The rash associated with the Zika virus is a combination of flat blotches (macules) and raised tiny reddish bumps (papules). The technical name for the rash is “maculopapular.” It’s often itchy.

The Zika virus is spread by the bite of an infected Aedes mosquito. Transmission is also possible from mother to fetus or by sexual intercourse, blood transfusion, or animal bite.

The virus is usually mild, and in about 80 percent of cases, no symptoms are noticed. When symptoms occur, they can include:

  • rash
  • fever
  • headache
  • fatigue
  • conjunctivitis
  • joint pain

Symptoms usually resolve in two weeks or less.

The virus is named after the Zika forest in Uganda, where it was first described in 1947. Its first widespread occurrence in the Americas was in 2015, when Brazil reported hundreds of thousands of cases of Zika, some with serious complications for pregnant women.

Read on to learn more about the rash that can occur in those who contract Zika.

Most people with Zika have no rash and no other symptoms. In a large Brazilian study, only 38 percent of people with Zika remembered a mosquito bite.

If you get a Zika virus rash, it may appear within 3 to 12 days of a bite from an infected mosquito. The rash often starts on the trunk and spreads to the face, arms, legs, soles, and palms.

The rash is a combination of tiny red bumps and reddish blotches. Other mosquito-borne infections have similar rashes, including dengue and chikungunya. These are classified as flaviviruses.

But unlike these other flavivirus rashes, the Zika rash was reported to be itchy in 79 percent of cases.

Similar rashes can also result from drug reactions, allergies, bacterial infections, and systemic inflammation.

A study in Brazil of confirmed cases of Zika virus noted that in 98 percent of cases, people went to the doctor because they saw the Zika rash.

The Zika virus is transmitted mostly through the bite of an infected mosquito of the Aedes species. The virus enters your lymph nodes and bloodstream. Your immune system’s reaction to the virus can be expressed in a maculopapular rash.

Your doctor will ask you about any recent travel you (or a partner) may have had to areas where Zika is endemic. They’ll want to know if you remember a mosquito bite.

The doctor will also ask about your symptoms and when they began.

Because the Zika virus rash resembles that of other viral infections, your doctor may order a variety of tests to rule out other causes. Blood, urine, and saliva tests can help confirm Zika. New tests are under development.

There is no special treatment for the Zika virus or for the rash. Recommended treatment is similar to that for other flu-like ailments:

  • rest
  • plenty of fluids
  • acetaminophen to reduce fever and pain

The rash usually goes away on its own within 1 to 4 days after it begins.

There aren’t any complications from the Zika rash itself. But there can be serious complications from the Zika virus, especially for pregnant women.

In Brazil, during the 2015 outbreak of Zika virus, there was an increase in babies born with a small head or brain (microcephaly) and other birth defects. The strong scientific consensus is that there’s a causal association with Zika virus in the mother.

In the Americas and Polynesia, there are reports of an increase in meningitis, meningoencephalitis, and Guillain-Barré syndrome associated with Zika virus.

How and if the Zika virus causes these complications is now being researched.

Pregnant women who have a Zika rash are advised to have tests to determine whether the fetus shows signs of microcephaly or other abnormalities. Testing includes ultrasound and a sample of uterine fluids (amniocentesis) to look for Zika virus.

There is currently no vaccine for the Zika virus. Zika virus is usually mild, and most people notice no symptoms. If you have a Zika rash or other virus symptoms, you can expect to recover in two weeks or less.

To prevent the spread of infection to others, protect yourself against mosquito bites for three weeks after you have Zika or have visited a region where Zika is present. If a mosquito bites you while you have the virus, it can then spread the virus to other people that it bites.

The U.S. Centers for Disease Control (CDC) recommends that pregnant women not travel to areas where there is a risk of Zika. The CDC also recommends that pregnant women have condom-protected sex or abstain from sex while they’re pregnant.

The virus stays in urine and semen longer than in blood. Men who have Zika virus should take precautions with their partner during pregnancy or if pregnancy is planned. The CDC recommends that men who have traveled to a region with Zika should use condoms or refrain from sex for six months.

Protecting yourself against mosquito bites is the first line of defense against the Zika virus.

In areas where there’s a risk of Zika, take steps to reduce the mosquito population. This means getting rid of any standing water near the house that could breed mosquitoes, from plant pots to water bottles.

If you live in or are traveling to a region where there’s a risk of Zika:

  • Wear protective clothing including long sleeves, long pants, socks, and shoes.
  • Use an effective mosquito repellent that has at least a 10 percent concentration of DEET.
  • Sleep under a bed net at night and stay in places with window screens.