COVID‐19 and skin diseases: results from a survey of 843 patients with atopic dermatitis, psoriasis, vitiligo and chronic urticaria

The inflammation elicited by COVID-19 can influence the skin microenvironment.1-3 Notably, the course of dermatological conditions can be affected by both COVID-19 and its treatment.4 To date, limited information is available regarding the influence of COVID-19 and its treatments on the course of cutaneous diseases and vice versa. We conducted an electronic survey to evaluate acute COVID-19 symptoms, treatment, and changes in the clinical manifestations of psoriasis, vitiligo, atopic dermatitis (AD) and chronic urticaria (CU) in Brazil. Between May and June-2021, participants were recruited through 88,648 SMS messages and online support groups for the aforementioned diseases to answer an online questionnaire regarding COVID-19 and these skin diseases. A total of 6614 confirmed COVID-19 cases were analysed. Of these, 843 reported one of the four active skin diseases. Hospitalization due to COVID-19 did not differ between respondents with (9%) and without (11%) skin diseases (P = 0.168). The results concerning the clinical course of the dermatoses are presented in Table 1. CU and arthralgia in psoriasis were the conditions most severely influenced by COVID-19; however, the clinical courses of the dermatoses were not associated with hospitalization due to COVID-19. Regarding symptoms reported during COVID-19, high fever was associated with the exacerbation of CU. Severe dyspnoea was associated with the worsening of arthralgia in psoriasis and AD lesions. The use of antimalarials for COVID-19 was associated with the exacerbation of vitiligo, but neither corticosteroids, anticoagulants nor antimicrobials (for the treatment of COVID-19) were associated with modifications in the clinical course of the dermatoses. Antimalarials for COVID-19‡ The associations among specific dermatological treatments and COVID-19 severity, symptomatic period and clinical course are presented in Table 2. A lower rate of hospitalization was identified for respondents with vitiligo who used oral antioxidants (e.g. vitamin E, vitamin C or Polypodium leucotomos) than controls. Oral corticosteroids for the treatment of vitiligo and CU led to greater clinical impairment, as did the use of antihistamines for AD. Antihistamines for dermatological diseases were associated with a longer symptomatic period in cases of acute COVID-19. Systemic therapies, such as methotrexate and biologics (for AD, psoriasis and CU), did not exhibit a detectable effect on COVID-19. Specific treatment Odds ratio (CI 95%)† Odds ratio (CI 95%)‡ Odds ratio (CI 95%)‡ AD may be aggravated or complicated by viral infections.5 IL-13 levels are elevated in individuals with severe COVID-19, especially among patients who require mechanical ventilation.6 This fact may explain the worsening of AD lesions reported by respondents with severe dyspnoea in our study. Disease flares were identified in about one quarter of patients with psoriasis following COVID-19.7 The exacerbation of arthralgia in psoriasis patients was noteworthy and may be explained by the elevation of TNF-α and IL-17 in the cytokine storm of COVID-19.8 Hydroxychloroquine was associated with clinical worsening of vitiligo. Actually, antimalarials are oxidative drugs whose additional stress on melanocytes in situations under oxidative stress, such as COVID-19, can influence active vitiligo.9 Oral glucocorticoids are used in cases of unstable vitiligo and CU, which can indicate a disease more susceptible to exacerbation induced by viral infection. The worsening clinical course of CU during acute COVID-19 may be the result of TGF-β secretion during this infection, which induces clinical manifestations such as fatigue, fever, cough, pneumonia and the loss of olfactory sense. The exacerbation of CU was also associated with high fever. IL-6 is an acute-phase protein that is often secreted in patients with COVID-19; it is one of the cytokines that mediate the systemic response to inflammation and its symptoms, like fever, which may be involved in this association.10 In conclusion, the severity of COVID-19 does not differ among patients with AD, CU, psoriasis and vitiligo, but acute COVID-19 and its treatments can affect the course of skin diseases. None to declare. None.