Chronic Chilblain Like Lesions Associated with the Covid-19 Pandemic

ABSTRACT

Background/Aims We report the features of chronic chilblain-like digital lesions newly presenting since the start of the covid-19 pandemic. Comparison with primary perniosis and acrocyanosis, reveals a unique phenotype which appears to be a long-covid phenomenon. Methods The case records of 26 patients with new onset persistent chilblain-like lesions presenting to the Rheumatology service of St George's University Hospital, London between Autumn 2020 and Spring 2022 were reviewed. Demographic and clinical features, serology, imaging, treatment response and outcome up to Summer 2022 were collated retrospectively. Results Chilblain-like lesions first occurred between September and March;2019/ 2020 6 cases, 2020/2021 18 cases and 2021/2022 2 cases. Mean age 35.4 (17-60) years, 88% female, 85% white, all non-smokers. Median body mass index (BMI) 20.2, range 17.0 - 33.2. BMI underweight (<18.5) in 27%. All cases reported new red-purple-blue colour changes of the fingers, some with pain, swelling and pruritis, affecting both hands in 12, one hand in 6, and both hands and feet in 8 cases. There was a past history of cold sensitivity or primary Raynaud's in 54%. Covid was confirmed in 3 cases, 2 - 8 months prior to onset of chilblain-like symptoms. Possible covid, unconfirmed, was suspected in 5 cases, 1 - 11 months earlier. Affected digits appeared diffusely erythro-cyanotic in 81%, with blotchy discrete maculo-papular erythematous lesions in 42%, some with both features. Involvement was asymmetric in 54%, thumbs spared in 69%. Complement was low in 50% (8/16), ANA positive in 26% (6/23). MRI of hands showed phalangeal bone marrow oedema in keeping with osteitis in 4 of 7 cases. More severe signs and symptoms were associated with low BMI, low C3/4 and a past history of cold sensitivity or Raynauds. Cold avoidance strategies were sufficient for 58%. Pain prompted a trial of NSAIDs, aspirin, nitrates, calcium channel blockers, hydroxychloroquine, oral or topical corticosteroid or topical tacrolimus in 42%. In general, these were minimally effective or not tolerated. 4 severe cases received sildenafil or tadalafil, effective in 2. In 27% complete remission occurred during the first summer season after symptoms commenced, median duration 6 (range 2 - 10) months. In the remaining 19 cases, chilblain-like symptoms returned or worsened in the subsequent second winter period, with 6 of 19 entering remission the following summer. For the remaining 13 persistent cases the total duration of symptoms spans more than a year, and in four cases more than 2 years. Conclusion This series illustrates a distinct chronic chilblain-like condition. Features similar to primary perniosis include female predominance, middle age, pruritic painful blotchy lesions, asymmetry and low BMI. Features in keeping with acrocyanosis include chronicity, extensive diffuse erythro-cyanotic discoloration, relative improvement in warm weather and lack of association with smoking.