Heheh. Musta been some fall he took----or was it six falls? The fact he didn't have the (ahem) Iowa injury taken care of on vacation is strange. Seems only logical he'd doctor an injury while on hiatus, to be fit for the campaign trail.
My theory is that Kerry is a very sick man. His pallor color looks unhealthy, his skin is sallow, and he's unusually gaunt looking. His eyes look very dark, and he seems like he's constantly wincing, as if he's in pain.....even before the so-called shoulder injury.
One of the Hepatituses, maybe? It was speculated above that there's an STD involved. Hepatitus problems would explain the liver not functioning fully - i.e. sallow color.