Have a patient complaining of respiratory symptoms including cough, sinus congestion, rhinorrhea, sore throat, etc…? Have symptoms been lingering for over 10 days? Ask if they are having actual fatigue as well. If so, consider Mycloplasma as the causative organism. This is an atypical organism, therefore penicillin and cephalosporins would have no effect. You need to treat these patients with azithromycin or doxycycline instead.
Often times these patients will have been on amoxicillin, cephalexin, cefdinir, etc… and return to you with no improvement. Atypical organisms also can cause non specific and bizarre symptoms. I had a pregnant patient once who was complaining of nausea, vomiting, diarrhea and cough. I tested her for Mycloplasma and lo and behold it was positive. I started her on azithromycin and she was better in 24 hours.
Fatigue with common URI symptoms? Think Mycloplasma. Start them on azithromycin or doxycycline instead!