The kissing bug, also called the triatomine bug, may appear harmless at first. But it can carry Trypanosoma cruzi, the parasite responsible for Chagas disease—a serious illness that often develops silently over years. One of the greatest risks of a kissing bug bite is that many people never realize they’ve been bitten. Recognizing early signs is crucial for protecting your long-term health.

Why Kissing Bug Bites Often Go Unnoticed

Unlike mosquitoes, kissing bugs usually bite at night while people are asleep. They are attracted to carbon dioxide and tend to bite the face, lips, eyes, or neck—hence the nickname “kissing bug.”

The bite is typically painless because the bug injects an anesthetic substance. You may never wake up or feel anything unusual.

The real danger isn’t the bite itself but the parasite, which can enter the body if infected bug feces accidentally get into the wound, eyes, or mouth.

Early Local Symptoms at the Bite Site

One of the first signs is localized skin irritation, which may include:

• Redness or mild swelling at the bite area

• Itching or a rash resembling a mosquito or bed bug bite

• A firm or slightly painful lump under the skin

In many cases, these symptoms disappear within a few days, which is why they are often ignored.

Swelling Around the Eye (Romaña Sign)

A distinctive early sign of Chagas infection is swelling around one eye, known as Romaña sign. This occurs when parasite-contaminated feces enter the eye after a bite near the face.

The eyelid may appear puffy, reddish, and inflamed—usually without much pain. While not everyone develops this sign, it is a strong indicator of early infection and requires immediate medical attention.

Flu-Like Symptoms That Seem Unrelated

Within a few weeks of being bitten, some people may develop mild flu-like symptoms, including:

• Fever

• Fatigue or weakness

• Headaches

• Muscle or joint pain

• Loss of appetite

Because these symptoms resemble a common viral illness, they are often overlooked or misdiagnosed.

Swollen Lymph Nodes

Another early warning sign is swollen lymph nodes, particularly near the bite site. This occurs as the immune system responds to the parasite. Lymph nodes in the neck, armpits, or groin may feel tender or enlarged.