It could be a filarial infection. The treatment that worked for me to get rid of my black fiber hair like worms was a combination of ivermectin 7 days on 3 days off for a few rounds 4 or 5 months worth and 9 weeks of doxycycline plus albendazole 25 days then a 2 week break for 3 or 4 rounds. It is hard to kill the adults and they will keep coming back if you don't kill the adults. the meds will steralize them for awhile but if you dont get rid of them they will start giving birth to the microfilaria.