White House press secretary Karoline Leavitt said he knocked his hand on the corner of a table during the signing. Leavitt had earlier blamed previous marks on "constantly working and shaking hands all day every day." Observers also noted heavy makeup on one hand after a past bruise, seemingly to hide discoloration.
Harvard Health confirms low-dose aspirin can increase susceptibility to bruising. Dr. Deepak Bhatt explained aspirin reduces platelet clumping, so bleeding and under-skin bruises may be more likely; he also noted gums may bleed more when flossing and suggested electric toothbrushes or shavers to reduce bleeding.