Papular urticaria is an allergic skin reaction that typically results from insect bites. Itchy bumps often appear on uncovered areas of the skin, such as the face, forearms, and legs.

Papular urticaria is a common condition, especially in the summer months. Bumps on the skin occur due to a hypersensitivity to bug bites. It usually occurs in children but can also affect adults traveling to new areas.

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.

Read more about papular urticaria symptoms, treatment options, and when to contact a doctor.

The first symptoms of papular urticaria are usually bumps that are:

  • itchy
  • inflamed
  • raised
  • the same color as the surrounding skin or red on lighter skin

The bumps may appear in a curved pattern or a line, particularly if the bites are from bed bugs or fleas.

Although they can occur anywhere on the body, the bumps typically appear on exposed areas, such as the legs, forearms, and face.

The bumps — also called hives — are usually very itchy. People often have the urge to scratch, but doing so can break the skin. This can cause infections and scarring.

Each bump usually remains on the skin for a few days up to several weeks. The bumps may disappear quickly, only to reappear elsewhere. Papular urticaria tends to recur, and a new bite can trigger an old reaction.

Although it can look similar, papular urticaria is different from scabies, a skin condition caused by burrowing mites. Scabies is a contagious condition that causes rashes, sores, and thick crusts that last weeks. Scabies bumps are usually smaller and flatter in appearance than those that result from papular urticaria.

How can people identify bug bites?

Many insects in the United States can potentially cause a reaction, leading to papular urticaria. The most common causes are insects that live on cats and dogs, such as fleas and mites. Bed bugs are another common cause.

However, any biting insect can cause papular urticaria.

A 2017 study identified risk factors that made children more likely to get papular urticaria, including:

  • having household pets, which can lead to fleas
  • 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 under 7 years old
  • being affected by poverty
  • having a soil or earth floor in the main bedroom of a house

Papular urticaria in children

Although papular urticaria can affect anyone, it is more prevalent in children than adults. It commonly occurs in children who are 2–7 years old.

As papular urticaria results from a hypersensitivity to bug bites, people become less likely to get it with time. As children become more and more desensitized to common bug bites, they will “outgrow” the condition. Children tend to get papular urticaria because they have never been exposed to a certain insect bite before and have not yet become desensitized to it.

The bumps will usually go away on their own, but over-the-counter (OTC) medications and creams can ease discomfort, reduce swelling, and prevent infection.

If a person is experiencing serious itching or pain, or the bumps do not resolve, they should contact a healthcare professional. A doctor can perform tests to rule out other causes, such as scabies and dermatitis.

The bumps usually go away on their own. People can use OTC creams and medications to manage discomfort but may need a prescription for stronger steroid creams.

Treatments for papular urticaria include:

However, the best way to manage the condition is to take preventive measures. People should cover their skin when outside, wear insect repellent, and treat household pets for fleas.

If a person has papular urticaria, it is also important to get rid of any sources of infestation. They can do this by:

  • treating household pets with flea medication
  • wearing protective clothing
  • using insect repellent
  • treating pet bedding with flea spray
  • spraying an area with insecticide
  • treating carpets and upholstery with a pyrethroid spray, being sure to vacuum afterward
  • checking mattresses for signs of bed bugs

How can people treat hives (urticaria)?

The main complication of papular urticaria is infection. As the condition causes itchy bumps, people can feel a strong urge to scratch.

This can lead to infections through germs on the fingers and nails entering the skin. Skin infections can cause pain and inflammation, which can worsen the condition.

Papular urticaria is a preventable condition.

The best ways to avoid it are by:

  • covering the skin when outside
  • using insect-repellent spray
  • keeping the home free of bugs
  • treating pets with anti-flea medication

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

If a person does get papular urticaria, it usually resolves on its own.

Here are some questions people often ask about papular urticaria.

How do you get rid of papular urticaria?

OTC preparations, such as oral antihistamines, antiseptic creams, and topical steroid creams, can help. In some cases, a doctor may prescribe a stronger medication.

How do you treat papular urticaria at home?

To reduce itching, a person can apply cool compresses or taking an oatmeal bath. Sometimes, spending time in another location, for instance, on holiday, may provide relief.

Taking measures to avoid or prevent fleas and bed bugs can reduce the risk of bites and papular urticaria in the home. This may involve using insecticide sprays and treating pets with anti-flea medications.

Which bugs cause papular urticaria?

Any biting insects can cause it, notably bed bugs and fleas that live on pets. Other possible causes include mosquitoes, gnats, bird mites, carpet beetles, caterpillars, and other insects. However, it can be difficult to distinguish a trigger since it stems from a sensitization process rather than a specific bite.

Papular urticaria is a skin reaction to an insect bite. It can either be an allergy or hypersensitivity. Symptoms include small, raised bumps that are itchy and painful.

The condition usually resolves on its own, and people can manage it with OTC antihistamines and creams. People should avoid scratching the bumps, as this can lead to infection.