What is happening to my 4 1/2 year old son?

My normal, healthy, friendly, intelligent 4 1/2 yr old son has been having excessive behavioral issues this week.
I started noticing an issue with him last month. He started to complain about "having a drip" in his underwear. I would check the problem daily and no wetness would be present. This would usually occur after using the bathroom.We had several bad days of this, which included much frustraion. I took him to our Family Dr to rule out any kind of infection. His obsession with "the drip" is lesser, but still comes up daily.
Starting this Mon after School, he is talking excessively about "being stinky" and getting everything he comes in contact with or is near "stinky". He holds his arms out and figits with his hands and fingers almost constantly. "I think I got the toy stinky", "I think I got that stinky" I think I got this stinky"... When he speaks to me, it's very fast, he says Umm alot and I cannot get him to stop talking until he has finished his thought compleatly. He goes to PreK in the mornings and I spoke with his teacher about it. She noticed the same issues with him and it had gotten more extreme by Wed. I took him to the Dr and she asked him many questions to rule out any brain injury. We go back next week.
ALL day today (Thurs), he won't swallow his saliva like normal. He lets it pool in his mouth until it is either falling out or I tell him to swallow or he'll finally swallow but has to tell me about it everytime. He speaks mumbly since he is stressing with his bottom lip.  The "stinky" issue continues, allong with the now "slime" (saliva) issue.
~What is happening to him that is causing this excessive talking about stinky, slimey, wet, drippy things, playing with his hands, figiting and excess saliva?? Help!!

[Kevin Kennedy, Ph.D.]

Children this age sometimes exhibit symptoms that are typical of obsessive-compulsive disorder, but the symptoms fade away just like they appeared. For some children it marks the onset of an actual obsessive-compulsive disorder. Is there any family history of anxiety? One condition to rule out is Pediatric Autoimmune Neuropsychiatric Disorders Assciaited with Streptococcal Infections. These conditions are marked by sudden-onset obsessive-compulsive-type symptoms, and the condition occurs in the wake of a strep infection such as Scarlet Fever or so-called strep throat. If the strep infection is still present, treatment with antibiotics is necessary. If there is no cureent infection, treatment with antibiotics generally doesn't help, but the symptoms will wane.

[jillyfish75]

Thank You for you insight. He was tested for strep in the Dr. office, which was negative. It is being sent out to a lab to confirm. Anxiety doesn't really run in the Family, though I'm not going to rule that out. I'm worried that perhaps all the talk of avoiding germs in the past 6 weeks may have brought this on. His class covered waching hands thoroughly in School and I have been applying antibacterial gel and using hand wipes on shopping carts whenever we go shopping.
Is the saliva issue common along with these symptoms or could it be another medical issue completely?
Bi-Polar does run in my Family. My Great Grandmother, Grandmother, 3 Great-Aunts, one Uncle and one First-Cousin all had/have it to some degree. Could my Sons symptoms be pointing in that direction?

[Kevin Kennedy, Ph.D.]

One of the unfortunate unintended effects of the current steps to enhance hygiene in the face of the H1N1 virus is that some children become overly fearful of (and preoccupied with) 'germs'. For anxious children this can pose a particulalr challenge. The saliva issue is not unusual and is one manifestation of their concern about contamination. If this does not subside in a few weeks it would be good to arrange an evaluation.