The role of eosinophils in the differential diagnosis of inflammatory skin diseases

Eosinophils are known to be present in inflammatory skin diseases, but their diagnostic utility is not well established. Upon review of the published status of lesional eosinophils, several categories were identified. 1) Lesional eosinophils highly characteristic such that, in their absence, the pathologist may question the diagnosis. These include arthropod bite reactions and scabies, urticarial dermatitis, and other eosinophilic dermatoses. 2) Lesional eosinophils rare or absent, such that, in their presence, the pathologist may question the diagnosis. These include pityriasis lichenoides, graft versus host disease, and connective tissue disorders. 3) Lesional eosinophils variable and, while in some cases expected, are not required for diagnosis. These include drug reactions, atopic dermatitis and allergic contact dermatitis. 4) Lesional eosinophils variable and not expected but may be seen to a limited extent. These include lichen planus and psoriasis.

[Eosinophilic annular erythema in a 20-month-old girl]

Wir berichten über ein 20 Monate altes Mädchen mit teils anulären, urtikariellen Hautveränderungen am gesamten Integument, die bis zu 1 Woche persistierten und dann an neuen Stellen auftraten. Die histologische Aufarbeitung zeigte ein urtikarielles Entzündungsmuster mit interstitiellem Ödem und einem Infiltrat mit Lymphozyten, Neutrophilen und vielen eosinophilen Granulozyten ohne Flammenfiguren. Das Labor war unauffällig. In Zusammenschau stellten wir die Diagnose eines eosinophilen anulären Erythems (EAE) im Kindesalter, das zu den eosinophilen Dermatosen zählt.

Flame figures associated with eosinophilic dermatosis of hematologic malignancy: is it possible to distinguish the condition from eosinophilic cellulitis in patients with hematoproliferative disease?

Eosinophilic dermatosis of hematologic malignancy is a multifaceted dermatosis with a wide morphological spectrum, presenting as pruritic, erythematous, papular and occasionally vesicular, urticarial, nodular eruptions. Histopathologically eosinophil infiltration in the super and deep dermis was found. We reported a case of eosinophilic dermatosis of hematologic malignancy presented as urticarial and vesicular lesions in a patient with chronic lymphocytic leukemia. A skin biopsy revealed a prominent subepidermal blister and a diffuse infiltrate of eosinophils with flame figures in the dermis and subcutaneous tissue. Although flame figures associated with eosinophilic dermatosis of hematologic malignancy is rarely reported, we believe that it would not seem unusual to find them in this skin disease. Eosinophilic cellulitis, which share clinical and histological features with eosinophilic dermatosis of hematologic malignancy, has also been described as showing an association with hematoproliferative diseases. In order to clearly describe eosinophilic dermatosis in patients with hematologic malignancies, the terminology eosinophilic dermatosis of hematologic malignancy, instead of eosinophilic cellulitis, would be a more suitable term in patients with eosinophilic dermatosis.