Eosinophilic fasciitis: unraveling the clinical tapestry of a rare case and review of literature.

Eosinophilic fasciitis (EF) remains a diagnostic challenge due to its rarity and resemblance to scleroderma. This case report aims to provide a cohesive exploration of EF's clinical nuances, emphasizing the importance of accurate diagnosis and effective management. A 52-year-old male developed bilateral forearm and calf hardening, along with erythema, pruritus, and pain four months prior to the presentation in our Clinic. The symptoms initially debuted bilaterally in the forearms and progressed to involve the calves, distal arms, and thighs. Clinical examination revealed symmetrical plaques on forearms and calves, featuring erythematous, hyper, and hypopigmented elements extending proximally, a positive "groove sign" and a moderate difficulty in knee joint flexion. Despite these findings, the patient was generally in good condition, without any other notable clinical signs. Initial laboratory findings showed slightly increased percentual eosinophil levels, elevated C-reactive protein (CRP), normal erythrocyte sedimentation rate (ESR), and negative antinuclear and scleroderma specific antibodies. Magnetic resonance imaging (MRI) demonstrated enhanced fascial signal and thickening while the fascia-muscle biopsy revealed marked edema and inflammatory lymphoplasmacytic infiltrate, consistent with the diagnosis of EF. The patient showed a favorable response to systemic corticosteroids. EF predominantly affects males aged 30 to 60 and is characterized by a sudden onset and unclear etiological factors. Differential diagnosis requires careful exclusion of scleroderma and other mimicking conditions. Diagnostic modalities such as skin-muscle biopsy and MRI reveal characteristic findings like inflammatory infiltrate and fascial thickening. Accurate diagnosis and differentiation from scleroderma are crucial, with early intervention involving glucocorticoids and immunosuppressive agents improving long-term outcomes.