Thank you for your question.
First, I would like to say that the best option for you is to discuss this with your doctor, or another trained health professional. Without seeing the rash, and without having access to your medical file makes it very difficult to answer your question adequately.
Nonetheless, from your description, there are two diagnoses that come to mind: shingles and herpes. Both can present as a slightly elongated cluster of vesicles on an erythematous (red and rash-like) background near the coccyx/genitals. The best way to confirm which of these infections is present (if indeed there is an infection) is to get tested specifically for HSV (herpes simplex virus) and varicella zoster (shingles). Herpes virus 1 tends to affect the buccal mucosa (mouth and lips, e.g, cold sores), while herpes simplex 2 generally affects the genitals. However, both can also infect the anus, buttocks, top of the thighs. Your coccyx (tail bone) could be the only area affected, and this does not mean you don’t have herpes. You should probably get tested for both HSV1 and HSV2. These blood tests are routinely performed if there is suspicion of either of these conditions, but most doctors do not necessarily perform these tests if there is no specific indication. You should therefore ask your physician if these tests were performed in the past. Also, if the test was performed within 6-8 weeks of the rash, a negative result does not exclude herpes.
In terms of genital herpes, the initial episode can last for more than 20 days and it is often associated with generalized symptoms, such as fever, aches and pains, swollen lymph nodes. For others, the initial infection can be mild with minimal symptoms.
Some people do not experience symptomatic recurrences but for those who do, recurrences are usually shorter and less severe than the initial episode. Recurrences are usually preceded by tingling, itching, burning or pain.
Approximately 80% of persons having a first episode caused by HSV-2 will have at least one recurrence, while only 50% of persons with HSV-1 will experience a recurrence. The most common scenario is occasional recurrences (about 4 attacks per year).
It may also be important for you to know that up to 60% of people who have genital HSV infection show no signs of the disease and are unaware that they are infected. These people are, however, capable of transmitting the virus to others.
If indeed, the diagnosis is confirmed by blood tests, there are a few things you can do to prevent recurrences: avoid physical or psychological triggers, use salt baths for the genital area, wear loose underwear. Antivirals can also help. However, antivirals only works while you are taking it, i.e. they do not cure the disease, and they may not prevent relapses in some cases either, though they do shorten the duration of a genital herpes outbreak and help speed healing. Also, it is definitely possible to get a corneal (the superficial lining of your eye) infection with Herpes simplex virus. This can damage your cornea irreversibly if diagnosed too late. Therefore, strict hygiene is advised in a herpes recurrence to prevent infection elsewhere.
Finally, by avoiding sex when the signs of herpes are present, and by using condoms with sexual partners between outbreaks, the chance of passing on herpes may be reduced.
However, all this advice does not apply if you don’t have herpes. Herpes is very common in the adult population, with some authors suggesting it can affect 1 in 6 individuals. I would strongly recommend you get tested and therefore get appropriate treatment if there is indeed the presence of an infection,
Good luck, and don’t hesitate to contact us again if you have other questions,
Vi, for AlterHeros