To assess the efficacy, safety, and tolerability of recombinant human nerve growth factor ( rhNGF ) in the treatment of HIV-associated sensory neuropathy. AS PER AMENDMENT 5/6/97: To compare the change in viral load between the double-blind phase baseline and week 4 in placebo and active rhNGF recipients. To ensure that rhNGF does not induce an increase in viral load compared with viral load changes seen with placebo.