Genital herpes – Diagnosis and treatment
Herpes simplex virus (HSV) types 1 and 2 infections can be diagnosed based on the appearance of lesions (if present), as well as with laboratory tests. In general, though, if you do not have symptoms, there is no need for you to have any diagnostic testing for HSV type 1, which causes cold sores. If you may have been exposed to HSV type 2, a sexually transmitted disease that causes genital sores, you may need to be tested even if you do not have lesions.
Both HSV-1 and HSV-2 can cause visible skin lesions. Because such lesions can also be the result of other illnesses, it is really important that you see a doctor, especially if you’ve never had an outbreak before. Once you’ve had herpes, you can learn to recognize the lesions in case you experience recurrences. But if you have worse recurrences or if the lesions look different than usual, then you should see a doctor.
If you or your child experiences pain or tingling around or inside the mouth or on the tongue, you can feel and look for bumps and blisters around the painful area, which may indicate HSV-1.
If you have symptoms of HSV type 1 or 2, your doctor can diagnose a herpes infection by looking at your skin and/or by swabbing the sores to test for evidence of the herpes virus. If you do not have obvious symptoms, a blood test can help determine whether you have an infection.
Herpes Blood Tests
You form antibodies when you need to fight an infection, and antibodies can last for years or even a lifetime. Generally, it takes about one to two weeks for your body to produce detectable antibodies against herpes virus infection. The presence of antibodies is evidence that your body has confronted an infection, either recently or in the past.If you have a reinfection, antibody tests are not helpful because once you have the antibodies, they stay in your blood even when the virus becomes dormant.
- Type-specific herpes blood tests look for not only whether you have antibodies against a herpes virus, but also for whether the antibodies are against HSV-1 or HSV-2. Type-specific testing will not tell you where your herpes infection is located in your body.
- General herpes blood tests look only for whether you have antibodies against any type of herpes, and they do not specify whether you have antibodies to HSV-1 or HSV-2.
There are several different brands of blood tests that are used to detect viral proteins, and there are pros and cons of each. It is difficult to know how long it takes for blood tests to become positive after infection with HSV-1. The median time from the onset of symptoms to a positive HSV-2 blood test is as follows:
- HerpeSelect ELISA: 3 to 4 weeks
- Western blot: 3 to 6 months
- Kalon ELISA: 120 days
- Focus ELISA: 21 days
In general, it usually takes around two weeks for symptoms to appear after you have been infected with HSV type 1 or 2. If you do not have lesions that can be swab tested, is a good idea to wait at least a month or two before getting an HSV-2 test after a potential exposure. This is because it takes time for your body to make antibodies that can be detected in the blood. Testing before these antibodies are present can lead to a false-negative result.
There is also some possibility that herpes blood tests may detect antibodies to similar viruses through cross-reaction. This result would lead to a false-positive result, suggesting you have the infection when you don’t.
If you have a strong reason to believe that you have been infected, you might want to consider getting retested after six months because some of the tests take longer to become positive.
The diagnosis of neonatal herpes is challenging. Generally, babies are not screened for herpes infection. Symptoms such as lesions around the mouth or eye may alert caregivers that there is a problem. This should prompt diagnostic testing, which can be done using a swab sample. However, more complicated neonatal herpes infections, such as encephalitis (infection of the brain), require more specific tests such as a lumbar puncture.
There are a few other conditions can be confused with cold sores or genital herpes. Some of these conditions are quite serious, and it is not safe for you to self-diagnose. Typically, these conditions can be distinguished from herpes with a medical examination or with laboratory tests.
- Canker sores: Canker sores are usually red, raised sores with a painful, raw, whitish pit in the center. They may be present in the mouth, and they tend to occur as a result of oral trauma. The initial painful sensation of canker sores and cold sores is similar, but the lesions look different, and canker sores do not test positive for herpes simplex virus.
- Syphilis: A sexually transmitted disease that produces painless genital sores, syphilis can be confused with herpes. Your doctor may be able to tell the difference by visually inspecting the lesions. If you have syphilis, your blood tests should be positive for Treponema pallidum, the bacteria that causes syphilis infection; they would be positive for HSV if herpes is the cause of your genital lesions.
- Medication reaction: Medications can cause allergies and sensitivity reactions, which may manifest as a rash. This is not generally common in the genital area, but a medication-induced rash is not uncommon around the lips and mouth.
- Cancer/pre-cancer: Lesions in and around the genital area can be signs of cancer. The appearance of cancerous or pre-cancerous lesions should not have the blisters that often are present with HSV induced lesions. But if your doctor needs to distinguish between cancer and herpes, a swab or a needle biopsy (sample of the lesion) can differentiate the two concerns.
- Concurrent HSV-1 and HSV-2: If you have HSV-1 or HSV-2, you can also become infected with the other. These are different viruses and having one of them does not cause or prevent the other. It is important to keep that in mind and to see your doctor if you develop sores in a new location because they could be herpes or a different condition.