Parrolet losing feathers

Question
My friend has a parrolet that is continuously losing it's feathers.  You can see the bare skin.  It eats alot and acts healthy.  Took it to a vet - he gave it iodine, some other medicine (unsure of the name) and something to stop itching.  Does not seem to be contagious.  Vet doesn't know what is wrong.  Would appreciate any info you might have.

Answer
Hi, Terry.  Thanks for posting your question.

Was the bird seen by an avian veterinarian (a dog/cat vet won't work because they don't have avian knowledge)?  

I don't understand why the vet would prescribe medicines if s/he didn't know what was wrong (medical reasons...meds shouldn't be prescribed for no reason).  The only additional information I can offer is that sometimes parrots (a parrotlet is a parrot) pluck themselves for psychological reasons (boredom, stress, anxiety, environmental problems, not enough full spectrum lighting, not enough bathing, improper diet, not enough atention, other pets/people in the home aggravating the bird, etc.).  Each of these areas need to be investigated and ruled out by the process of elimination.  If this parrotlet is caged with other parrotlets/parrots (your statement "does not seem to be contagious" indicates to me that it is not spreading to other birds), perhaps another is overpreening this parrotlet or picking on the parrotlet.  This could be determined by where the parrotlet is losing the feathers, such as on top of it's head (the bird can't reach the top of it's head in order to pluck itself there, so another bird would have to be doing this).  Psychological problems are usually hard to overcome until the initial problem is known.  

Eating a lot doesn't matter...it's what it is eating that is important.  An improper diet can cause health issues, including feather problems.  If the bird isn't bathing regularly, doesn't have full spectrum lighting, etc., this could also be the problem.  

Chrys