Wolf's isotopic response: A case of dermatomal granuloma annulare after COVID-19 vaccination

The SARS-CoV-2 pandemic was announced in March 2020, with the first vaccines becoming available later that year. Although generally well tolerated, there have been reports of skin reactions occurring after receiving COVID-19 vaccines, with a rare occurrence of granuloma annulare. Granuloma annulare can occur secondarily to herpes zoster infection in a phenomenon known as Wolf's isotopic response (WIR). WIR has been described to often occur after herpes zoster virus infection, at the location of the healed shingles rash, termed 'post-herpetic isotopic response' (PHIR). We present the first reported case of PHIR with granuloma annulare after the Moderna COVID-19 vaccination series. This reported reaction should not limit receipt of the COVID-19 vaccine, but awareness of this association can minimise additional work-up and treatment.