Hypereosinophilic dermatitisD72.1

Rare, idiopathic (polyetiologic), possibly monoorganic, dermatologic "minus variant" of hypereosinophilia syndrome, with an eminently chronic, relapsing course of disease characterized by considerable pruritus.

Trunk and extremities with recess of head, palmae, plantae, glans penis and vulva.

Often rather discrete, initially variable exanthema with disseminated, hardly pinhead- to 0.5cm large, red, usually extremely itchy, spots, papules and also papulovesicles. In the exanthematous eruption phase of hypereosinophilic dermatitis, there is usually a urticarial component in the exanthema. With prolonged persistence, this gives way to a usually discrete, rarely more pronounced lichenification of the lesions.

Theleading symptom of the clinical picture is often excruciating pruritus. Accordingly, fresh and older scratch erosions are frequently detectable. Never, however, is the "scratched" aspect of atopic dermatitis found.

Eosinophilic organ involvement can be excluded.

The transition to a hypereosinophilia syndrome is smooth.

Leading symptom: Persistent or undulating blood eosinophilia >10%. When taking the blood count, it is important to make sure that the patient had not received any external or internal glucocorticoids at the time of blood collection. Multiple blood counts under strict steroid abstinence are recommended!

Vigorous superficial interstitial and perivascular mixed cell dermatitis with marked eosinophilia. Focal epitheliotropy with little or no spongiosis. No evidence of vasculitis.

Note: Biopsy should be performed only after several days of "steroid abstinence-external and internal- ".

Eosinophilic cellulitis, urticaria, atopic dermatitis, pruritus with ACE inhibitors; neurogenic pruritus.

If local therapy is insufficiently successful, systemic treatment with glucocorticoids initially 20-40 mg/day p.o. prednisone equivalent is recommended. Continuous therapy with 5-10 mg/day p.o.

Additively methotrexate can be helpful (10-15mg/week) -s. Casuistry.

Alternative: Good therapeutic results of a multicenter study with a "targeted" therapy with mepolizumab, an anti-IL-5 antibody are available. Mepolizumab could provide new therapeutic options for eosinophilic granulocyte-triggered dermatitis in the future (off-label use).

A 22-year-old woman has been suffering from a generalized, highly pruritic exanthema for 3 years, which has led to marked lichenifications. The skin lesions presented as extensive, even figured, anular plaques on the trunk and extremities. Abundant scratch excoriations were found.

Laboratory: Leukocytosis with eosinophilia (25%) in peripheral blood, elevated serum IgE levels.

Skin biopsy revealed only a moderately dense perivascular and interstitial dermal infiltrate with eosinophils and lymphocytes. Bone marrow examination revealed myeloid hypercellularity with increased numbers of eosinophils but no atypical cells. Cytogenetic studies revealed no chromosomal abnormalities.

Imaging: no evidence of systemic involvement.

Diagnosis: idiopathic, (monoorganic) hypereosinophilic syndrome (hypereosinophilic dermatitis).

Therapy: oral prednisolone and weekly methotrexate. Under this therapy significant improvement of the symptoms.

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