Experience in patients with hidradenitis suppurativa and COVID-19 symptoms

To the Editor: We read with interest the letter written by Seltzer et al¹ about the risk of severe forms of coronavirus disease 2019 (COVID-19) in patients with hidradenitis suppurativa (HS) and would like to share our experience.

COVID-19 is an illness caused by severe acute respiratory syndrome coronavirus 2, which has spread quickly across the globe. This disease has a variable severity spectrum. A severe form develops in a subgroup of patients (especially elderly people and patients with underlying medical comorbidities) characterized by interstitial pneumonia, acute respiratory distress syndrome, and septic shock. HS is a chronic and recurring pathology of the pilosebaceous follicle. It is usually associated with several comorbidities, including obesity, smoking, diabetes mellitus, and cardiovascular pathology, among others, that, at the same time, are risk factors for the development of severe forms of COVID-19.^{1 , 2}

To assess the severity of COVID-19 in HS patients, we reviewed the medical records of the 75 patients with HS who were monitored in our center from February 15 to April 15, 2020. The data were collected directly from the electronic medical record. Verification of data was made by telephone contact with the 75 patients with HS.

Of the 75 patients with HS, 12 received biologic treatment, 30 were treated with nonbiologic systemic drugs, and 33 underwent topical treatment. Data highly suggestive of COVID-19 infection were present in 8 patients, including at least 1 of the following: symptoms of febrile acute respiratory infection, anosmia, ageusia, and compatible analytic or radiographic changes. None of them were tested for diagnostic confirmation, because only those patients who required hospital admission were tested at our center during this time frame. We collected some data from these 8 patients, which are summarized in Table I . We must specify that, according to the protocol of our center, unilobar pneumonia was not considered a severe form of COVID-19.

Table I.

Data of patients with hidradenitis suppurativa with symptoms suggestive of COVID-19

Variable	Patient 1	Patient 2	Patient 3	Patient 4	Patient 5	Patient 6	Patient 7	Patient 8
Age, y	60	32	30	69	50	37	21	53
Suggestive data of COVID-19	Febrile acute respiratory infection	Febrile acute respiratory infection and anosmia	Febrile acute respiratory infection	Febrile acute respiratory infection	Febril acute respiratory infection, ageusia and anosmia	Febril acute respiratory infection	Febril acute respiratory infection	Febril acute respiratory infection and compatible radiographic changes
Close contact with confirmed COVID + patient	No	No	No	Yes	No	Yes	No	No
COVID-19 risk factors	Age, AH, DM, DL, smoking	No	No	Age, AH, DL, IHD, COPD, smoking, obesity	AH, DM, obesity	NO	NO	AH, smoking
Treatment received	Clindamycin 300 mg/12 h	Doxycycline 200 mg/24 h	Ethinylestradiol/levonorgestrel 150/30 mcg/24 h	Clindamycin 300 mg/12 h	Adalimumab, 40 mg/7d	Doxycycline, 200 mg/24 h	Acitretin, 10 mg/24 h	Adalimumab, 40 mg/7 d
First date symptoms	4/6/2020	3/21/2020	2/25/2020	3/25/2020	3/18/2020	3/26/2020	3/13/2020	3/27/2020
End date symptoms	4/20/2020	4/17/2020	2/28/2020	4/03/2020	4/16/2020	4/8/2020	3/23/2020	3/31/2020
Pneumonia	No	No	No	No	No	No	No	Yes, unilobar
Hospitalization	No	No	No	No	No	No	No	No

AH, Arterial hypertension; COPD, chronic obstructive pulmonary disease; COVID-19, coronavirus disease 2019; DM, diabetes mellitus; DL, dyslipidemia; IHD, ischemic heart disease.

Regarding treatment, we highlight that there does not seem to be an increased risk of severe COVID-19 infection in our 2 patients with biologic treatment, but the sample size is too small for generalizability. In any case, following the evidence available to date, the current recommendation would be not to withdraw the biologic treatment in patients with HS who present with symptoms of COVID-19 as in other immune-mediated skin pathologies such as psoriasis.3, 4, 5

We are aware of the limitations of this study, including the small sample size, the absence of statistical analysis, and the lack of serologies or molecular research to confirm the diagnosis of COVID-19 infection. However, the main interest of this work is that in a population area of the southeast of Madrid very widely affected by the pandemic (with 2176 confirmed severe cases during this period), we observe that there have not been any severe cases within a series of 75 patients with HS, even when these pathologies share risk factors, regardless of the treatment they receive.