Case Presentation:

Inflammatory polyarthritis and panniculitis are rare sequela of pancreatic disorders. This condition has been termed Polyarthritis, Panniculitis and Pancreatitis (PPP) and occurs in less than 5% of patients with underlying pancreatic disease.  A 64 year old man presented with chronic erythematous, edematous, and tender subcutaneous nodules on all four extremities. He also had bilaterally swollen, red, tender elbows, wrists, knees, ankles and metacarpophalangeal joints. His medical history included alcoholism, hypertension, and pancreatitis.He was admitted for inflammatory arthritis and erythema nodosum. Patient’s labs on day one revealed a white blood cell count of 20.6 K/uL, erythrocyte sedimentation rate was 84 mm/HR, and C-reactive protein of 7.66 mg/dL. His antinuclear antibody was positive, extractable nuclear antigen was negative, rheumatoid factor and CCP antibody were undetectable. Despite the absence of abdominal symptoms, his labs revealed elevated lipase of >15000 U/mL, amylase of 6831 U/mL and CA-19-9 of 197 U/mL. Abdominal imaging showed peripancreatic fat stranding, pseudocyst and ductal dilatation suggestive of chronic pancreatitis. Endoscopic retrograde cholangiopancreatography and biopsy were negative for malignancy. Bilateral hand and wrist x-rays did not show periarticular erosions or osteopenia. Skin and subcutaneous nodule biopsies revealed extensive lobular and septal panniculitis with adipocyte necrosis, lobular aggregates of adipose tissue and superficial MRSA colonies. There were lipocytes with absent nuclei and saponification of fat by calcium salts, which are a feature of pancreatic fat necrosis. Athrocentesis of knee showed MRSA infection. He was treated for pancreatitis, given antibiotics, had a debridement and eventually required bilateral above knee amputations.

Discussion:

A biopsy confirmed the diagnosis of PPP by showing the pathognomonic skin histopathology of ghost cell lobular panniculitis and fat necrosis. Ghost cells are lipocytes with absent nuclei and thickened walls. Panniculitis is predominantly present on lower extremities, but can involve arms, buttocks and abdomen. Polyarticular inflammatory arthritis can be asymmetrical or symmetrical and affect predominantly peripheral joints leading to a presumptive autoimmune inflammatory arthritis. The skin and joint manifestations can precede the abdominal manifestation by up to 6 months and portend to poor morbidity and mortality. Pathogenesis of this syndrome is related to the structural damage caused by lipolysis and proteolysis by pancreatic lipase and amylase. These elevated serum enzymes extravasate and can be found in subcutaneous fat necrosis and the synovial fluid. However, there are reported cases of PPP syndrome with normal serum pancreatic amylase and lipase.

Conclusions:

It is important to recognize the link between PPP as early diagnosis and prompt treatment is essential for satisfactory outcome. Treating the underlying pancreatic disorder can lead to resolution of the skin and joint manifestations, which can prevent inappropriate use of hazardous therapies like steroids and immune-modulators.