key: cord-0969924-kzzckp6t
authors: Sriwijitalai, Won; Wiwanitkit, Viroj
title: COVID‐19 and favipiravir induce cutaneous adverse reactions: a difficulty in clinical dermatology practice
date: 2022-05-15
journal: Clin Exp Dermatol
DOI: 10.1111/ced.15202
sha: b772938ca82040ab0cf27f5d36c973d21701e53d
doc_id: 969924
cord_uid: kzzckp6t

There have been reports of skin rash developing in patients with COVID‐19 on favipiravir therapy, including a recent report in this journal. We report a patient who developed a maculopapular skin rash while taking favipiravir. [Image: see text]

Dear Editor, We read with interest the recent article by Punyaratabandhu and Vanitchpongphan in Clinical and Experimental Dermatology describing cutaneous adverse reactions (CARs) in patients with COVID-19 treated with favipiravir. 1 The authors stated that in such patients, medication allergy should be considered and excluded as a cause of the rash. 1 We agree with the authors that favipiravir can have CARs. A recent examination of the efficacy of favipiravir, lopinavir/ritonavir and arbidol found identical efficacy between the drugs, but a much higher rate of CAR with favipiravir. 2 However, such lesions were not generally subjected to specific pathological testing, and the likelihood of unfavourable consequences is based solely on speculation. A patient with COVID-19 may have a cutaneous issue despite receiving no treatment, 3, 4 and therefore other possible causes of rash, such as other medications, pre-existing personal sickness and concomitant medical problems must be excluded. There is a clinical challenge is distinguishing between skin rash caused by COVID-19 and that caused by favipiravir. Although a previous report 1 described careful exclusion of other causes of other concurrent factors, there was no confirmation by skin test.

We report a similar case, that of a 28-year-old woman who developed a maculopapular rash on her limbs (Fig. 1) , which began on Day 10 of a 2-week course of favipiravir 30 mg/kg/day for COVID-19 infection. The patient had previously been well and was not taking any other medication. A skin prick test for allergic reaction to favipiravir yielded a positive result.

Favipiravir was continued for the remaining 4 days (Days 11-14) of the 2-week course and the patient was also started on oral chlorpheniramine 12 mg/day. There was complete clearance following 7 days of chlorpheniramine (2 days after favipiravir therapy ceased), without post-inflammatory hyperpigmentation, but there was some skin exfoliation.

Our case is further confirmation that favipiravir can cause skin rash, and a specific allergy test is usually required for diagnosis. Such rashes pose a clinical challenge during favipiravir therapy for COVID-19, as such rashes can be due to the virus itself or to the medication prescribed to treat it.

Favipiravirinduced cutaneous adverse reactions in patients infected with COVID-19

Systematic review and meta-analysis of effectiveness and safety of favipiravir in the management of novel coronavirus (COVID-19) patients

Various forms of skin rash in COVID-19: petechial rash in a patient with COVID-19 infection

Cutaneous manifestations of COVID-19

The authors declare that they have no conflicts of interest.

None.

Ethics approval was not applicable. The patient has provided informed consent to publication of their case details and images.

Not applicable.