Hi, Zicam is Oxymetazoline, acts as an nasal decongestant which can dehydrate the mucus membranes in nasal passages that puts an end to symptoms like a runny nose, watery eyes, sneezing etc. But, they tend to dry up the mucus membranes in vagina as well which can lead to develop vaginal infection. So, Zicam has no direct effects on developing vaginal infection or vaginal but it may aggravate vaginal infection that has already mentioned. Passing of light grayish greenish vaginal discharge with fishy odour seems to be trichomoniasis. You may suffer from trichomoniasis caused me by protozoan parasite named trichomonas vaginalis. Though it is always believed to be a sexually transmitted disease but, nonsexual transmission of trichomoniasis can occur through formites like towels, toilet seats, from swimming pools or sharing sex toys without using a new condom etc. Even in women, trichomonas organisms can live in vagina for many years without showing any clinical features. You can undergo some investigations like urine R/M/E & C/S, vaginal swab for C/S to exclude the causes. Metronidazole is the treatment of choice for trichomoniasis. Take care. Hope you have received your answer. Let me know if I can assist you further. Regards, Dr. Zubayer Alam, General Medicine & Family Physician .