Flaking nails near nailbed

In several of my fingernails, upper "layers" are starting to separate from the nailbed about 1/4 inch above my cuticle.  Could this be the residue of an allergic reaction?  In February I developed red, dry, itchy, peeling palms and soles after taking 3 courses of Augmentin and 1 course of Levaquin to beat a persistent bronchial infection.  The doctor couldn't diagnose the rash (there were no blisters).  I am on 137mcg levothyroxin (levothyroxine) for hypothyroid, and my levels haven't been checked since September 2008.  I am recovered from the infection and otherwise ok except for controlled asthma.