Papular urticaria is the medical term for an allergic skin reaction or hypersensitivity to insect bites. The word papule refers to a solid bump on the skin. Urticaria is another word for hives, which are round, red welts on the skin that itch severely.

One unique characteristic of this skin disorder is that scratching an area affected by a bug bite can trigger the inflammation of old bites. As a result, it can appear as though there are more new bites than there really are.

Papular urticaria. Image credit: Alborz Fallah, (2013, December 16)Share on Pinterest
Papular urticaria appears as clusters of red bumps on the skin.
Image credit: Alborz Fallah, (2013, December 16)

The symptoms of papular urticaria include numerous reddened skin bumps, which usually appear in clusters. The bumps tend to be around 1/12 to 3/4 of an inch in diameter.

At times, the bumps may form scabs or fluid-filled blisters.

The bumps may appear in a curve shape, or in a line, particularly when caused by bed bugs or fleas.

These bumps erupt every few days. They appear most often on the legs, forearms, and face, but have been known to occur in small clusters all over the body.

Some people may notice a central and very small round spot differing in color and appearance from the surrounding tissues. This kind of spot is known as a punctum.

As the result of continuous bug bites, an increase or decrease in the color of the skin may occur.

This type of skin breakout is long-term and comes back repeatedly

The skin bumps are usually accompanied by intense itching, which can lead to severe infections and scarring from constant scratching. When the bumps are scratched, they may become infected, painful, and can become full of pus.

Each bump usually remains on the skin for a few days and up to several weeks.

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Fleabites are one of the most common causes of papular urticaria.

The most prevalent types of insect bites involved in the disorder come from fleas and mosquitoes.

Other insects that have been known to cause papular urticaria include:

  • carpet beetles
  • bed bugs
  • bird mites
  • caterpillars
  • caddisflies
  • insects that live in masonry
  • other insects

A recent study of 2,437 children, published in the World Allergy Organization Journal, revealed that 20 percent of the children in the study had papular urticaria.

In 50 percent of the children, fleabites caused the condition. Other major risk factors identified in the study included:

  • presence of fleas in the home
  • having household pets
  • using a mattress without springs
  • daily use of public transportation
  • living in a warm, tropical climate
  • living in a geographic area heavily infested with insects
  • having siblings with a history of atopic dermatitis
  • being aged under 7 years
  • being raised in poverty

Sometimes, symptoms of papular urticaria improve when a family takes a vacation or moves to a new home. When this happens, it suggests that the cause of the problem is most likely an infestation in the living environment.

Papular urticaria in children

Although adults can be affected, papular urticaria is more common in children than in adults. It most commonly occurs in children aged from 2 to 7 years.

Children often outgrow the disease because they become desensitized, which is a process of becoming immune to an allergen after repeated exposure.

As soon as a person detects signs and symptoms, it is time to see a healthcare professional. They might carry out some testing to rule out other causes of the itchy bumps and prescribe medication to treat the symptoms.

More serious diseases might be the underlying cause of skin bumps. These include:

It is essential to visit the doctor who can rule out other, more serious disorders.

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Steroid cream may be recommended to treat itchy spots.

There are several ways of treating papular urticaria. A person who has the condition can take the following steps:

  • Apply moderately strong steroid cream to the effected itchy spots right away.
  • Take oral antihistamine medication at night to reduce itching and promote sleep.
  • Apply antibiotic cream or give oral systemic antibiotics to treat or prevent secondary infection caused by scratching.
  • Cover exposed skin and use an insect repellent when outside.

It is also important to get rid of the source of the infestation that has caused the problem. People who want to remove an infestation can take the following steps:

  • Treat all household pets with flea medication.
  • Treat pet bedding with flea spray.
  • Spray the home, classroom, or bus with insecticide, being sure to follow instructions carefully.
  • Treat carpets and upholstery with a pyrethroid spray, being sure to vacuum afterward.
  • Check mattresses for signs of bed bugs.
  • Contact certified pest control agency to treat bed bug infestations.

To recap, the three most common appearances of papular urticaria are:

  • small, raised red patches on the skin that may or may not be fluid-filled
  • bumps appearing mostly in clusters, that erupt at old insect bite sites
  • itchy bumps that may last from several days to several weeks

Papular urticaria is a preventable condition. The best way to prevent popular urticaria is to implement a plan to control the presence of fleas and other insects in the home, classroom, and on public transport.

Over time, most children and adults will eventually become desensitized to papular urticaria.