Management of patients with hidradenitis suppurativa during the COVID-19 pandemic.

Dear Editor,

The recent coronavirus disease 2019 (COVID‐19) pandemic, caused by the Severe acute respiratory syndrome‐associated coronavirus type 2 (SARS‐CoV‐2) virus, has spread all over the world. As of April 21, 2020, there were 2 478 948 cases of infection, of which 652 046 have resolved, and 170 399 people have died in 185 different countries. The elderly and people with underlying conditions such as cardiovascular disease, obesity, diabetes or cancer are at the highest risk of infection and prone to serious outcomes.

Hidradenitis suppurativa (HS) is a chronic, recurrent, debilitating autoinflammatory skin disease characterized by disfiguring nodules, abscesses and suppurating lesions. Adults and children with HS are at higher risk of cutaneous, extracutaneous and systemic infections, at even higher rates than in patients with psoriasis and atopic dermatitis, which leads to increased mortality. A recent publication also noted that compared to a placebo, HS patients treated with adalimumab may be at a moderately higher risk of general infections and nasopharyngitis. Moreover, HS and COVID‐19 share many negative prognostic factors such as cardiovascular disease, obesity and diabetes. , However, it is controversial whether or not HS patients are particularly susceptible to COVID‐19.

HS patients are frequently treated with immunosuppressive drugs, based on the inhibition of specific molecular or cellular targets such as tumor necrosis factor alpha (TNF‐α), interleukin (IL)‐1β, IL‐10, and the IL‐23/T‐helper (Th) 17 and IL12/Th1 axes. In the most severe COVID‐19 cases, the infection is probably associated with a cytokine storm, which is characterized by increased plasma concentrations of several ILs, including IL‐6, IL‐10, and TNF‐α. In this way, adalimumab and other biologics used in HS patients that block some of these pathways might play a protective role against COVID‐19. Some recommendations regarding biological treatment for psoriatic patients during the COVID‐19 pandemic have been reported. , Most of them suggest not stopping immunosuppressive drugs as patients might develop anti‐drug antibodies and an increased rate of disease flare might occur. Moreover, a recent publication describes a good COVID‐19 clinical course in four psoriatic patients treated with biologic drugs.

Although there are no reports on HS treatment during the COVID‐19 pandemic or a previous coronavirus epidemic, the guidelines do not recommend stopping treatment due to potential infection risks in the community. Furthermore, patients being treated with anti‐TNF‐α drugs have a similar risk of infection as the general population during seasonal influenza and H1N1 influenza. Therefore, while there is no evidence that biologics increase the risk or morbidity of a COVID‐19 infection, we should not recommend preventively discontinuing these medications. We propose close monitoring of HS patients and assessment of their comorbidities, age, conditions and specific situation to decide on a case‐by‐case basis. Besides, the most important recommendations to prevent infection are frequent hand washing, avoiding touching the face with unwashed hands and avoiding close contact with people.

Our decisions should be made based on evidence. Obviously, in a life‐threatening situation, HS would become a secondary concern. Nevertheless, we should not forget that HS is a severe disease with a great impact on patients' life. Stopping effective treatment might have unnecessary risks of aggravating the disease. All comorbidities should be considered when assessing our HS patients while waiting for specific data concerning the risk of COVID‐19 infection in HS patients.