Sweet‐like syndrome and multiple COVID arm syndrome following COVID‐19 vaccines: ‘specific’ patterns in a series of 192 patients

The two clinico‐pathological patterns are ‘Sweet‐like syndrome’ and ‘Multiple COVID‐Arm’. ‘Sweet‐like syndrome’ presents clinically as erythematous and oedematous papules or plaques, sometimes developing vesiculation or bullae. Histology shows classical Sweet syndrome with a diffuse dermal neutrophilic infiltrate, or an infiltrate of histiocyte‐like immature myeloid cells consistent with a histiocytoid Sweet syndrome. ‘Multiple COVID‐arm’ is characterized by multiple large inflammatory plaques with histological analyses showing a perivascular and interstitial inflammatory infiltrate with eosinophils.