Yellow Crystals Coming Out of Mosquito Bite (5 Ways To Know If It’s Infected)

Share this article:

The so-called yellow crystals that form out of your mosquito bite are called serous fluid and are a reaction of our body to the sting of the bite. While bites don’t often trigger much physical discomfort, they may cause a bad reaction, better known as the Skeeter syndrome. Mosquito bites are also famous for the many viruses it carries, like Dengue, Malaria, and yellow fever. These bites can also trigger an infection that you can quickly notice due to various symptoms like the collection of pus and the spread of redness and itchiness. You can treat your affected area by using a cold compress and washing thoroughly. Better yet, you can prevent all this annoyance by taking additional precautions when you’re outdoors.

We’ve all been jabbed by that one pesky mosquito at some point in our lives. For most of us, it’s nothing to be concerned about. But maybe a few of us have had a strong reaction to a mosquito bite.

While mosquito bites may seem harmless at the start, they can even be deadly over time because of the various viruses that certain mosquitoes carry.

Sometimes even an infection from a mosquito bite can trigger complications in our bodies.

Therefore, we need to be on alert to notice when a mosquito bite triggers certain reactions or overreactions in our body, as it might just be a call for help.

What are the yellow crystals coming out of mosquito bites? What is the skeeter syndrome, and how is it connected to mosquitoes?

What are the diseases you can contract from mosquito bites? How can you know if your mosquito bite is infected? What can you do about bad mosquito bites, and more importantly, how do you prevent such bites?

What are the yellow crystals coming out of a mosquito bite?

These yellow crystals you notice exiting the mosquito bite are called serous fluid.

While it’s not a common factor in all mosquito bites, it can be seen among a few that have a bad reaction to insect bites.

A 2011 study reported a child having a large local reaction to a mosquito bite, with a small amount of serous fluid draining and crystalizing from the area of the mosquito bite. 

You may have questions about why and how this happens. This serous fluid contains the elements in our blood that react to inflammation, infection, and irritation.

As our body feels the sting of the mosquito bite, our immune system emits this serum that can get dry up and crystallize, leaving a yellowish bump on your skin.

During this reaction process, you might also get an irresistible urge to itch the affected area.

What is skeeter syndrome?

A minor reaction to a mosquito bite should always be expected. It might be a tiny bump, minor itchiness, or a certain redness that lasts a day or two.

A mosquito is biting a persons skin

Minor reactions always clear up within a few days, rarely lasting even a week. You might not even notice them, but in certain instances, you might experience a more severe reaction. This is what’s known as the skeeter syndrome.

Usually, this syndrome is triggered when the mosquito has made contact with your skin for over 6 seconds.

When this happens, you’ll notice a larger area of swelling, soreness, itching, pain, and redness in the specific location of the bite or even along the surrounding area.

This reaction can worsen in a few hours and span weeks. Apart from the swelling, your skin might even develop a bump, blister, or dark spots that seem to represent an injury.

This syndrome is also associated with systemic symptoms such as fever and vomiting on severe occasions, according to a 2012 study conducted by the US National Library of Medicine. 

The best way to manage this syndrome is by preventing mosquito bites using repellents and protective clothing.

Diseases you can contract with mosquito bites

Mosquito bites are a bigger deal than we think.

We have already seen how a simple mosquito bite has led to the spread of deadly viruses seen in the world, like Dengue.

The table below contains a list of diseases that can be contracted from mosquitoes, along with the symptoms.

