What Causes Painful Red Spots On Thighs?

VERY PAINFUL REDDISH huge spot on THIGH
Dear Doctor, I woke up one morning to little white pus filled seem to be pimples on both thighs then they started to disappear, I have stretch marks on my upper thighs now on my left thigh i have HUGE rash like red and very tender to touch bruised like spot and it is swollen. on my right thigh its just a pimple like bump thats swollen and very painful as well. its so painful i dont want to walk it hurts to even do that, i feel flu like symptoms. this is very painful and i just want to know what it could be? additional information... the stretch marks are swollen and red so i cant tell if its a bump or my actual stretch marks. i just know its PAINFUL!!!!