Acute pustulosis of the legs in diverticulitis with sigmoid stenosis: an overlap between bowel-associated dermatosis–arthritis syndrome and pustular pyoderma gangrenosum

Background Bowel-associated dermatosis–arthritis syndrome denotes the occurrence of diarrhoea with arthritis and skin lesions related to bowel disease with or without bowel bypass. In this condition, the histological finding of cutaneous aseptic neutrophilic cell infiltrate is non-specific and common to a wide spectrum of neutrophilic dermatoses, including pyoderma gangrenosum.

Observation We describe a 78-year-old woman with fever, abdominal discomfort and arthralgias, who developed grouped pustular lesions on her shins with histologically spongiform pustule formation. Aetiological assessment disclosed diverticular disease with sigmoid stenosis.

Conclusion Although clinical and histological features in our case fit the diagnosis of bowel-associated dermatosis–arthritis syndrome, they may also correspond to a pustular variant of pyoderma gangrenosum. Our observation raises the question of the nosological classification of bowel-associated dermatosis–arthritis syndrome within the spectrum of neutrophilic diseases.