Introduction
Previous reports associate lichen planus (LP) eruptions with viral infection. Possible surge of LP is reported with COVID-19. We present the first case of COVID-19 associated LP in the presence of eosinophilia.
Case Description
A 24-year old female with a history of atopic eczema and mild intermittent asthma since childhood presented with an itchy rash on her hands and toes. The rash had commenced a few months prior and was associated with concurrent flu-like symptoms. She was not tested for COVID-19. Elimination of potential allergens did not result in symptom resolution. Physical exam revealed a macular, dusky, asymmetric and mostly pruritic rash. Laboratory data revealed new onset of peripheral eosinophilia and lack of coagulopathy. COVID antibodies were positive. A clotrimazole-betamethasone regimen proved ineffective. Subsequent biopsy showed LP with eosinophils. Topical steroids resolved the pruritus, and the lesions are healing.
Discussion
Following reports associating LP with viral infection, a lichenoid eruption in tandem with COVID-19 symptoms and a subsequent positive antibody test promotes a possible association between LP and COVID-19. Eosinophils are rare in LP with exception of hypertrophic LP which favors the lower extremities. While COVID-19 often presents with eosinopenia, our patient’s eosinophilia merits further investigation. This is particularly true in the context of preclinical studies arguing that eosinophils have antiviral functions. A possible association between LP and COVID-19 would also be an important addition to diagnostic differentials, especially among multiple reports of painful yet non-pruritic chilblain eruptions in the same location.