Understanding Prurigo Simplex

Prurigo simplex is a form of skin disease. The term prurigo is used to describe the presence of spots on the skin that are extremely itchy. The bumps associated with prurigo simplex are similar to bug bites. Other skin diseases also develop prurigo but are not the same as prurigo simplex.

In prurigo simplex, itchy bumps develop without any provocation. In addition, the spots and rash associated with chronic prurigo and other skin diseases develop after scratching, making them secondary conditions.

This article discusses the causes, symptoms, and treatment options for prurigo simplex.

What Causes Prurigo Simplex? 

While prurigo simplex is typically considered idiopathic (occurring spontaneously or from an unknown cause), some underlying health disorders are commonly associated with the condition.

Conditions such as diabetes and kidney or liver dysfunction have commonly been found alongside prurigo simplex. Mental health disorders have also been linked to the condition, especially in women between 40 and 60.

Symptoms 

The main symptom of prurigo simplex is spots that develop on the skin. These are typically small in size and shaped like domes. In some cases, small blisters form on the skin as well.

When the spots or blisters develop, they are symmetrical, meaning they appear in equal amounts on both sides of the body. The areas of the body most affected include:

• Legs
• Arms
• Buttocks

The head, neck, and torso can also be affected. The one main characterization of the spots is intense itch. People with the disorder may also experience dermographism, a skin condition that appears with swelling or red lines on the skin after only mild pressure or scratching is applied to the area.

Diagnosis

Diagnosing prurigo simplex may require several different tests as it can be caused by many factors. These tests are used to help rule out other causes of prurigo and if there are any other underlying health issues at play. 

A skin biopsy is used to check for other skin conditions such as dermatitis herpetiformis, a herpes-like skin disorder that develops in people with celiac disease.

Immunofluorescence may be used in the diagnostic process of prurigo simplex. This test uses a dye to highlight immune system dysfunction often seen in various types of skin disorders.

Other tests also used to rule out other conditions include:

• Blood tests to examine liver and kidney function.
• Blood tests to determine if the immune system is working properly. This test is done because many skin diseases develop because the immune system attacks healthy skin tissue by mistake.
• CT scans and MRI scans grant healthcare providers a more in-depth look into what’s happening in the skin tissue.

Treatment

There is no cure for prurigo simplex, but once the condition is diagnosed, treatment can begin to manage symptoms. Unfortunately, some of the most common treatments for other skin diseases, such as antihistamines and topical steroids, do not always work well for people with prurigo simplex.

Some effective treatment options include:

• Systemic steroids: Synthetic forms of natural steroids found within the body. These medications are given orally or through a needle directly into a vein (intravenously).
• Phototherapy: Uses ultraviolet light as a way to heal the skin and get rid of symptoms.
• Immune-suppressing medications: Medications like Methotrexate or Cyclosporine work to slow down or stop the immune system from overreacting.
• Psychological medications or therapies

Summary

Prurigo simplex is a form of skin disease that typically develops on its own without the presence of an underlying skin disorder. A person with the condition experiences intense itchiness and raised bumps on the skin. These bumps are typically small and some can develop into blisters.

While the cause isn't well known, some factors come into play regarding how it develops. These factors can include extreme hot or cold exposure and a person's overall stress level. Certain health conditions that affect the kidneys, liver, or the way the body processes food into energy can also play a role. Prurigo simplex has also been associated with mental health disorders.

Diagnosing the condition early using various blood tests, scans, or a skin biopsy to rule out other skin disorders is important to start treatment. While treatment will not be able to completely cure prurigo simplex, there are several effective treatment options that relieve symptoms.

A Word From Verywell 

Dealing with the intense itchiness involved in prurigo simplex can be excruciating, especially if you are not sure what is causing it. Discuss any type of new intense itches or bumps with your healthcare provider. These disorders are often easy to cope with once treatment is in place. Getting diagnosed quickly can keep you from having to deal with the symptoms longer than you have to.