I have a cat that has been tearing her own hair out and scratching like a meth addict with bugs under his skin.  Last year we had a little bout with fleas when a neighbor treated their yard (even though the cat never goes outside).  I tried about $300 in sprays, bombs, and flea treatments.  None of them did shit until I got a flea collar for the cat.  They disappeared and never came back.  They were even immune to the high dollar squirt treatments.  

Well, fall is here and she's doing it again.  The only problem is I've kept a fresh collar on her and checked her fur thoroughly for bugs, bites, scaly skin, or any other signs of infestation or skin problems.  And I haven't found a single thing.  I haven't changed her diet or brought in any foreign chemicals like laundry detergents or cleaning supplies.  

I haven't noticed any problems with lethargy, eating, or drinking so I am at a loss as to how to treat her.  I can't afford a vet trip or expensive treatments right now so does anyone know what the cause may be and an inexpensive remedy?

One of my friends had a cat that was very allergic to dust mites and dogs, and would scratch until it bled.  Keeping it away from dogs is easy, dust mites... not so much.  Antihistamines and cortisone were needed.

I would try giving the cat the appropriate dosage of benedryl three times daily for a week, and see what happens.  If that helps significantly, then you know it's allergies, and you can start the hunt for what is causing it.

That's a good way to lose a finger with this one.  She tagged me good just putting on the new flea collar.

Crush the meds up in some soft food or something the cat likes to eat. Mix it in well and the cat won't know.