68⁺ histiocytes, and CD4⁺ and CD8⁺ T cells.