Cll + Pyoderma Gangrenosum

Diagnosis of a neutrophilic dermatosis, such as pyoderma gangrenosum (PG), often is challenging at onset because it can be impossible to distinguish clinically and histopathologically from an acute infection in an immunosuppressed patient, necessitating a detailed patient history as well as correlation pathology with microbial tissue cultures. The dermatologist's ability to distinguish a neutrophilic dermatosis from active infection is of paramount importance, as the decision to treat with surgical debridement, in addition to an antibiotic regimen, can have grave consequences in the misdiagnosed patient...

A 48-year-old patient presented with a nonhealing leg ulcer and a raised white blood cell count. He was diagnosed with pyoderma gangrenosum (PG) and small lymphocytic leukaemia/chronic lymphocytic leukaemia (SLL/CLL). Eight months later, after undergoing treatment with chlorambucil for the SLL/CLL, and prednisone, ciclosporin and intravenous immunoglobulin for the PG, the patient developed livedo reticularis and palpable purpura, and was diagnosed with systemic polyarteritis nodosa (PAN). The case highlights the difficulty in establishing a diagnosis of PAN by biopsy of cutaneous ulcers alone, and that a diagnosis of PG should raise suspicion of another aetiology...