Lichenoid dermatitis associated with eosinophilic fasciitis: a case report

Introduction and Objectives Lichenoid dermatitis, also known histologically as lichenoid or interface dermatitis, describes a specific pattern of skin inflammation characterized by damage to basal keratinocytes and dense, band-like lymphocytic infiltrates in the dermo-epidermal junction. Clinically, this dermatitis may present as erythematous or purple papules and plaques, often accompanied by pruritus and post-inflammatory hyperpigmentation. Eosinophilic fasciitis (EF) is a rare autoimmune connective tissue disorder characterized by inflammation of the deep fascia, peripheral eosinophilia, and progressive thickening of the skin and subcutaneous tissue. Although EF is primarily considered a fascial disease, secondary or associated cutaneous manifestations of varying morphology are frequently observed. The treatment of lichenoid dermatitis depends on the severity of the clinical course. Topical glucocorticoids remain the first-line therapy for localized forms, while widespread or refractory cases may require systemic immunosuppressive therapy, including corticosteroids or other immune-modulating drugs. We present a clinical case of a patient with eosinophilic fasciitis who developed histologically confirmed lichenoid dermatitis and discuss the potential association between these conditions, emphasizing their diagnostic and clinical significance. Materials and methods A 59-year-old man was diagnosed with EF in 2024, confirmed by clinical, laboratory, and histological findings. After starting treatment with systemic glucocorticoids (methylprednisolone, later reducing the dose), fascial 9 induration decreased, and inflammatory indicators stabilized (eosinophilia 1.1×10 /L, ENG 15 mm/h, Creactive protein 10 mg/L). ANA and rheumatoid factor were negative. In May 2025, the patient presented with newly developed itchy, erythematous-infiltrated plaques on the trunk. Physical examination revealed reddish-purple shiny plaques covered with fine scales. Due to progressive skin lesions, a punch biopsy was performed. Histopathological examination revealed hyperpigmentation of basal keratinocytes, skin sclerosis, and band-shaped lymphocyte infiltration in the dermo-epidermal junction, consistent with lichenoid dermatitis. Topical treatment with mometasone furoate 0.1% cream once daily for 12 weeks was prescribed, resulting in resolution of scaling and hyperpigmentation, with no emergence of new lesions. Results Treatment with topical glucocorticoids resulted in significant regression of skin lesions. Hyperpigmentation decreased in areas of previous lesions, and no new lesions were observed during the follow-up period. Assessment of both subjective and objective clinical parameters demonstrated a marked improvement in the patient’s quality of life, accompanied by substantial stabilization of skin condition and enhancement of aesthetic appearance. Conclusions This case demonstrates a rare occurrence of lichenoid dermatitis in a patient with eosinophilic fasciitis. Histological confirmation and local glucocorticoid treatment resulted in significant improvement of the skin condition. The importance of skin changes in autoimmune connective tissue diseases and the need for individualized treatment are emphasized.