I have a 5-inch Unicorn Tang in my marine store that unfortunately arrived with a fungal infection on his dorsal fin, tail fin and on top of his head, just between his eyes. The one on top of his head is whitish/semi transparent in colour and slightly cone shaped and the other fungus are white, fluffy blobs.
We quarantined him immediately in a tank having about 50 gallons containing a couple of medium size pieces of live rock to give him a refuse to hide behind if he feels the need to. As you know, it's all about eliminating any stress factors, even with healthy fish. He's still in quarantine now. Apart from the fungal problem he is really active, eats like a horse and has no other signs of damage or infections - his coloration is fine, eyes are bright, and appears perfect in every other way. We feed him on New Era high protein fish flakes and pellets including algae versions, which I think is one of the most nutritional marine foods available, in an effort to keep his immune system high.
I think this fungus might be Lymphocystis. As far as I'm aware this is not a treatable fungus but you may know different. We've tried to treat him with Esha Odinex, which is supposed to treat many different infections, just in case this fungus isn't Lymphocystis as I suspect it might be. So far nothing has worked.
Any help or even confirmation that I'm right about Lymphocystis being untreatable would be really helpful
Thanks for your email, and from what you say, tend to believe its Lymphocystis (Cauliflower or Nodule Disease). Since it's a virus, there are no known/proven cures. Nevertheless, there are some thoughts as to procedures that have shown some promise.
As you seem to already know, this is a stress-induced condition, and it's prudent to isolate the fish as you have done. Since it's eating well, it could very possibly correct the condition itself if not located in a stressfully small tank. Nevertheless, overly coated fin areas can be timed away with scissors to prevent the release of additional virons/Lymphocystis, then the remaining trimmed fin tissue edge swabbed with Tincture of Merthiolate or Mercurochrome twice a day for four days (let the treated areas dry for thirty seconds) and/or the use of a 10% stabilized solution of silver nitrate. My co-author, Lance Ichinotsubo, of our book 'Marine Fish Health and Feeding Handbook' also heard of treating affected areas with Visine®, which contains the active ingredient Tetrahydrozoline. However, that is still hearsay at this point in time. Its also reported that treatment with Ganciclovir, a drug used in the treatment of Herpes virus has shown some effectiveness, particularly at slowing the spread of Lymphocystis (Clifton, 1993). Lance has also experimented with Viractin®, a cold-sore remedy available over the counter, which seemed to work well. Also, and quite interesting and successful, he has used 35% hydrogen peroxide, at a dose of 1 ml/10 gallons to eliminate Lymphocystis from the fins of a Koran Angel!
If you decide to treat using any of the above comments, please let me know the results as I try to keep a log of all medical advice and their outcomes for helping hobbyists in the future.
Hope this helps,