Clinico-histopathological Features of Pyoderma Gangrenosum: A Case Series

Pyoderma Gangrenosum (PG) is a rare, ulcerative, non infectious neutrophilic inflammatory dermatosis and often associated with underlying systemic disorder. The incidence of PG is estimated to be 0.63 per 1,00,000 with the median age at presentation of 59 years. Among its clinical variants, classical PG is the most common. The diagnosis of PG can be difficult. This case series was an attempt to review the new trends for the diagnosis of PG and also to compare them with previous diagnostic criteria. Previously histopathological criteria were included as minor criteria in Su WP et al., classification. More recently proposed diagnostic criteria by Maverkis E et al., include histopathology of skin biopsy from edge of ulcer showing neutrophilic infiltration as a major criteria. Aim of the study is to correlate and stamp the clinically suspected cases of PG with help of histopathology. This retrospective observational case series study was conducted in a tertiary care hospital from May 2018 to April 2020 consisting of 19 cases (15 years to 68 years of age range; 13 males and 6 females). Detailed history, clinical examination and blood investigations were done in all suspected cases of PG followed by histopathological examination of skin biopsy. In 17 cases, lesions were located in lower limb, one case each in buttocks and lower abdomen. The classical, ulcerative form found in 12 cases (63.15%), vegetative form in 3 cases (15.78%), plaque and bullae form were in 2 cases each (10.52%). Pathergy test was positive in 11 cases (57.89%). Histopathological examination showed neutrophilic infiltration in all 19 cases (100%), vasculitis in 11 patients (57.89%), lymphoplasmacytic infiltrate in 6 patients (31.57%), pseudoepitheliomatous hyperplasia in 5 patients (26.31%), mixed inflammatory infiltrate in 4 patients (21%), Epidermal ulceration in 4 patients (21%) and mitosis is seen in 3 patients (15.78%). Histopathology is considered as a main tool which helps clinicians to stamp suspected cases of PG.