Dengue Symptoms: What to Watch For After Travel

Dengue begins abruptly, 5 to 7 days after an infected mosquito bites you, with high-grade fever of 101.3 °F (38.5 °C) or higher, a severe headache, pain behind the eyes, and deep bone, joint and muscle ache. Nearly every case diagnosed in the United States was acquired somewhere else. The dangerous turn does not come at the peak of the fever — it comes when the fever falls.

What the first week feels like

Per the CDC Yellow Book, symptomatic dengue starts suddenly and brings:

• Fever lasting 2 to 7 days, sometimes biphasic — it drops, then returns
• Severe headache and retro-orbital pain, an ache felt behind the eyeballs
• Bone, joint or muscle pain intense enough to have earned the old name “breakbone fever”
• Nausea and vomiting
• A rash, which StatPearls places 2 to 6 days after fever onset
• Minor bleeding, such as gum or nose bleeding, in some cases

Not everyone gets any of this. The Yellow Book estimates 40% to 80% of infections are asymptomatic, which is why a returning traveler can carry the virus without ever feeling sick.

Where people in the United States pick it up

This is the part a translated Brazilian page gets wrong. In the US, dengue is mostly a travel diagnosis. The Yellow Book counted 7,528 travel-related cases from 2010 through 2021, with 3,135 hospitalizations and 19 deaths, and more than 1,400 travel-associated cases reported in each of 2019 and 2022 through 2024.

Local transmission happens too, in two different settings:

1. US territories and freely associated states — Puerto Rico, the US Virgin Islands, American Samoa and Guam, where the virus circulates rather than visits.
2. Sporadic mainland outbreaks — the Yellow Book names limited local transmission in Florida, Hawaii and Texas, plus cases in Arizona in 2022 and California in 2023.

If you had a fever within two weeks of returning from the Caribbean, Central or South America, South or Southeast Asia, or the Pacific Islands, say so to the clinician. It changes the workup.

The fever breaks, and that is the moment to pay attention

Dengue runs in three stages. The febrile phase covers the first 2 to 7 days. Then comes the critical phase, which the Yellow Book times at 24 to 48 hours and StatPearls places around defervescence on days 4 to 6 — the exact window in which someone can look like they are recovering while plasma is leaking out of the circulation. Recovery follows.

The practical rule: the day the fever drops is not the day to stop watching. That is when the list in dengue warning signs becomes urgent rather than academic.

Acetaminophen only — no aspirin, no ibuprofen

There is no antiviral for dengue. Care is fluids, rest and fever control, and the choice of painkiller is a real clinical decision, not a footnote. The Yellow Book instructs patients to use acetaminophen and tepid sponge baths, and to avoid medications with anticoagulant properties, including aspirin, aspirin-containing drugs and other NSAIDs. StatPearls gives the reason: those drugs interfere with platelet function and raise bleeding risk in an illness that already drops the platelet count. MedlinePlus states it in plain words — do not take aspirin or ibuprofen.

That rule applies before the diagnosis is confirmed, which is why the same caution follows any mosquito-borne fever picked up in a dengue area, including chikungunya symptoms.

Children, older adults and pregnancy

StatPearls lists extremes of age — young children and older adults — along with pregnancy, diabetes, hypertension, kidney and cardiovascular disease as factors raising the risk of the severe form. In children the picture is harder to read: a toddler cannot describe pain behind the eyes, so caregivers end up watching for the fever curve, refusal to drink, unusual sleepiness and irritability instead. Rash plus fever in a child has a long list of other explanations, which is the subject of red spots on skin and fever.

Get medical care the same day if

• Severe belly pain or tenderness
• Vomiting at least three times in 24 hours
• Bleeding from the nose or gums, or blood in vomit or stool
• Extreme tiredness, restlessness or irritability
• Feeling faint or dizzy on standing

Any single one of these is enough. Do not wait for a combination, and do not self-treat with an anti-inflammatory in the meantime.

This content is informational and does not replace medical consultation, diagnosis, or treatment. See also dengue warning signs and zika virus symptoms.