skin or soft tissue infection
"My 17 year old son is allergic to sulfa based antibiotics (he gets hives everywhere), but he keeps getting staph infections (like boils) so this time he was given Cephalexin. He got through his whole 10 days of taking it twice daily, just finished last Thursday,  The negative side effects kicked in Saturday, Sunday & Monday. Stomach pain, chills, fever, tightness in chest, frequent urination, restlessness, anxiousness and sleeplessness. He's really freaked out about it. The inability to sleep is what's actually most upsetting because it makes you feel more anxious and crazy after a few days. The crappy thing is - he just has to wait and wait until it clears out of his system. Poor kid. This sucks."