I think they are usually depicted as bald, homey the clown can also be added to the list of bald clowns. BTW you can buy clown wigs, that have a bald spot and red fro on the sides. For example
http://www.buycostumes.com/Hairiscary-C ... 4Aodz1w_QA. http://www.google.com/imgres?um=1&hair loss=en ...