Factors related to the onset and recurrence of flares in hidradenitis suppurativa patients treated with adalimumab

Background Hidradenitis suppurativa (HS) is characterized by periodic worsening of symptoms. However, clinical parameters associated with flare are still to be established. The aim was too investigate factors associated with flare outbreak in HS patients in treatment with adalimumab. Methods Moderate-severe HS patients were included in this retrospective analysis. In total, 115 HS patients treated with adalimumab from 5 Italian centers were reviewed. Gender, ages at onset/baseline, therapeutic delay, family history, body mass index, smoking, comorbidities, phenotypes, body areas involved, Hurley stage, International Hidradenitis Suppurativa Severity Score System (IHS4), Dermatology Life Quality Index (DLQI) and Visual Analogue Scale for pain (pain-VAS) were collected at baseline. Flares were modelled with baseline features using univariate and multivariate Coxregression. The factors significantly correlated with flares in the univariate model were analyzed using a recurrent event survival analysis (Andersen-Gill model) to assess the relation between them and flares recurrence. Results During the observation period 80.9% of patients developed flares, detecting 252 flares, overall. A univariate model identified five risk factors associated with the outbreak of flares: age, therapeutic delay, groin involvement, Hurley III, higher IHS4, whereas, from multivariate model, only IHS4 resulted to be significantly correlated. Additionally, flares were positively associated with higher DLQI and pain-VAS. Finally, the Andersen-Gill model showed four factors correlated with flares recurrence: age, therapeutic delay, Hurley III and higher IHS4. The limitations are: study's retrospective design, absence of a consensus about flare definition. Conclusions An early treatment of HS may prevent both the disease progression and reduce the recurrence of flares.