LAUSR

We are reading with interest or with some perplexity many articles concerning safety of biologicals administration in psoriasis (PsO) patients (1,2). While a lot has been said concerning biologicals and PsO, less interest has been given to biologics and hidradenitis suppurativa (HS) in Coronavirus Disease 2019 (COVID-19) pandemic. We would like to express our considerations and comments in this peculiar field. Biological agents, mainly anti-tumor necrosis factor (TNF)alpha Adalimumab (ADA), currently used for the treatment of HS, represent the cornerstone of treatment for many patients. All biologics are able to block a defined pathogenetic key, modulate the immune system and are considered immunosuppressive drugs. Data from the literature, concerning risk of infections in HS patients upon ADA treatment, in PIONEER I and II trials, are reported by Blaszczak et al. (3) but, in general, there are not many data in the literature concerning the risk of developing infections of the respiratory tract caused by RNA viruses in patients undergoing biological treatment. Bello et al. have reported no serious complications or hospitalizations among a cohort of 159 patients treated with biological agents during the pandemic influenza (a negative sense single-stranded RNA virus) season 2009–2010 (4). In these days, the most frequently asked question from our HS patients in treatment with ADA is regarding the severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) spread infection and the fear to get the disease. Therefore, they constantly ask: “Should I stop the immune-suppressive therapy to limit the risk to become infected and develop the disease?”. The correct answer to this question involves the use of precautionary strategies: to avoid traveling to epidemic areas, to comply with general and specific hygienic rules (e.g. frequent hand washing with soap and water for at least 20 s, cover your cough or sneeze with a tissue), to not use antibiotics (without medical prescription) and, among those with COVID-19, to discontinue treatment with immunosuppressant drugs until the disease is cured. In the absence of both, specific symptoms (fever, cough and shortness of breath) and close contact with a patient with COVID-19 or with the infected person’s secretions, currently, in our opinion, there is no indication -to the best of our knowledge as beginning of May 2020to discontinue the biologic treatment. This specific advice for HS patients is based (taking into account known risks of influenza virus) on the rationale that COVID-19 severity, as happened for other coronavirus outbreaks, is in part linked to a “cytokine storm” that has to be controlled in parallel with other drugs in order to low down the infection. TNF-alpha, a cytokine targeted for the treatment of HS, does not represent the most important cytokine in the “cytokine storm” which characterizes COVID-19 spread but is surely useful to reduce the general inflammatory status (5). Furthermore, therapy suspension, in ADA treated HS patients, could worsen the skin and general inflammatory conditions and, once the biologic is reintroduced, it could enhance the production of anti-drug-antibodies and reduce or suppress the clinical response (loss of efficacy) (6). In conclusion, medical decision concerning suspension of therapy in biological treated HS patients has to be taken with great caution, paying attention to each single case.