Sibbald, Cathryn

ABSTRACT Background Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis highly associated with systemic comorbidities. Accurate diagnosis and treatment remain challenging due to its rarity and clinical mimickers. Objectives To evaluate demographic, clinical features and treatment outcomes in patients referred with suspected PG at a tertiary wound care centre. Methods A prospective observational study was conducted of patients referred for suspected PG between April 2021 and June 2023. Demographic, clinical and laboratory data, including biopsies and tissue cultures, were collected. Patients were categorised as having PG vs alternative diagnoses based on diagnostic criteria from Su, Maverakis and the PARACELSUS score. Results Of 60 patients (female, 51.7%; mean [SD] age 52.9 [14.0] years), 44 (73.3%) met at least one published diagnostic criterion for PG. The most common comorbidity was IBD (63.6%), followed by inflammatory arthritis (25.0%) and monoclonal gammopathy of undetermined significance (MGUS) (4.5%). Systemic corticosteroids were used by 40.9% of patients before referral, but steroid‐sparing agents and biologics were the primary treatments after consultation. Biologics and steroid‐sparing agents were associated with significant improvement in disease activity using the PGA score (average score decreased from 2.3 to 1.5, p < 0.005), with 40.9% achieving complete remission. Elevated serum inflammatory markers and faecal calprotectin were observed in PG patients but absent in non‐PG cases. Conclusions These prospective data support previously published rates of association between PG and systemic comorbidities. Steroid‐sparing anti‐neutrophilic and targeted therapies are effective steroid‐sparing strategies in managing PG. Small sample size and referral bias may limit generalisability.

Background There is currently at least 1 biologic (adalimumab) approved in North America for treatment of Hidradenitis Suppurativa in the pediatric population. However, no reviews or clinical trials have specifically analyzed the effectiveness and safety data of biologic use in this population. The objective of this systematic review is to identify and summarize the outcomes of biologic therapy in pediatric patients with HS. Methods MEDLINE and EMBASE databases were used to conduct the search on Sept 18, 2020. Results The 15 included studies consisted of 26 patients, with the mean age of 15 ± 2.3 years. Females accounted for 53.8% ( n = 14/26) of cases. The mean duration of HS prior to biologic initiation was 3.5 ± 2.9 years, with the majority having Hurley Stage II. The 26 patients received 34 biologics in total: 85.3% treated with TNF alpha inhibitors (adalimumab n = 17, infliximab n = 10, etanercept n = 1, unspecified n = 1), 5.9% with IL-12/23 inhibitors (ustekinumab n = 2), 5.9% with IL-1 inhibitors (i.e., anakinra n = 2) and 2.9% received IL-23 inhibitors (i.e., guselkumab n = 1) biologics. Of the 26 patients, 23.1% ( n = 6/26) experienced complete resolution (CR), 73.1% ( n = 19/26) experienced partial resolution (PR), and 3.8% ( n = 1/26) had no resolution outcomes reported. The time to resolution of HS lesions after biologic initiation ranged from 10 days to 11.5 months (mean: 5.1 months). No adverse events were reported in the studies. Conclusion Although anti-TNF alpha were the most common biologics used for HS in pediatric cases, large-scale trials specific to pediatric patients with HS are needed to confirm these findings.