Expert recommendations for the management of autoimmune bullous diseases during the COVID-19 pandemic.

Editor

Autoimmune bullous diseases (AIBDs) are potentially life‐threatening disorders comprising intra‐epidermal/epithelial (pemphigus) and sub‐epidermal/epithelial blistering diseases (pemphigoid and dermatitis herpetiformis). Corticosteroids and non‐steroid immunomodulatory agents are the mainstays of treatment. Treatment can be challenging particularly in pemphigus, mucous membrane pemphigoid and epidermolysis bullosa acquisita which may require more intense immunosuppressive approaches. ,

A novel coronavirus named severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) is responsible for the recent worldwide coronavirus disease 2019 (COVID‐19) pandemic. Since immunosuppressive therapy can generally inhibit antiviral immunity, patients with AIBDs undergoing immunomodulatory treatment, especially elderly patients with comorbidities, may be at higher risk of worse outcomes should they develop COVID‐19. On the other hand, it has been postulated that immune system over‐activation is responsible for the lung injury caused by SARS‐CoV‐2 and that a subgroup of patients might actually benefit from immunosuppressive drugs.

Similar to a recent publication concerning atopic dermatitis, a panel of AIBD experts from different academic centres addressed questions regarding COVID‐19 and the use of common immunomodulators (corticosteroids, azathioprine, mycophenolate mofetil/sodium, cyclophosphamide, methotrexate, cyclosporine, dapsone/sulphapyridine, doxycycline/tetracycline, colchicine, rituximab, high‐dose intravenous immunoglobulins [IVIG] and immunoadsorption/plasmapheresis) in patients with AIBDs.

What do we recommend for AIBD patients treated with immunomodulating therapy during the SARS‐CoV‐2 pandemic?

Maintain immunomodulatory therapy when needed since unjustified withdrawal could lead to uncontrolled AIBD activity associated with high morbidity and mortality. ,

Adhere to the advice from local health authorities in each country.

Follow standard precautions including social distancing and hygienic procedures.

What considerations should be made regarding immunomodulating therapy in SARS‐CoV‐2‐infected patients with AIBDs?

Patients with confirmed COVID‐19 should initially undergo risk evaluation.

Azathioprine, mycophenolate mofetil/sodium, cyclophosphamide, methotrexate and cyclosporine may be stopped for the duration of COVID‐19 symptoms, whereas topical corticosteroids, prednis(ol)one ≤10 mg/day, dapsone/sulphapyridine, doxycycline/tetracycline, colchicine and IVIG can be continued.

Prednis(ol)one >10 mg/day may be reduced depending on the activity/severity of the AIBD, age, comorbidities and severity of COVID‐19 in collaboration between the dermatologist and physician in charge of COVID‐19.

Abrupt termination or considerable dose reduction of systemic corticosteroids should be avoided, particularly in patients with severe forms of AIBDs. Of note, there is some evidence that prednis(ol)one may potentially have beneficial impacts on COVID‐19.

Can we predict interactions of AIBDs, its complications and immunomodulating therapies with COVID‐19?

Patients with AIBDs on immunosuppressive therapies are generally prone to develop opportunistic infections including viral infections, and microbial pathogens may potentially in turn trigger the bullous disease. Of note, both pemphigus and pemphigoid are associated with increased risk of death due to pneumonia and, in the case of paraneoplastic pemphigus, bronchiolitis obliterans. , However, there is currently little information specifically pertaining to SARS‐CoV‐2 and AIBDs.

Dapsone/sulphapyridine, doxycycline/tetracycline or IVIG are usually not considered to increase the risk for infections and may even decrease the risk of some infections, thus may be preferred in the COVID‐19 pandemic where applicable.

AIBD patients treated with rituximab were reported to have no additional risks for infections over high‐dose corticosteroids without rituximab in general. However, since long‐lived SARS‐CoV‐2‐specific plasma cells are not expected to be present in most individuals, AIBD patients treated with rituximab within the last 1 year may have a more severe/prolonged COVID‐19 infection compared to healthy persons.

Initiation of rituximab or immunoadsorption/plasmapheresis in patients with AIBDs must be weighed against the risks of conventional immunomodulatory regimens.

Finally, it is advised to remain updated through the WHO/CDC homepage (www.who.int, www.cdc.gov). Recommendations directed to AIBD patients and their families during the COVID‐19 pandemic have been recently released by the European Academy of Dermatology and Venereology (www.eadv.org/covid‐19/task‐force).

Funding sources: none.