Whipple's Disease: Panniculitis Among Other Dermatoses. A Case Report and Literature Review.

Whipple's disease (WD) is a rare infectious disease caused by Tropheryma whipplei , which primarily affects the gastrointestinal tract but may also involve the joints, central nervous system, and skin. Although cutaneous manifestations are often overlooked, they can provide valuable diagnostic clues. We report the case of a 54-year-old male with long-standing seronegative migratory polyarthritis refractory to conventional treatment, who subsequently developed multiple subcutaneous inflammatory nodules and systemic symptoms. Histopathological examination of these lesions revealed a non-vasculitic, septal-predominant panniculitis with foamy macrophages containing periodic acid-Schiff (PAS)-positive diastase-resistant intracytoplasmic inclusions, raising a strong suspicion of Whipple's disease. Subsequent duodenal biopsies confirmed the diagnosis by electron microscopy and polymerase chain reaction (PCR) for T. whipplei . Panniculitis in WD represents a highly specific but rarely reported finding, characterized by thickened subcutaneous septa with partial lobular involvement, foamy macrophage infiltration, and absence of vasculitis. A literature review identified 15 cases of histologically confirmed WD-associated panniculitis, suggesting that this manifestation may be under-recognized in clinical practice. This study underscores the importance of cutaneous pathology in WD and expands current knowledge on its dermatological manifestations by providing clinicopathologic, ultrastructural, and literature-based data.