Herpes simplex virus (HSV) types 1 and 2 can be diagnosed based on the appearance of lesions (if present), as well as with laboratory tests. Show
In general, if you do not have symptoms, there is no need for you to have any diagnostic testing for HSV type 1—the type that causes cold sores. However, if you may have been exposed to HSV type 2—a sexually transmitted disease (STD) that causes genital sores—you may need to be tested even if you do not have lesions. Illustration by VerywellSelf-ChecksBoth HSV-1 and HSV-2 can cause visible skin lesions. It is important that you see a healthcare provider, especially if you've never had an outbreak before. Once you've had herpes, you can learn to recognize recurrences of the lesions. But if your recurrences are more severe or if the lesions look different than usual, then you should seek an evaluation. Herpes outbreaks usually appear as one or more blisters in clusters. The blisters may break open to become sores. Cold sores in the mouth are usually caused by HSV 1, and genital herpes infections are usually caused by HSV 2. However, either virus can infect either location. If you or your child experience 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 pain in or around the genital area, or if you have pain with urination or sexual activity, look for redness, swelling, sores, or blisters in or around the affected area, which may indicate HSV-2. Regardless, you should check for lesions if you think you could have been exposed to the infection. Know, though, that genital herpes infections are often asymptomatic. Labs and TestsIf you have symptoms of HSV type 1 or 2, your healthcare provider can diagnose a herpes infection by looking at your skin and/or by swabbing the sores to test for the herpes virus. If you do not have obvious symptoms, a blood test can help determine whether you have an infection. Swab TestingThe gold standard for herpes diagnosis is a viral culture test or nucleic acid amplification test (NAT) of a sample of skin, crust, or fluid from a lesion. This is usually obtained with a gentle swab of the area. A viral culture is a test that allows the virus to grow in a laboratory setting. The NAT tests for the genetic material of the virus in the sample. These tests should only come back positive if you have the virus present in the lesion. In general, the results of the test are reliable if you have active lesions. Herpes Blood TestsIt is possible to screen for asymptomatic herpes infections using a blood test. Herpes blood tests can detect antibodies to the herpes virus. You form these proteins when you need to fight an infection. Generally, it takes about two weeks for your body to produce enough antibodies against herpes to be detectable. The presence of antibodies is evidence that your body has confronted an infection, either recently or in the past. The antibodies can last for years or even a lifetime, which is why using this test to identify reinfection is not helpful. There are two kinds of blood tests for herpes:
There are several different brands of blood tests that are used to detect viral proteins, and there are pros and cons for 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:
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, it is a good idea to wait at least a month or two after your exposure before getting an HSV-2 antibody test. This is because it takes time for your body to make antibodies that can be detected in the blood. Testing before these antibodies develop can lead to a false-negative result. There is some possibility that herpes blood tests may detect antibodies to similar viruses. 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 yield a positive result. In NewbornsThe diagnosis of neonatal herpes—infection passed to a child during or after childbirth—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 specific tests such as a spinal tap. Differential DiagnosesThere are a few other conditions that can be confused with cold sores or genital herpes. Some of these 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.
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Elizabeth Boskey, PhD Thanks for your feedback! Can you get a positive herpes test without an outbreak?Symptoms of HSV are often short-lived and mild.
Many people who test positive for herpes antibodies have no symptoms; often, they can't recall even a single outbreak.
Can you test negative for herpes without an outbreak?If the infection occurred very recently (within a few weeks to 3 months), the test may be negative, but you may still be infected. This is called a false negative. It can take up to 3 months after a possible herpes exposure for this test to be positive.
Does herpes always show up on STD test?If you didn't know before now, herpes is generally not included in a standard STD panel. That means all those screens that you so diligently obtained since becoming sexually active and the one you may have asked your partner to get as well, probably did not include herpes.
Does having herpes antibodies mean you have herpes?If your test result is positive, it can mean that you have an active herpes infection without symptoms. It can also mean that you had an HSV infection in the past. The antibody blood test is not as reliable as culturing a sample from a herpes sore.
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