An allergic reaction, to what is though may be, either lack of sleep, too much alcohol, or sleeping around with too many different girls.
Since his LeakyWrinkleEye, he has covered it up using a pirate patch, which led to his obsession with pirates. He dresses up as 'the clown pirate' on the rock steady live tour.
Also, he ingaged in dreams of having his own pirate store, or cafe. Where they would sell chocolate gold coins, and treasure chests.