Papular urticaria is an allergic reaction to insect bites or stings causing itchy red bumps on the skin. Some bumps called vesicles or bullae can become fluid-filled blisters, depending on size.

Keep reading to learn more about this condition.

Urticaria is the medical term for hives. Papular urticaria is a type of hive caused by an exaggerated immune response to the bites of insects like mosquitoes, fleas, or bedbugs.

It’s more common in children and tends to affect mostly children under the age of 7. However, it can also affect adults.

Papular urticaria usually presents as follows:

  • Itchy, red bumps or blisters: These appear in clusters on the body and may disappear and reappear. They may leave behind a mark on the skin that’s darker than your skin tone.
  • Symmetry and size: The bumps are usually evenly distributed, and each bump is usually between 0.2-2 centimeters (cm) in diameter.
  • Length of symptoms: The bumps usually appear in the late spring and summer, and the lesions can last for days to weeks before clearing up. The bumps can reappear because of new insect bites and stings or continued environmental insect exposure.

Papular urticaria is not contagious. It can appear because of an allergic reaction to the presence of insects. Some of the common causes of papular urticaria are bites from:

Learn how to get rid of bed bugs.

Typically, a doctor will diagnose papular urticaria by observing your symptoms. If you’ve had a recent insect bite in the affected area, it will make the diagnosis more likely.

That said, the doctor may need to biopsy the area in order to identify the distinctive microscopic appearance of the bite area.

What can be mistaken for papular urticaria?

In the diagnosis process, your doctor will rule out other skin conditions, such as:

Several treatment options are available for papular urticaria. Most of them address the symptoms of the condition.

Medications your doctor may prescribe or recommend include:

  • topical steroids
  • oral anti-inflammatory corticosteroids
  • systemic antihistamines
  • topical or oral antibiotics

How can I treat papular urticaria at home?

There are over-the-counter options you can try, such as:

However, these treatment options may not be appropriate for children. Talk with your doctor about treatments that are safe for your child. Your doctor can also help you determine the correct dosage.

You can take several measures to prevent papular urticaria from occurring. The first is to eliminate the source of the problem. The second is to regularly check for insect infestations and treat them.

  • Use pesticide and insecticide treatments to reduce populations of mosquitoes and other insects around your house.
  • Use flea control medications and treatments on pets and livestock.
  • Use bug sprays on children and adults that are safe and recommended by a doctor.
  • Wear protective clothing when outside or in areas with large insect populations.
  • Limit the amount of time you spend in areas with many insects.
  • Consider using insecticide-treated bed nets and clothing in areas with many mosquitoes.
  • Eliminate bed bug infestations in the home.
  • Regularly inspect pets and livestock for fleas and mites. Take immediate action to treat them.
  • Give pets frequent baths.
  • Wash all bedding and cloth items that pets sleep on to reduce the chance of infestations.
  • Vacuum the entire indoor area of your home to pick up fleas, flea eggs, and other insects. Carefully dispose of the vacuum bags to avoid reintroducing the insects into the environment.
  • Avoid keeping chickens or pet birds in the home because of the risk of mites.

Learn more: How to get rid of fleas »

The primary complication of papular urticaria is a secondary infection. This can develop if you scratch the itchy area, break the skin, and introduce bacteria.

In rare cases, such an infection can lead to a deeper skin infection called cellulitis and even sepsis, which is an infection of the blood.

In some cases, you can also develop cutaneous vasculitis, which is the inflammation of blood vessels in the skin.

Papular urticaria is likely to recur. The condition can return because of continued exposure to the allergen. Children can sometimes outgrow it by building tolerance.

After repeated exposure, the reactions may stop. This varies from person to person, and it can take weeks, months, or years to stop.

If you or your child is experiencing symptoms that could be popular urticaria, you may want to see a doctor so that they can rule out other medical conditions.

Your doctor may do a skin examination or skin biopsy to determine the cause of the bumps and blisters.

If a secondary infection is present because of scratching, then it may be necessary to see a doctor immediately.