itchy white bumps on underside of penis

recently after having sex with my wife, a day later, i developed some white itchy bumps on the underside of my penis and the head of my penis. they only seem to get itchy in the morning or before bed. i have only ever had one sexual partner in my life, so i'm 100% sure its not an STD. just wondering if maybe it is a yeast infection or maybe eczema? i put some gentian violet on it, thinking it was a yeast infection. i then began putting some hydrocortizone cream on the underside of my penis. i found that the hydrocortizone cream is working, i would just like to be a little more confident this is the problem.
i have had these itchy white bumps for about 3 days as of today 11/25/2008 and have never had anything like them before.
thanks for any help

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