DEMODEX-INDUCED CUTANEOUS PSEUDOLYMPHOMA

Abstract

Cutaneous Pseudolymphoma, also referred to as Lymphoid Infiltrate of the Skin, is defined as a benign, inflammatory, reversible, reactive, and polyclonal proliferation of lymphocytes that spontaneously regresses or resolves following the elimination of the triggering factor. Cutaneous pseudolymphomas represent a heterogeneous group of T-cell or B-cell lymphoproliferative disorders, which may be localized or disseminated, and which clinically and histopathologically mimic cutaneous lymphomas. The literature describes various potential etiological factors, including endogenous (genetic, immunological) and exogenous factors (insect bites, medications, vaccinations, ultrasound exposure, trauma, tattoos, acupuncture, infections, etc.).

We present the case of a 64-year-old patient with pruritic nodular lesions on the face, neck, and back, as well as chronic blepharitis, persisting for over a year despite various therapeutic approaches (topical corticosteroids, antifungals, and antibiotics). Based on clinical examination and detailed anamnesis, our differential diagnoses included follicular mucinosis, cutaneous lymphoma, sarcoidosis, and facial eosinophilic granuloma. A skin biopsy was performed (from a nodular lesion on the frontal region), revealing an increased presence of Demodex mites and histopathologically numerous mites and scattered eosinophils. Immunohistochemical analysis demonstrated an immunophenotype of CD4>CD8, CD20(+), CD60(+), Ki67, and CD137, consistent with a benign reactive process. The diagnosis of pseudolymphoma was established based on clinical presentation and histopathological evaluation. Three months of local and systemic antiparasitic therapy led to complete regression of symptoms.