Patients are randomized to receive either rhNGF at one of two doses or placebo, administered subcutaneously twice weekly for 18 weeks. Patients are stratified into three groups within their regimens by use of didanosine, zalcitabine, or stavudine as follows: current use vs. discontinued between 8 and 26 weeks before randomization vs. never used or discontinued use at least 26 weeks before randomization. Patients will assess their pain daily using the Gracely Pain Scale. AS PER AMENDMENT 5/6/97: After completion of the double-blind phase (18 weeks on treatment followed by 4 weeks off treatment), patients may receive open-label, active drug treatment according to their previously assigned regimen for an additional 48 weeks.