Malaria – This is one of the oldest diseases known to humankind. While it may be deadly if left untreated, treatments are available in most parts of the world.The most common symptoms include fever, vomiting, chills, diarrhea, abdominal pain, and muscle and joint aches.
Dengue – This is most common in tropical areas and is caused by the Aedes aegypti mosquitoes. Once the virus starts attacking your blood vessels, your platelet count can drop and cause a severe threat to your life.The most common symptoms include severe migraines, swollen glands, vomiting, and bone, joint, and muscle pains. You might even experience pain in your eyes.
Yellow fever – This disease is caused by the same type of mosquito that causes Dengue. The danger of this disease is that symptoms often appear too late, and therefore the disease would have progressed to life-threatening levels by then.Symptoms like nausea, headaches, dizziness, and loss of appetite may be expected. Once the disease has progressed, you might also experience jaundice, abdominal pains, brain dysfunctions, and bleeding through the nose, eyes, and mouth.
Chikungunya – This is a less severe disease when compared to the others. But it still can cause a lot of discomfort in your muscles and joints.Common symptoms of Chikungunya include sudden fluctuations of fever, nausea, maculopapular rash, and conjunctivitis.
Zika virus – This virus, while not so harmful to the average person, has a negative impact on pregnant women as it can cause severe birth defects like brain damage in babies.While most people may not show any symptoms, others may experience joint pains, rashes, red eyes, fever, and abdominal pain.

How can you know if your mosquito bite is infected?

Scratching a mosquito bite can be a rather addicting thing to do. But by doing so, you’re also worsening the mild irritation to something much bigger.

The infection associated with mosquito bites is known as cellulitis. The infection happens when bacteria make their way through your punctured skin.

The following symptoms will help you self-diagnose an infection:

  1. Spreading of the bite – This refers to the swelling of your lymph nodes and the escalation of the redness of the mosquito bite. If you circle the area of your initial mosquito bite, you can notice the pace at which the bite spreads by yourself.
  2. Pus – Even after you clean the bite with soap and water, if the pus keeps reproducing, it might very well be a sign of infection.
  3. Warmth – Due to the inflammation that comes with an infection, you’ll notice a constant warmth in your affected area.
  4. Chills – You should never ignore chills after a bad mosquito bite, as it could also be a symptom of yellow fever. When you experience a risky symptom, you should immediately schedule an appointment with your doctor.
  5. Fever – Fever exceeding the point of 100 degrees Fahrenheit or 37.7 degrees Celsius should also be taken seriously, especially if the fever is accompanied by one or more of the symptoms mentioned above.

What can you do for bad mosquito bites?

To avoid the nasty bumps, blisters, and discomfort mosquitoes give you, you can resort to various home remedies as listed below.

A man is sitting down scratching his very itchy mosquito bite
  1. Wash – To make sure no bacteria enter through your mosquito bite, you need to wash the affected area with soap and water.
  2. Cold compress – If you’re experiencing increased swelling and itchiness, apply an ice pack for a few minutes and repeat the process a few times until it subsides.
  3. Mixture – concoct a mixture of baking soda and water if you want to relieve the itchiness. The effectiveness of this mixture was shown in a 2018 study conducted by the US National Library of Medicine. 
  4. Over-the-counter medication – You can also purchase antihistamine creams from a pharmacy to minimize the itch.

Treating your mosquito bite isn’t all you can do. You can also take measures to ensure that you never have to go through this horrible experience again by following simple instructions.

Always pack that handy insect repellent when you’re on vacation to a tropical country.

Using mosquito netting when you’re sleeping outside, eliminating still water that gets collected in the rain, and wearing long pants and long sleeves during outdoor activities can make all the difference in not being bitten by a pesky mosquito and any other insect for that matter.


Well, sure, maybe taking that extra precaution to avoid getting bitten by a mosquito may seem dramatic. But the result could save you quite a lot of pain.

According to the World Health Organization, it was reported that mosquito bites produce more than 1 million deaths every year.

This is not a number that should be taken lightly.

While that occasional yellow crystal forming out of a mosquito bite may not pose much of a threat, the possible diseases that can come with a mosquito bite need to be taken seriously.

As we all know, the numbers don’t lie!

Share this article:

Was this article helpful?
Kavisha Rodrigo
I'm a sports person that enjoys researching into pushing the limitations of the human body. When it comes to health, I'm a big fan of working out and staying healthy. For hobbies, I'm a big fan of Pokemon and Coldplay.

We’re proud to be a team of writers who are truly passionate about all things health.

Coming together from all parts of the world, we share a common goal of helping serve many with our comprehensive research and clear writing style. Learn more.

Nutrition & Diet