Interesting. Legally, no: here at least, the acts of making and distributing the photos is the same crime; had the subject not been underage, there would be no crime involved at all. (It might be deemed a breach of copyright, for which you could theoretically sue, but that's all.)
Perhaps we need a sort of 'Romeo and Juliet' exemption, like some US states have so two 15 year olds having sex isn't a crime even if the 15 year old having sex with a 20 year old would be. In fact, I think we currently have - in the UK - the absurd anomaly where I could have sex with a 17 year old girl quite legally - but you taking a photo of that perfectly legal act would make you a sex offender. I can't imagine politicians putting any effort into any sort of rethink, though: too easy to be attacked for it.